summaryrefslogtreecommitdiffstats
path: root/fs
AgeCommit message (Collapse)Author
2021-02-17ovl: expand warning in ovl_d_real()Miklos Szeredi
commit cef4cbff06fbc3be54d6d79ee139edecc2ee8598 upstream. There was a syzbot report with this warning but insufficient information... Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-02-17ovl: skip getxattr of security labelsAmir Goldstein
[ Upstream commit 03fedf93593c82538b18476d8c4f0e8f8435ea70 ] When inode has no listxattr op of its own (e.g. squashfs) vfs_listxattr calls the LSM inode_listsecurity hooks to list the xattrs that LSMs will intercept in inode_getxattr hooks. When selinux LSM is installed but not initialized, it will list the security.selinux xattr in inode_listsecurity, but will not intercept it in inode_getxattr. This results in -ENODATA for a getxattr call for an xattr returned by listxattr. This situation was manifested as overlayfs failure to copy up lower files from squashfs when selinux is built-in but not initialized, because ovl_copy_xattr() iterates the lower inode xattrs by vfs_listxattr() and vfs_getxattr(). ovl_copy_xattr() skips copy up of security labels that are indentified by inode_copy_up_xattr LSM hooks, but it does that after vfs_getxattr(). Since we are not going to copy them, skip vfs_getxattr() of the security labels. Reported-by: Michael Labriola <michael.d.labriola@gmail.com> Tested-by: Michael Labriola <michael.d.labriola@gmail.com> Link: https://lore.kernel.org/linux-unionfs/2nv9d47zt7.fsf@aldarion.sourceruckus.org/ Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-02-17ovl: perform vfs_getxattr() with mounter credsMiklos Szeredi
[ Upstream commit 554677b97257b0b69378bd74e521edb7e94769ff ] The vfs_getxattr() in ovl_xattr_set() is used to check whether an xattr exist on a lower layer file that is to be removed. If the xattr does not exist, then no need to copy up the file. This call of vfs_getxattr() wasn't wrapped in credential override, and this is probably okay. But for consitency wrap this instance as well. Reported-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-02-13squashfs: add more sanity checks in xattr id lookupPhillip Lougher
commit 506220d2ba21791314af569211ffd8870b8208fa upstream. Sysbot has reported a warning where a kmalloc() attempt exceeds the maximum limit. This has been identified as corruption of the xattr_ids count when reading the xattr id lookup table. This patch adds a number of additional sanity checks to detect this corruption and others. 1. It checks for a corrupted xattr index read from the inode. This could be because the metadata block is uncompressed, or because the "compression" bit has been corrupted (turning a compressed block into an uncompressed block). This would cause an out of bounds read. 2. It checks against corruption of the xattr_ids count. This can either lead to the above kmalloc failure, or a smaller than expected table to be read. 3. It checks the contents of the index table for corruption. [phillip@squashfs.org.uk: fix checkpatch issue] Link: https://lkml.kernel.org/r/270245655.754655.1612770082682@webmail.123-reg.co.uk Link: https://lkml.kernel.org/r/20210204130249.4495-5-phillip@squashfs.org.uk Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk> Reported-by: syzbot+2ccea6339d368360800d@syzkaller.appspotmail.com Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-02-13squashfs: add more sanity checks in inode lookupPhillip Lougher
commit eabac19e40c095543def79cb6ffeb3a8588aaff4 upstream. Sysbot has reported an "slab-out-of-bounds read" error which has been identified as being caused by a corrupted "ino_num" value read from the inode. This could be because the metadata block is uncompressed, or because the "compression" bit has been corrupted (turning a compressed block into an uncompressed block). This patch adds additional sanity checks to detect this, and the following corruption. 1. It checks against corruption of the inodes count. This can either lead to a larger table to be read, or a smaller than expected table to be read. In the case of a too large inodes count, this would often have been trapped by the existing sanity checks, but this patch introduces a more exact check, which can identify too small values. 2. It checks the contents of the index table for corruption. [phillip@squashfs.org.uk: fix checkpatch issue] Link: https://lkml.kernel.org/r/527909353.754618.1612769948607@webmail.123-reg.co.uk Link: https://lkml.kernel.org/r/20210204130249.4495-4-phillip@squashfs.org.uk Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk> Reported-by: syzbot+04419e3ff19d2970ea28@syzkaller.appspotmail.com Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-02-13squashfs: add more sanity checks in id lookupPhillip Lougher
commit f37aa4c7366e23f91b81d00bafd6a7ab54e4a381 upstream. Sysbot has reported a number of "slab-out-of-bounds reads" and "use-after-free read" errors which has been identified as being caused by a corrupted index value read from the inode. This could be because the metadata block is uncompressed, or because the "compression" bit has been corrupted (turning a compressed block into an uncompressed block). This patch adds additional sanity checks to detect this, and the following corruption. 1. It checks against corruption of the ids count. This can either lead to a larger table to be read, or a smaller than expected table to be read. In the case of a too large ids count, this would often have been trapped by the existing sanity checks, but this patch introduces a more exact check, which can identify too small values. 2. It checks the contents of the index table for corruption. Link: https://lkml.kernel.org/r/20210204130249.4495-3-phillip@squashfs.org.uk Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk> Reported-by: syzbot+b06d57ba83f604522af2@syzkaller.appspotmail.com Reported-by: syzbot+c021ba012da41ee9807c@syzkaller.appspotmail.com Reported-by: syzbot+5024636e8b5fd19f0f19@syzkaller.appspotmail.com Reported-by: syzbot+bcbc661df46657d0fa4f@syzkaller.appspotmail.com Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-02-13pNFS/NFSv4: Try to return invalid layout in pnfs_layout_process()Trond Myklebust
[ Upstream commit 08bd8dbe88825760e953759d7ec212903a026c75 ] If the server returns a new stateid that does not match the one in our cache, then try to return the one we hold instead of just invalidating it on the client side. This ensures that both client and server will agree that the stateid is invalid. Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-02-10mm: hugetlbfs: fix cannot migrate the fallocated HugeTLB pageMuchun Song
commit 585fc0d2871c9318c949fbf45b1f081edd489e96 upstream. If a new hugetlb page is allocated during fallocate it will not be marked as active (set_page_huge_active) which will result in a later isolate_huge_page failure when the page migration code would like to move that page. Such a failure would be unexpected and wrong. Only export set_page_huge_active, just leave clear_page_huge_active as static. Because there are no external users. Link: https://lkml.kernel.org/r/20210115124942.46403-3-songmuchun@bytedance.com Fixes: 70c3547e36f5 (hugetlbfs: add hugetlbfs_fallocate()) Signed-off-by: Muchun Song <songmuchun@bytedance.com> Acked-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Cc: David Hildenbrand <david@redhat.com> Cc: Yang Shi <shy828301@gmail.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-02-10smb3: fix crediting for compounding when only one request in flightPavel Shilovsky
commit 91792bb8089b63b7b780251eb83939348ac58a64 upstream. Currently we try to guess if a compound request is going to succeed waiting for credits or not based on the number of requests in flight. This approach doesn't work correctly all the time because there may be only one request in flight which is going to bring multiple credits satisfying the compound request. Change the behavior to fail a request only if there are no requests in flight at all and proceed waiting for credits otherwise. Cc: <stable@vger.kernel.org> # 5.1+ Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com> Reviewed-by: Tom Talpey <tom@talpey.com> Reviewed-by: Shyam Prasad N <nspmangalore@gmail.com> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-02-10smb3: Fix out-of-bounds bug in SMB2_negotiate()Gustavo A. R. Silva
commit 8d8d1dbefc423d42d626cf5b81aac214870ebaab upstream. While addressing some warnings generated by -Warray-bounds, I found this bug that was introduced back in 2017: CC [M] fs/cifs/smb2pdu.o fs/cifs/smb2pdu.c: In function ‘SMB2_negotiate’: fs/cifs/smb2pdu.c:822:16: warning: array subscript 1 is above array bounds of ‘__le16[1]’ {aka ‘short unsigned int[1]’} [-Warray-bounds] 822 | req->Dialects[1] = cpu_to_le16(SMB30_PROT_ID); | ~~~~~~~~~~~~~^~~ fs/cifs/smb2pdu.c:823:16: warning: array subscript 2 is above array bounds of ‘__le16[1]’ {aka ‘short unsigned int[1]’} [-Warray-bounds] 823 | req->Dialects[2] = cpu_to_le16(SMB302_PROT_ID); | ~~~~~~~~~~~~~^~~ fs/cifs/smb2pdu.c:824:16: warning: array subscript 3 is above array bounds of ‘__le16[1]’ {aka ‘short unsigned int[1]’} [-Warray-bounds] 824 | req->Dialects[3] = cpu_to_le16(SMB311_PROT_ID); | ~~~~~~~~~~~~~^~~ fs/cifs/smb2pdu.c:816:16: warning: array subscript 1 is above array bounds of ‘__le16[1]’ {aka ‘short unsigned int[1]’} [-Warray-bounds] 816 | req->Dialects[1] = cpu_to_le16(SMB302_PROT_ID); | ~~~~~~~~~~~~~^~~ At the time, the size of array _Dialects_ was changed from 1 to 3 in struct validate_negotiate_info_req, and then in 2019 it was changed from 3 to 4, but those changes were never made in struct smb2_negotiate_req, which has led to a 3 and a half years old out-of-bounds bug in function SMB2_negotiate() (fs/cifs/smb2pdu.c). Fix this by increasing the size of array _Dialects_ in struct smb2_negotiate_req to 4. Fixes: 9764c02fcbad ("SMB3: Add support for multidialect negotiate (SMB2.1 and later)") Fixes: d5c7076b772a ("smb3: add smb3.1.1 to default dialect list") Cc: stable@vger.kernel.org Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-02-10cifs: report error instead of invalid when revalidating a dentry failsAurelien Aptel
commit 21b200d091826a83aafc95d847139b2b0582f6d1 upstream. Assuming - //HOST/a is mounted on /mnt - //HOST/b is mounted on /mnt/b On a slow connection, running 'df' and killing it while it's processing /mnt/b can make cifs_get_inode_info() returns -ERESTARTSYS. This triggers the following chain of events: => the dentry revalidation fail => dentry is put and released => superblock associated with the dentry is put => /mnt/b is unmounted This patch makes cifs_d_revalidate() return the error instead of 0 (invalid) when cifs_revalidate_dentry() fails, except for ENOENT (file deleted) and ESTALE (file recreated). Signed-off-by: Aurelien Aptel <aaptel@suse.com> Suggested-by: Shyam Prasad N <nspmangalore@gmail.com> Reviewed-by: Shyam Prasad N <nspmangalore@gmail.com> CC: stable@vger.kernel.org Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-02-10ovl: fix dentry leak in ovl_get_redirectLiangyan
commit e04527fefba6e4e66492f122cf8cc6314f3cf3bf upstream. We need to lock d_parent->d_lock before dget_dlock, or this may have d_lockref updated parallelly like calltrace below which will cause dentry->d_lockref leak and risk a crash. CPU 0 CPU 1 ovl_set_redirect lookup_fast ovl_get_redirect __d_lookup dget_dlock //no lock protection here spin_lock(&dentry->d_lock) dentry->d_lockref.count++ dentry->d_lockref.count++ [   49.799059] PGD 800000061fed7067 P4D 800000061fed7067 PUD 61fec5067 PMD 0 [   49.799689] Oops: 0002 [#1] SMP PTI [   49.800019] CPU: 2 PID: 2332 Comm: node Not tainted 4.19.24-7.20.al7.x86_64 #1 [   49.800678] Hardware name: Alibaba Cloud Alibaba Cloud ECS, BIOS 8a46cfe 04/01/2014 [   49.801380] RIP: 0010:_raw_spin_lock+0xc/0x20 [   49.803470] RSP: 0018:ffffac6fc5417e98 EFLAGS: 00010246 [   49.803949] RAX: 0000000000000000 RBX: ffff93b8da3446c0 RCX: 0000000a00000000 [   49.804600] RDX: 0000000000000001 RSI: 000000000000000a RDI: 0000000000000088 [   49.805252] RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff993cf040 [   49.805898] R10: ffff93b92292e580 R11: ffffd27f188a4b80 R12: 0000000000000000 [   49.806548] R13: 00000000ffffff9c R14: 00000000fffffffe R15: ffff93b8da3446c0 [   49.807200] FS:  00007ffbedffb700(0000) GS:ffff93b927880000(0000) knlGS:0000000000000000 [   49.807935] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [   49.808461] CR2: 0000000000000088 CR3: 00000005e3f74006 CR4: 00000000003606a0 [   49.809113] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [   49.809758] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [   49.810410] Call Trace: [   49.810653]  d_delete+0x2c/0xb0 [   49.810951]  vfs_rmdir+0xfd/0x120 [   49.811264]  do_rmdir+0x14f/0x1a0 [   49.811573]  do_syscall_64+0x5b/0x190 [   49.811917]  entry_SYSCALL_64_after_hwframe+0x44/0xa9 [   49.812385] RIP: 0033:0x7ffbf505ffd7 [   49.814404] RSP: 002b:00007ffbedffada8 EFLAGS: 00000297 ORIG_RAX: 0000000000000054 [   49.815098] RAX: ffffffffffffffda RBX: 00007ffbedffb640 RCX: 00007ffbf505ffd7 [   49.815744] RDX: 0000000004449700 RSI: 0000000000000000 RDI: 0000000006c8cd50 [   49.816394] RBP: 00007ffbedffaea0 R08: 0000000000000000 R09: 0000000000017d0b [   49.817038] R10: 0000000000000000 R11: 0000000000000297 R12: 0000000000000012 [   49.817687] R13: 00000000072823d8 R14: 00007ffbedffb700 R15: 00000000072823d8 [   49.818338] Modules linked in: pvpanic cirrusfb button qemu_fw_cfg atkbd libps2 i8042 [   49.819052] CR2: 0000000000000088 [   49.819368] ---[ end trace 4e652b8aa299aa2d ]--- [   49.819796] RIP: 0010:_raw_spin_lock+0xc/0x20 [   49.821880] RSP: 0018:ffffac6fc5417e98 EFLAGS: 00010246 [   49.822363] RAX: 0000000000000000 RBX: ffff93b8da3446c0 RCX: 0000000a00000000 [   49.823008] RDX: 0000000000000001 RSI: 000000000000000a RDI: 0000000000000088 [   49.823658] RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff993cf040 [   49.825404] R10: ffff93b92292e580 R11: ffffd27f188a4b80 R12: 0000000000000000 [   49.827147] R13: 00000000ffffff9c R14: 00000000fffffffe R15: ffff93b8da3446c0 [   49.828890] FS:  00007ffbedffb700(0000) GS:ffff93b927880000(0000) knlGS:0000000000000000 [   49.830725] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [   49.832359] CR2: 0000000000000088 CR3: 00000005e3f74006 CR4: 00000000003606a0 [   49.834085] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [   49.835792] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Cc: <stable@vger.kernel.org> Fixes: a6c606551141 ("ovl: redirect on rename-dir") Signed-off-by: Liangyan <liangyan.peng@linux.alibaba.com> Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com> Suggested-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-02-10rxrpc: Fix deadlock around release of dst cached on udp tunnelDavid Howells
[ Upstream commit 5399d52233c47905bbf97dcbaa2d7a9cc31670ba ] AF_RXRPC sockets use UDP ports in encap mode. This causes socket and dst from an incoming packet to get stolen and attached to the UDP socket from whence it is leaked when that socket is closed. When a network namespace is removed, the wait for dst records to be cleaned up happens before the cleanup of the rxrpc and UDP socket, meaning that the wait never finishes. Fix this by moving the rxrpc (and, by dependence, the afs) private per-network namespace registrations to the device group rather than subsys group. This allows cached rxrpc local endpoints to be cleared and their UDP sockets closed before we try waiting for the dst records. The symptom is that lines looking like the following: unregister_netdevice: waiting for lo to become free get emitted at regular intervals after running something like the referenced syzbot test. Thanks to Vadim for tracking this down and work out the fix. Reported-by: syzbot+df400f2f24a1677cd7e0@syzkaller.appspotmail.com Reported-by: Vadim Fedorenko <vfedorenko@novek.ru> Fixes: 5271953cad31 ("rxrpc: Use the UDP encap_rcv hook") Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Vadim Fedorenko <vfedorenko@novek.ru> Link: https://lore.kernel.org/r/161196443016.3868642.5577440140646403533.stgit@warthog.procyon.org.uk Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-02-07udf: fix the problem that the disc content is not displayedlianzhi chang
[ Upstream commit 5cdc4a6950a883594e9640b1decb3fcf6222a594 ] When the capacity of the disc is too large (assuming the 4.7G specification), the disc (UDF file system) will be burned multiple times in the windows (Multisession Usage). When the remaining capacity of the CD is less than 300M (estimated value, for reference only), open the CD in the Linux system, the content of the CD is displayed as blank (the kernel will say "No VRS found"). Windows can display the contents of the CD normally. Through analysis, in the "fs/udf/super.c": udf_check_vsd function, the actual value of VSD_MAX_SECTOR_OFFSET may be much larger than 0x800000. According to the current code logic, it is found that the type of sbi->s_session is "__s32", when the remaining capacity of the disc is less than 300M (take a set of test values: sector=3154903040, sbi->s_session=1540464, sb->s_blocksize_bits=11 ), the calculation result of "sbi->s_session << sb->s_blocksize_bits" will overflow. Therefore, it is necessary to convert the type of s_session to "loff_t" (when udf_check_vsd starts, assign a value to _sector, which is also converted in this way), so that the result will not overflow, and then the content of the disc can be displayed normally. Link: https://lore.kernel.org/r/20210114075741.30448-1-changlianzhi@uniontech.com Signed-off-by: lianzhi chang <changlianzhi@uniontech.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-02-07btrfs: backref, use correct count to resolve normal data refsethanwu
commit b25b0b871f206936d5bca02b80d38c05623e27da upstream. With the following patches: - btrfs: backref, only collect file extent items matching backref offset - btrfs: backref, not adding refs from shared block when resolving normal backref - btrfs: backref, only search backref entries from leaves of the same root we only collect the normal data refs we want, so the imprecise upper bound total_refs of that EXTENT_ITEM could now be changed to the count of the normal backref entry we want to search. Background and how the patches fit together: Btrfs has two types of data backref. For BTRFS_EXTENT_DATA_REF_KEY type of backref, we don't have the exact block number. Therefore, we need to call resolve_indirect_refs. It uses btrfs_search_slot to locate the leaf block. Then we need to walk through the leaves to search for the EXTENT_DATA items that have disk bytenr matching the extent item (add_all_parents). When resolving indirect refs, we could take entries that don't belong to the backref entry we are searching for right now. For that reason when searching backref entry, we always use total refs of that EXTENT_ITEM rather than individual count. For example: item 11 key (40831553536 EXTENT_ITEM 4194304) itemoff 15460 itemsize extent refs 24 gen 7302 flags DATA shared data backref parent 394985472 count 10 #1 extent data backref root 257 objectid 260 offset 1048576 count 3 #2 extent data backref root 256 objectid 260 offset 65536 count 6 #3 extent data backref root 257 objectid 260 offset 65536 count 5 #4 For example, when searching backref entry #4, we'll use total_refs 24, a very loose loop ending condition, instead of total_refs = 5. But using total_refs = 24 is not accurate. Sometimes, we'll never find all the refs from specific root. As a result, the loop keeps on going until we reach the end of that inode. The first 3 patches, handle 3 different types refs we might encounter. These refs do not belong to the normal backref we are searching, and hence need to be skipped. This patch changes the total_refs to correct number so that we could end loop as soon as we find all the refs we want. btrfs send uses backref to find possible clone sources, the following is a simple test to compare the results with and without this patch: $ btrfs subvolume create /sub1 $ for i in `seq 1 163840`; do dd if=/dev/zero of=/sub1/file bs=64K count=1 seek=$((i-1)) conv=notrunc oflag=direct done $ btrfs subvolume snapshot /sub1 /sub2 $ for i in `seq 1 163840`; do dd if=/dev/zero of=/sub1/file bs=4K count=1 seek=$(((i-1)*16+10)) conv=notrunc oflag=direct done $ btrfs subvolume snapshot -r /sub1 /snap1 $ time btrfs send /snap1 | btrfs receive /volume2 Without this patch: real 69m48.124s user 0m50.199s sys 70m15.600s With this patch: real 1m59.683s user 0m35.421s sys 2m42.684s Reviewed-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: ethanwu <ethanwu@synology.com> [ add patchset cover letter with background and numbers ] Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-02-07btrfs: backref, only search backref entries from leaves of the same rootethanwu
commit cfc0eed0ec89db7c4a8d461174cabfaa4a0912c7 upstream. We could have some nodes/leaves in subvolume whose owner are not the that subvolume. In this way, when we resolve normal backrefs of that subvolume, we should avoid collecting those references from these blocks. Reviewed-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: ethanwu <ethanwu@synology.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-02-07btrfs: backref, don't add refs from shared block when resolving normal backrefethanwu
commit ed58f2e66e849c34826083e5a6c1b506ee8a4d8e upstream. All references from the block of SHARED_DATA_REF belong to that shared block backref. For example: item 11 key (40831553536 EXTENT_ITEM 4194304) itemoff 15460 itemsize 95 extent refs 24 gen 7302 flags DATA extent data backref root 257 objectid 260 offset 65536 count 5 extent data backref root 258 objectid 265 offset 0 count 9 shared data backref parent 394985472 count 10 Block 394985472 might be leaf from root 257, and the item obejctid and (file_pos - file_extent_item::offset) in that leaf just happens to be 260 and 65536 which is equal to the first extent data backref entry. Before this patch, when we resolve backref: root 257 objectid 260 offset 65536 we will add those refs in block 394985472 and wrongly treat those as the refs we want. Fix this by checking if the leaf we are processing is shared data backref, if so, just skip this leaf. Shared data refs added into preftrees.direct have all entry value = 0 (root_id = 0, key = NULL, level = 0) except parent entry. Other refs from indirect tree will have key value and root id != 0, and these values won't be changed when their parent is resolved and added to preftrees.direct. Therefore, we could reuse the preftrees.direct and search ref with all values = 0 except parent is set to avoid getting those resolved refs block. Reviewed-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: ethanwu <ethanwu@synology.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-02-07btrfs: backref, only collect file extent items matching backref offsetethanwu
commit 7ac8b88ee668a5b4743ebf3e9888fabac85c334a upstream. When resolving one backref of type EXTENT_DATA_REF, we collect all references that simply reference the EXTENT_ITEM even though their (file_pos - file_extent_item::offset) are not the same as the btrfs_extent_data_ref::offset we are searching for. This patch adds additional check so that we only collect references whose (file_pos - file_extent_item::offset) == btrfs_extent_data_ref::offset. Reviewed-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: ethanwu <ethanwu@synology.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-02-03pNFS/NFSv4: Fix a layout segment leak in pnfs_layout_process()Trond Myklebust
[ Upstream commit 814b84971388cd5fb182f2e914265b3827758455 ] If the server returns a new stateid that does not match the one in our cache, then pnfs_layout_process() will leak the layout segments returned by pnfs_mark_layout_stateid_invalid(). Fixes: 9888d837f3cf ("pNFS: Force a retry of LAYOUTGET if the stateid doesn't match our cache") Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-02-03btrfs: fix possible free space tree corruption with online conversionJosef Bacik
commit 2f96e40212d435b328459ba6b3956395eed8fa9f upstream. While running btrfs/011 in a loop I would often ASSERT() while trying to add a new free space entry that already existed, or get an EEXIST while adding a new block to the extent tree, which is another indication of double allocation. This occurs because when we do the free space tree population, we create the new root and then populate the tree and commit the transaction. The problem is when you create a new root, the root node and commit root node are the same. During this initial transaction commit we will run all of the delayed refs that were paused during the free space tree generation, and thus begin to cache block groups. While caching block groups the caching thread will be reading from the main root for the free space tree, so as we make allocations we'll be changing the free space tree, which can cause us to add the same range twice which results in either the ASSERT(ret != -EEXIST); in __btrfs_add_free_space, or in a variety of different errors when running delayed refs because of a double allocation. Fix this by marking the fs_info as unsafe to load the free space tree, and fall back on the old slow method. We could be smarter than this, for example caching the block group while we're populating the free space tree, but since this is a serious problem I've opted for the simplest solution. CC: stable@vger.kernel.org # 4.9+ Fixes: a5ed91828518 ("Btrfs: implement the free space B-tree") Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-30fs: fix lazytime expiration handling in __writeback_single_inode()Eric Biggers
commit 1e249cb5b7fc09ff216aa5a12f6c302e434e88f9 upstream. When lazytime is enabled and an inode is being written due to its in-memory updated timestamps having expired, either due to a sync() or syncfs() system call or due to dirtytime_expire_interval having elapsed, the VFS needs to inform the filesystem so that the filesystem can copy the inode's timestamps out to the on-disk data structures. This is done by __writeback_single_inode() calling mark_inode_dirty_sync(), which then calls ->dirty_inode(I_DIRTY_SYNC). However, this occurs after __writeback_single_inode() has already cleared the dirty flags from ->i_state. This causes two bugs: - mark_inode_dirty_sync() redirties the inode, causing it to remain dirty. This wastefully causes the inode to be written twice. But more importantly, it breaks cases where sync_filesystem() is expected to clean dirty inodes. This includes the FS_IOC_REMOVE_ENCRYPTION_KEY ioctl (as reported at https://lore.kernel.org/r/20200306004555.GB225345@gmail.com), as well as possibly filesystem freezing (freeze_super()). - Since ->i_state doesn't contain I_DIRTY_TIME when ->dirty_inode() is called from __writeback_single_inode() for lazytime expiration, xfs_fs_dirty_inode() ignores the notification. (XFS only cares about lazytime expirations, and it assumes that i_state will contain I_DIRTY_TIME during those.) Therefore, lazy timestamps aren't persisted by sync(), syncfs(), or dirtytime_expire_interval on XFS. Fix this by moving the call to mark_inode_dirty_sync() to earlier in __writeback_single_inode(), before the dirty flags are cleared from i_state. This makes filesystems be properly notified of the timestamp expiration, and it avoids incorrectly redirtying the inode. This fixes xfstest generic/580 (which tests FS_IOC_REMOVE_ENCRYPTION_KEY) when run on ext4 or f2fs with lazytime enabled. It also fixes the new lazytime xfstest I've proposed, which reproduces the above-mentioned XFS bug (https://lore.kernel.org/r/20210105005818.92978-1-ebiggers@kernel.org). Alternatively, we could call ->dirty_inode(I_DIRTY_SYNC) directly. But due to the introduction of I_SYNC_QUEUED, mark_inode_dirty_sync() is the right thing to do because mark_inode_dirty_sync() now knows not to move the inode to a writeback list if it is currently queued for sync. Fixes: 0ae45f63d4ef ("vfs: add support for a lazytime mount option") Cc: stable@vger.kernel.org Depends-on: 5afced3bf281 ("writeback: Avoid skipping inode writeback") Link: https://lore.kernel.org/r/20210112190253.64307-2-ebiggers@kernel.org Suggested-by: Jan Kara <jack@suse.cz> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-30writeback: Drop I_DIRTY_TIME_EXPIREJan Kara
commit 5fcd57505c002efc5823a7355e21f48dd02d5a51 upstream. The only use of I_DIRTY_TIME_EXPIRE is to detect in __writeback_single_inode() that inode got there because flush worker decided it's time to writeback the dirty inode time stamps (either because we are syncing or because of age). However we can detect this directly in __writeback_single_inode() and there's no need for the strange propagation with I_DIRTY_TIME_EXPIRE flag. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jan Kara <jack@suse.cz> Cc: Eric Biggers <ebiggers@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-30SMB3.1.1: do not log warning message if server doesn't populate saltSteve French
commit 7955f105afb6034af344038d663bc98809483cdd upstream. In the negotiate protocol preauth context, the server is not required to populate the salt (although it is done by most servers) so do not warn on mount. We retain the checks (warn) that the preauth context is the minimum size and that the salt does not exceed DataLength of the SMB response. Although we use the defaults in the case that the preauth context response is invalid, these checks may be useful in the future as servers add support for additional mechanisms. CC: Stable <stable@vger.kernel.org> Reviewed-by: Shyam Prasad N <sprasad@microsoft.com> Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-30io_uring: Fix current->fs handling in io_sq_wq_submit_work()Nicolai Stange
No upstream commit, this is a fix to a stable 5.4 specific backport. The intention of backport commit cac68d12c531 ("io_uring: grab ->fs as part of async offload") as found in the stable 5.4 tree was to make io_sq_wq_submit_work() to switch the workqueue task's ->fs over to the submitting task's one during the IO operation. However, due to a small logic error, this change turned out to not have any actual effect. From a high level, the relevant code in io_sq_wq_submit_work() looks like old_fs_struct = current->fs; do { ... if (req->fs != current->fs && current->fs != old_fs_struct) { task_lock(current); if (req->fs) current->fs = req->fs; else current->fs = old_fs_struct; task_unlock(current); } ... } while (req); The if condition is supposed to cover the case that current->fs doesn't match what's needed for processing the request, but observe how it fails to ever evaluate to true due to the second clause: current->fs != old_fs_struct will be false in the first iteration as per the initialization of old_fs_struct and because this prevents current->fs from getting replaced, the same follows inductively for all subsequent iterations. Fix said if condition such that - if req->fs is set and doesn't match current->fs, the latter will be switched to the former - or if req->fs is unset, the switch back to the initial old_fs_struct will be made, if necessary. While at it, also correct the condition for the ->fs related cleanup right before the return of io_sq_wq_submit_work(): currently, old_fs_struct is restored only if it's non-NULL. It is always non-NULL though and thus, the if-condition is rendundant. Supposedly, the motivation had been to optimize and avoid switching current->fs back to the initial old_fs_struct in case it is found to have the desired value already. Make it so. Cc: stable@vger.kernel.org # v5.4 Fixes: cac68d12c531 ("io_uring: grab ->fs as part of async offload") Reviewed-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Nicolai Stange <nstange@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-27cifs: do not fail __smb_send_rqst if non-fatal signals are pendingRonnie Sahlberg
commit 214a5ea081e77346e4963dd6d20c5539ff8b6ae6 upstream. RHBZ 1848178 The original intent of returning an error in this function in the patch: "CIFS: Mask off signals when sending SMB packets" was to avoid interrupting packet send in the middle of sending the data (and thus breaking an SMB connection), but we also don't want to fail the request for non-fatal signals even before we have had a chance to try to send it (the reported problem could be reproduced e.g. by exiting a child process when the parent process was in the midst of calling futimens to update a file's timestamps). In addition, since the signal may remain pending when we enter the sending loop, we may end up not sending the whole packet before TCP buffers become full. In this case the code returns -EINTR but what we need here is to return -ERESTARTSYS instead to allow system calls to be restarted. Fixes: b30c74c73c78 ("CIFS: Mask off signals when sending SMB packets") Cc: stable@vger.kernel.org # v5.1+ Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com> Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-27btrfs: send: fix invalid clone operations when cloning from the same file ↵Filipe Manana
and root commit 518837e65068c385dddc0a87b3e577c8be7c13b1 upstream. When an incremental send finds an extent that is shared, it checks which file extent items in the range refer to that extent, and for those it emits clone operations, while for others it emits regular write operations to avoid corruption at the destination (as described and fixed by commit d906d49fc5f4 ("Btrfs: send, fix file corruption due to incorrect cloning operations")). However when the root we are cloning from is the send root, we are cloning from the inode currently being processed and the source file range has several extent items that partially point to the desired extent, with an offset smaller than the offset in the file extent item for the range we want to clone into, it can cause the algorithm to issue a clone operation that starts at the current eof of the file being processed in the receiver side, in which case the receiver will fail, with EINVAL, when attempting to execute the clone operation. Example reproducer: $ cat test-send-clone.sh #!/bin/bash DEV=/dev/sdi MNT=/mnt/sdi mkfs.btrfs -f $DEV >/dev/null mount $DEV $MNT # Create our test file with a single and large extent (1M) and with # different content for different file ranges that will be reflinked # later. xfs_io -f \ -c "pwrite -S 0xab 0 128K" \ -c "pwrite -S 0xcd 128K 128K" \ -c "pwrite -S 0xef 256K 256K" \ -c "pwrite -S 0x1a 512K 512K" \ $MNT/foobar btrfs subvolume snapshot -r $MNT $MNT/snap1 btrfs send -f /tmp/snap1.send $MNT/snap1 # Now do a series of changes to our file such that we end up with # different parts of the extent reflinked into different file offsets # and we overwrite a large part of the extent too, so no file extent # items refer to that part that was overwritten. This used to confuse # the algorithm used by the kernel to figure out which file ranges to # clone, making it attempt to clone from a source range starting at # the current eof of the file, resulting in the receiver to fail since # it is an invalid clone operation. # xfs_io -c "reflink $MNT/foobar 64K 1M 960K" \ -c "reflink $MNT/foobar 0K 512K 256K" \ -c "reflink $MNT/foobar 512K 128K 256K" \ -c "pwrite -S 0x73 384K 640K" \ $MNT/foobar btrfs subvolume snapshot -r $MNT $MNT/snap2 btrfs send -f /tmp/snap2.send -p $MNT/snap1 $MNT/snap2 echo -e "\nFile digest in the original filesystem:" md5sum $MNT/snap2/foobar # Now unmount the filesystem, create a new one, mount it and try to # apply both send streams to recreate both snapshots. umount $DEV mkfs.btrfs -f $DEV >/dev/null mount $DEV $MNT btrfs receive -f /tmp/snap1.send $MNT btrfs receive -f /tmp/snap2.send $MNT # Must match what we got in the original filesystem of course. echo -e "\nFile digest in the new filesystem:" md5sum $MNT/snap2/foobar umount $MNT When running the reproducer, the incremental send operation fails due to an invalid clone operation: $ ./test-send-clone.sh wrote 131072/131072 bytes at offset 0 128 KiB, 32 ops; 0.0015 sec (80.906 MiB/sec and 20711.9741 ops/sec) wrote 131072/131072 bytes at offset 131072 128 KiB, 32 ops; 0.0013 sec (90.514 MiB/sec and 23171.6148 ops/sec) wrote 262144/262144 bytes at offset 262144 256 KiB, 64 ops; 0.0025 sec (98.270 MiB/sec and 25157.2327 ops/sec) wrote 524288/524288 bytes at offset 524288 512 KiB, 128 ops; 0.0052 sec (95.730 MiB/sec and 24506.9883 ops/sec) Create a readonly snapshot of '/mnt/sdi' in '/mnt/sdi/snap1' At subvol /mnt/sdi/snap1 linked 983040/983040 bytes at offset 1048576 960 KiB, 1 ops; 0.0006 sec (1.419 GiB/sec and 1550.3876 ops/sec) linked 262144/262144 bytes at offset 524288 256 KiB, 1 ops; 0.0020 sec (120.192 MiB/sec and 480.7692 ops/sec) linked 262144/262144 bytes at offset 131072 256 KiB, 1 ops; 0.0018 sec (133.833 MiB/sec and 535.3319 ops/sec) wrote 655360/655360 bytes at offset 393216 640 KiB, 160 ops; 0.0093 sec (66.781 MiB/sec and 17095.8436 ops/sec) Create a readonly snapshot of '/mnt/sdi' in '/mnt/sdi/snap2' At subvol /mnt/sdi/snap2 File digest in the original filesystem: 9c13c61cb0b9f5abf45344375cb04dfa /mnt/sdi/snap2/foobar At subvol snap1 At snapshot snap2 ERROR: failed to clone extents to foobar: Invalid argument File digest in the new filesystem: 132f0396da8f48d2e667196bff882cfc /mnt/sdi/snap2/foobar The clone operation is invalid because its source range starts at the current eof of the file in the receiver, causing the receiver to get an EINVAL error from the clone operation when attempting it. For the example above, what happens is the following: 1) When processing the extent at file offset 1M, the algorithm checks that the extent is shared and can be (fully or partially) found at file offset 0. At this point the file has a size (and eof) of 1M at the receiver; 2) It finds that our extent item at file offset 1M has a data offset of 64K and, since the file extent item at file offset 0 has a data offset of 0, it issues a clone operation, from the same file and root, that has a source range offset of 64K, destination offset of 1M and a length of 64K, since the extent item at file offset 0 refers only to the first 128K of the shared extent. After this clone operation, the file size (and eof) at the receiver is increased from 1M to 1088K (1M + 64K); 3) Now there's still 896K (960K - 64K) of data left to clone or write, so it checks for the next file extent item, which starts at file offset 128K. This file extent item has a data offset of 0 and a length of 256K, so a clone operation with a source range offset of 256K, a destination offset of 1088K (1M + 64K) and length of 128K is issued. After this operation the file size (and eof) at the receiver increases from 1088K to 1216K (1088K + 128K); 4) Now there's still 768K (896K - 128K) of data left to clone or write, so it checks for the next file extent item, located at file offset 384K. This file extent item points to a different extent, not the one we want to clone, with a length of 640K. So we issue a write operation into the file range 1216K (1088K + 128K, end of the last clone operation), with a length of 640K and with a data matching the one we can find for that range in send root. After this operation, the file size (and eof) at the receiver increases from 1216K to 1856K (1216K + 640K); 5) Now there's still 128K (768K - 640K) of data left to clone or write, so we look into the file extent item, which is for file offset 1M and it points to the extent we want to clone, with a data offset of 64K and a length of 960K. However this matches the file offset we started with, the start of the range to clone into. So we can't for sure find any file extent item from here onwards with the rest of the data we want to clone, yet we proceed and since the file extent item points to the shared extent, with a data offset of 64K, we issue a clone operation with a source range starting at file offset 1856K, which matches the file extent item's offset, 1M, plus the amount of data cloned and written so far, which is 64K (step 2) + 128K (step 3) + 640K (step 4). This clone operation is invalid since the source range offset matches the current eof of the file in the receiver. We should have stopped looking for extents to clone at this point and instead fallback to write, which would simply the contain the data in the file range from 1856K to 1856K + 128K. So fix this by stopping the loop that looks for file ranges to clone at clone_range() when we reach the current eof of the file being processed, if we are cloning from the same file and using the send root as the clone root. This ensures any data not yet cloned will be sent to the receiver through a write operation. A test case for fstests will follow soon. Reported-by: Massimo B. <massimo.b@gmx.net> Link: https://lore.kernel.org/linux-btrfs/6ae34776e85912960a253a8327068a892998e685.camel@gmx.net/ Fixes: 11f2069c113e ("Btrfs: send, allow clone operations within the same file") CC: stable@vger.kernel.org # 5.5+ Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-27btrfs: don't clear ret in btrfs_start_dirty_block_groupsJosef Bacik
commit 34d1eb0e599875064955a74712f08ff14c8e3d5f upstream. If we fail to update a block group item in the loop we'll break, however we'll do btrfs_run_delayed_refs and lose our error value in ret, and thus not clean up properly. Fix this by only running the delayed refs if there was no failure. CC: stable@vger.kernel.org # 4.4+ Reviewed-by: Qu Wenruo <wqu@suse.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-27btrfs: fix lockdep splat in btrfs_recover_relocationJosef Bacik
commit fb286100974e7239af243bc2255a52f29442f9c8 upstream. While testing the error paths of relocation I hit the following lockdep splat: ====================================================== WARNING: possible circular locking dependency detected 5.10.0-rc6+ #217 Not tainted ------------------------------------------------------ mount/779 is trying to acquire lock: ffffa0e676945418 (&fs_info->balance_mutex){+.+.}-{3:3}, at: btrfs_recover_balance+0x2f0/0x340 but task is already holding lock: ffffa0e60ee31da8 (btrfs-root-00){++++}-{3:3}, at: __btrfs_tree_read_lock+0x27/0x100 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (btrfs-root-00){++++}-{3:3}: down_read_nested+0x43/0x130 __btrfs_tree_read_lock+0x27/0x100 btrfs_read_lock_root_node+0x31/0x40 btrfs_search_slot+0x462/0x8f0 btrfs_update_root+0x55/0x2b0 btrfs_drop_snapshot+0x398/0x750 clean_dirty_subvols+0xdf/0x120 btrfs_recover_relocation+0x534/0x5a0 btrfs_start_pre_rw_mount+0xcb/0x170 open_ctree+0x151f/0x1726 btrfs_mount_root.cold+0x12/0xea legacy_get_tree+0x30/0x50 vfs_get_tree+0x28/0xc0 vfs_kern_mount.part.0+0x71/0xb0 btrfs_mount+0x10d/0x380 legacy_get_tree+0x30/0x50 vfs_get_tree+0x28/0xc0 path_mount+0x433/0xc10 __x64_sys_mount+0xe3/0x120 do_syscall_64+0x33/0x40 entry_SYSCALL_64_after_hwframe+0x44/0xa9 -> #1 (sb_internal#2){.+.+}-{0:0}: start_transaction+0x444/0x700 insert_balance_item.isra.0+0x37/0x320 btrfs_balance+0x354/0xf40 btrfs_ioctl_balance+0x2cf/0x380 __x64_sys_ioctl+0x83/0xb0 do_syscall_64+0x33/0x40 entry_SYSCALL_64_after_hwframe+0x44/0xa9 -> #0 (&fs_info->balance_mutex){+.+.}-{3:3}: __lock_acquire+0x1120/0x1e10 lock_acquire+0x116/0x370 __mutex_lock+0x7e/0x7b0 btrfs_recover_balance+0x2f0/0x340 open_ctree+0x1095/0x1726 btrfs_mount_root.cold+0x12/0xea legacy_get_tree+0x30/0x50 vfs_get_tree+0x28/0xc0 vfs_kern_mount.part.0+0x71/0xb0 btrfs_mount+0x10d/0x380 legacy_get_tree+0x30/0x50 vfs_get_tree+0x28/0xc0 path_mount+0x433/0xc10 __x64_sys_mount+0xe3/0x120 do_syscall_64+0x33/0x40 entry_SYSCALL_64_after_hwframe+0x44/0xa9 other info that might help us debug this: Chain exists of: &fs_info->balance_mutex --> sb_internal#2 --> btrfs-root-00 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(btrfs-root-00); lock(sb_internal#2); lock(btrfs-root-00); lock(&fs_info->balance_mutex); *** DEADLOCK *** 2 locks held by mount/779: #0: ffffa0e60dc040e0 (&type->s_umount_key#47/1){+.+.}-{3:3}, at: alloc_super+0xb5/0x380 #1: ffffa0e60ee31da8 (btrfs-root-00){++++}-{3:3}, at: __btrfs_tree_read_lock+0x27/0x100 stack backtrace: CPU: 0 PID: 779 Comm: mount Not tainted 5.10.0-rc6+ #217 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-2.fc32 04/01/2014 Call Trace: dump_stack+0x8b/0xb0 check_noncircular+0xcf/0xf0 ? trace_call_bpf+0x139/0x260 __lock_acquire+0x1120/0x1e10 lock_acquire+0x116/0x370 ? btrfs_recover_balance+0x2f0/0x340 __mutex_lock+0x7e/0x7b0 ? btrfs_recover_balance+0x2f0/0x340 ? btrfs_recover_balance+0x2f0/0x340 ? rcu_read_lock_sched_held+0x3f/0x80 ? kmem_cache_alloc_trace+0x2c4/0x2f0 ? btrfs_get_64+0x5e/0x100 btrfs_recover_balance+0x2f0/0x340 open_ctree+0x1095/0x1726 btrfs_mount_root.cold+0x12/0xea ? rcu_read_lock_sched_held+0x3f/0x80 legacy_get_tree+0x30/0x50 vfs_get_tree+0x28/0xc0 vfs_kern_mount.part.0+0x71/0xb0 btrfs_mount+0x10d/0x380 ? __kmalloc_track_caller+0x2f2/0x320 legacy_get_tree+0x30/0x50 vfs_get_tree+0x28/0xc0 ? capable+0x3a/0x60 path_mount+0x433/0xc10 __x64_sys_mount+0xe3/0x120 do_syscall_64+0x33/0x40 entry_SYSCALL_64_after_hwframe+0x44/0xa9 This is straightforward to fix, simply release the path before we setup the balance_ctl. CC: stable@vger.kernel.org # 4.4+ Reviewed-by: Qu Wenruo <wqu@suse.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-27btrfs: don't get an EINTR during drop_snapshot for relocJosef Bacik
commit 18d3bff411c8d46d40537483bdc0b61b33ce0371 upstream. This was partially fixed by f3e3d9cc3525 ("btrfs: avoid possible signal interruption of btrfs_drop_snapshot() on relocation tree"), however it missed a spot when we restart a trans handle because we need to end the transaction. The fix is the same, simply use btrfs_join_transaction() instead of btrfs_start_transaction() when deleting reloc roots. Fixes: f3e3d9cc3525 ("btrfs: avoid possible signal interruption of btrfs_drop_snapshot() on relocation tree") CC: stable@vger.kernel.org # 5.4+ Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-23nfsd4: readdirplus shouldn't return parent of exportJ. Bruce Fields
commit 51b2ee7d006a736a9126e8111d1f24e4fd0afaa6 upstream. If you export a subdirectory of a filesystem, a READDIRPLUS on the root of that export will return the filehandle of the parent with the ".." entry. The filehandle is optional, so let's just not return the filehandle for ".." if we're at the root of an export. Note that once the client learns one filehandle outside of the export, they can trivially access the rest of the export using further lookups. However, it is also not very difficult to guess filehandles outside of the export. So exporting a subdirectory of a filesystem should considered equivalent to providing access to the entire filesystem. To avoid confusion, we recommend only exporting entire filesystems. Reported-by: Youjipeng <wangzhibei1999@gmail.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-19ext4: fix superblock checksum failure when setting password saltJan Kara
commit dfd56c2c0c0dbb11be939b804ddc8d5395ab3432 upstream. When setting password salt in the superblock, we forget to recompute the superblock checksum so it will not match until the next superblock modification which recomputes the checksum. Fix it. CC: Michael Halcrow <mhalcrow@google.com> Reported-by: Andreas Dilger <adilger@dilger.ca> Fixes: 9bd8212f981e ("ext4 crypto: add encryption policy and password salt support") Signed-off-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20201216101844.22917-8-jack@suse.cz Signed-off-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-19NFS: nfs_igrab_and_active must first reference the superblockTrond Myklebust
commit 896567ee7f17a8a736cda8a28cc987228410a2ac upstream. Before referencing the inode, we must ensure that the superblock can be referenced. Otherwise, we can end up with iput() calling superblock operations that are no longer valid or accessible. Fixes: ea7c38fef0b7 ("NFSv4: Ensure we reference the inode for return-on-close in delegreturn") Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-19NFS/pNFS: Fix a leak of the layout 'plh_outstanding' counterTrond Myklebust
commit cb2856c5971723910a86b7d1d0cf623d6919cbc4 upstream. If we exit _lgopen_prepare_attached() without setting a layout, we will currently leak the plh_outstanding counter. Fixes: 411ae722d10a ("pNFS: Wait for stale layoutget calls to complete in pnfs_update_layout()") Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-19pNFS: Stricter ordering of layoutget and layoutreturnTrond Myklebust
commit 2c8d5fc37fe2384a9bdb6965443ab9224d46f704 upstream. If a layout return is in progress, we should wait for it to complete, in case the layout segment we are picking up gets returned too. Fixes: 30cb3ee299cb ("pNFS: Handle NFS4ERR_OLD_STATEID on layoutreturn by bumping the state seqid") Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-19pNFS: Mark layout for return if return-on-close was not sentTrond Myklebust
commit 67bbceedc9bb8ad48993a8bd6486054756d711f4 upstream. If the layout return-on-close failed because the layoutreturn was never sent, then we should mark the layout for return again. Fixes: 9c47b18cf722 ("pNFS: Ensure we do clear the return-on-close layout stateid on fatal errors") Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-19pNFS: We want return-on-close to complete when evicting the inodeTrond Myklebust
commit 078000d02d57f02dde61de4901f289672e98c8bc upstream. If the inode is being evicted, it should be safe to run return-on-close, so we should do it to ensure we don't inadvertently leak layout segments. Fixes: 1c5bd76d17cc ("pNFS: Enable layoutreturn operation for return-on-close") Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-19NFS4: Fix use-after-free in trace_event_raw_event_nfs4_set_lockDave Wysochanski
commit 3d1a90ab0ed93362ec8ac85cf291243c87260c21 upstream. It is only safe to call the tracepoint before rpc_put_task() because 'data' is freed inside nfs4_lock_release (rpc_release). Fixes: 48c9579a1afe ("Adding stateid information to tracepoints") Signed-off-by: Dave Wysochanski <dwysocha@redhat.com> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-19btrfs: fix transaction leak and crash after RO remount caused by qgroup rescanFilipe Manana
[ Upstream commit cb13eea3b49055bd78e6ddf39defd6340f7379fc ] If we remount a filesystem in RO mode while the qgroup rescan worker is running, we can end up having it still running after the remount is done, and at unmount time we may end up with an open transaction that ends up never getting committed. If that happens we end up with several memory leaks and can crash when hardware acceleration is unavailable for crc32c. Possibly it can lead to other nasty surprises too, due to use-after-free issues. The following steps explain how the problem happens. 1) We have a filesystem mounted in RW mode and the qgroup rescan worker is running; 2) We remount the filesystem in RO mode, and never stop/pause the rescan worker, so after the remount the rescan worker is still running. The important detail here is that the rescan task is still running after the remount operation committed any ongoing transaction through its call to btrfs_commit_super(); 3) The rescan is still running, and after the remount completed, the rescan worker started a transaction, after it finished iterating all leaves of the extent tree, to update the qgroup status item in the quotas tree. It does not commit the transaction, it only releases its handle on the transaction; 4) A filesystem unmount operation starts shortly after; 5) The unmount task, at close_ctree(), stops the transaction kthread, which had not had a chance to commit the open transaction since it was sleeping and the commit interval (default of 30 seconds) has not yet elapsed since the last time it committed a transaction; 6) So after stopping the transaction kthread we still have the transaction used to update the qgroup status item open. At close_ctree(), when the filesystem is in RO mode and no transaction abort happened (or the filesystem is in error mode), we do not expect to have any transaction open, so we do not call btrfs_commit_super(); 7) We then proceed to destroy the work queues, free the roots and block groups, etc. After that we drop the last reference on the btree inode by calling iput() on it. Since there are dirty pages for the btree inode, corresponding to the COWed extent buffer for the quotas btree, btree_write_cache_pages() is invoked to flush those dirty pages. This results in creating a bio and submitting it, which makes us end up at btrfs_submit_metadata_bio(); 8) At btrfs_submit_metadata_bio() we end up at the if-then-else branch that calls btrfs_wq_submit_bio(), because check_async_write() returned a value of 1. This value of 1 is because we did not have hardware acceleration available for crc32c, so BTRFS_FS_CSUM_IMPL_FAST was not set in fs_info->flags; 9) Then at btrfs_wq_submit_bio() we call btrfs_queue_work() against the workqueue at fs_info->workers, which was already freed before by the call to btrfs_stop_all_workers() at close_ctree(). This results in an invalid memory access due to a use-after-free, leading to a crash. When this happens, before the crash there are several warnings triggered, since we have reserved metadata space in a block group, the delayed refs reservation, etc: ------------[ cut here ]------------ WARNING: CPU: 4 PID: 1729896 at fs/btrfs/block-group.c:125 btrfs_put_block_group+0x63/0xa0 [btrfs] Modules linked in: btrfs dm_snapshot dm_thin_pool (...) CPU: 4 PID: 1729896 Comm: umount Tainted: G B W 5.10.0-rc4-btrfs-next-73 #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014 RIP: 0010:btrfs_put_block_group+0x63/0xa0 [btrfs] Code: f0 01 00 00 48 39 c2 75 (...) RSP: 0018:ffffb270826bbdd8 EFLAGS: 00010206 RAX: 0000000000000001 RBX: ffff947ed73e4000 RCX: ffff947ebc8b29c8 RDX: 0000000000000001 RSI: ffffffffc0b150a0 RDI: ffff947ebc8b2800 RBP: ffff947ebc8b2800 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000001 R12: ffff947ed73e4110 R13: ffff947ed73e4160 R14: ffff947ebc8b2988 R15: dead000000000100 FS: 00007f15edfea840(0000) GS:ffff9481ad600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f37e2893320 CR3: 0000000138f68001 CR4: 00000000003706e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: btrfs_free_block_groups+0x17f/0x2f0 [btrfs] close_ctree+0x2ba/0x2fa [btrfs] generic_shutdown_super+0x6c/0x100 kill_anon_super+0x14/0x30 btrfs_kill_super+0x12/0x20 [btrfs] deactivate_locked_super+0x31/0x70 cleanup_mnt+0x100/0x160 task_work_run+0x68/0xb0 exit_to_user_mode_prepare+0x1bb/0x1c0 syscall_exit_to_user_mode+0x4b/0x260 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7f15ee221ee7 Code: ff 0b 00 f7 d8 64 89 01 48 (...) RSP: 002b:00007ffe9470f0f8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007f15ee347264 RCX: 00007f15ee221ee7 RDX: ffffffffffffff78 RSI: 0000000000000000 RDI: 000056169701d000 RBP: 0000561697018a30 R08: 0000000000000000 R09: 00007f15ee2e2be0 R10: 000056169701efe0 R11: 0000000000000246 R12: 0000000000000000 R13: 000056169701d000 R14: 0000561697018b40 R15: 0000561697018c60 irq event stamp: 0 hardirqs last enabled at (0): [<0000000000000000>] 0x0 hardirqs last disabled at (0): [<ffffffff8bcae560>] copy_process+0x8a0/0x1d70 softirqs last enabled at (0): [<ffffffff8bcae560>] copy_process+0x8a0/0x1d70 softirqs last disabled at (0): [<0000000000000000>] 0x0 ---[ end trace dd74718fef1ed5c6 ]--- ------------[ cut here ]------------ WARNING: CPU: 2 PID: 1729896 at fs/btrfs/block-rsv.c:459 btrfs_release_global_block_rsv+0x70/0xc0 [btrfs] Modules linked in: btrfs dm_snapshot dm_thin_pool (...) CPU: 2 PID: 1729896 Comm: umount Tainted: G B W 5.10.0-rc4-btrfs-next-73 #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014 RIP: 0010:btrfs_release_global_block_rsv+0x70/0xc0 [btrfs] Code: 48 83 bb b0 03 00 00 00 (...) RSP: 0018:ffffb270826bbdd8 EFLAGS: 00010206 RAX: 000000000033c000 RBX: ffff947ed73e4000 RCX: 0000000000000000 RDX: 0000000000000001 RSI: ffffffffc0b0d8c1 RDI: 00000000ffffffff RBP: ffff947ebc8b7000 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000001 R12: ffff947ed73e4110 R13: ffff947ed73e5278 R14: dead000000000122 R15: dead000000000100 FS: 00007f15edfea840(0000) GS:ffff9481aca00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000561a79f76e20 CR3: 0000000138f68006 CR4: 00000000003706e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: btrfs_free_block_groups+0x24c/0x2f0 [btrfs] close_ctree+0x2ba/0x2fa [btrfs] generic_shutdown_super+0x6c/0x100 kill_anon_super+0x14/0x30 btrfs_kill_super+0x12/0x20 [btrfs] deactivate_locked_super+0x31/0x70 cleanup_mnt+0x100/0x160 task_work_run+0x68/0xb0 exit_to_user_mode_prepare+0x1bb/0x1c0 syscall_exit_to_user_mode+0x4b/0x260 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7f15ee221ee7 Code: ff 0b 00 f7 d8 64 89 01 (...) RSP: 002b:00007ffe9470f0f8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007f15ee347264 RCX: 00007f15ee221ee7 RDX: ffffffffffffff78 RSI: 0000000000000000 RDI: 000056169701d000 RBP: 0000561697018a30 R08: 0000000000000000 R09: 00007f15ee2e2be0 R10: 000056169701efe0 R11: 0000000000000246 R12: 0000000000000000 R13: 000056169701d000 R14: 0000561697018b40 R15: 0000561697018c60 irq event stamp: 0 hardirqs last enabled at (0): [<0000000000000000>] 0x0 hardirqs last disabled at (0): [<ffffffff8bcae560>] copy_process+0x8a0/0x1d70 softirqs last enabled at (0): [<ffffffff8bcae560>] copy_process+0x8a0/0x1d70 softirqs last disabled at (0): [<0000000000000000>] 0x0 ---[ end trace dd74718fef1ed5c7 ]--- ------------[ cut here ]------------ WARNING: CPU: 2 PID: 1729896 at fs/btrfs/block-group.c:3377 btrfs_free_block_groups+0x25d/0x2f0 [btrfs] Modules linked in: btrfs dm_snapshot dm_thin_pool (...) CPU: 5 PID: 1729896 Comm: umount Tainted: G B W 5.10.0-rc4-btrfs-next-73 #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014 RIP: 0010:btrfs_free_block_groups+0x25d/0x2f0 [btrfs] Code: ad de 49 be 22 01 00 (...) RSP: 0018:ffffb270826bbde8 EFLAGS: 00010206 RAX: ffff947ebeae1d08 RBX: ffff947ed73e4000 RCX: 0000000000000000 RDX: 0000000000000001 RSI: ffff947e9d823ae8 RDI: 0000000000000246 RBP: ffff947ebeae1d08 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000001 R12: ffff947ebeae1c00 R13: ffff947ed73e5278 R14: dead000000000122 R15: dead000000000100 FS: 00007f15edfea840(0000) GS:ffff9481ad200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f1475d98ea8 CR3: 0000000138f68005 CR4: 00000000003706e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: close_ctree+0x2ba/0x2fa [btrfs] generic_shutdown_super+0x6c/0x100 kill_anon_super+0x14/0x30 btrfs_kill_super+0x12/0x20 [btrfs] deactivate_locked_super+0x31/0x70 cleanup_mnt+0x100/0x160 task_work_run+0x68/0xb0 exit_to_user_mode_prepare+0x1bb/0x1c0 syscall_exit_to_user_mode+0x4b/0x260 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7f15ee221ee7 Code: ff 0b 00 f7 d8 64 89 (...) RSP: 002b:00007ffe9470f0f8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007f15ee347264 RCX: 00007f15ee221ee7 RDX: ffffffffffffff78 RSI: 0000000000000000 RDI: 000056169701d000 RBP: 0000561697018a30 R08: 0000000000000000 R09: 00007f15ee2e2be0 R10: 000056169701efe0 R11: 0000000000000246 R12: 0000000000000000 R13: 000056169701d000 R14: 0000561697018b40 R15: 0000561697018c60 irq event stamp: 0 hardirqs last enabled at (0): [<0000000000000000>] 0x0 hardirqs last disabled at (0): [<ffffffff8bcae560>] copy_process+0x8a0/0x1d70 softirqs last enabled at (0): [<ffffffff8bcae560>] copy_process+0x8a0/0x1d70 softirqs last disabled at (0): [<0000000000000000>] 0x0 ---[ end trace dd74718fef1ed5c8 ]--- BTRFS info (device sdc): space_info 4 has 268238848 free, is not full BTRFS info (device sdc): space_info total=268435456, used=114688, pinned=0, reserved=16384, may_use=0, readonly=65536 BTRFS info (device sdc): global_block_rsv: size 0 reserved 0 BTRFS info (device sdc): trans_block_rsv: size 0 reserved 0 BTRFS info (device sdc): chunk_block_rsv: size 0 reserved 0 BTRFS info (device sdc): delayed_block_rsv: size 0 reserved 0 BTRFS info (device sdc): delayed_refs_rsv: size 524288 reserved 0 And the crash, which only happens when we do not have crc32c hardware acceleration, produces the following trace immediately after those warnings: stack segment: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC PTI CPU: 2 PID: 1749129 Comm: umount Tainted: G B W 5.10.0-rc4-btrfs-next-73 #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014 RIP: 0010:btrfs_queue_work+0x36/0x190 [btrfs] Code: 54 55 53 48 89 f3 (...) RSP: 0018:ffffb27082443ae8 EFLAGS: 00010282 RAX: 0000000000000004 RBX: ffff94810ee9ad90 RCX: 0000000000000000 RDX: 0000000000000001 RSI: ffff94810ee9ad90 RDI: ffff947ed8ee75a0 RBP: a56b6b6b6b6b6b6b R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000007 R11: 0000000000000001 R12: ffff947fa9b435a8 R13: ffff94810ee9ad90 R14: 0000000000000000 R15: ffff947e93dc0000 FS: 00007f3cfe974840(0000) GS:ffff9481ac600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f1b42995a70 CR3: 0000000127638003 CR4: 00000000003706e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: btrfs_wq_submit_bio+0xb3/0xd0 [btrfs] btrfs_submit_metadata_bio+0x44/0xc0 [btrfs] submit_one_bio+0x61/0x70 [btrfs] btree_write_cache_pages+0x414/0x450 [btrfs] ? kobject_put+0x9a/0x1d0 ? trace_hardirqs_on+0x1b/0xf0 ? _raw_spin_unlock_irqrestore+0x3c/0x60 ? free_debug_processing+0x1e1/0x2b0 do_writepages+0x43/0xe0 ? lock_acquired+0x199/0x490 __writeback_single_inode+0x59/0x650 writeback_single_inode+0xaf/0x120 write_inode_now+0x94/0xd0 iput+0x187/0x2b0 close_ctree+0x2c6/0x2fa [btrfs] generic_shutdown_super+0x6c/0x100 kill_anon_super+0x14/0x30 btrfs_kill_super+0x12/0x20 [btrfs] deactivate_locked_super+0x31/0x70 cleanup_mnt+0x100/0x160 task_work_run+0x68/0xb0 exit_to_user_mode_prepare+0x1bb/0x1c0 syscall_exit_to_user_mode+0x4b/0x260 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7f3cfebabee7 Code: ff 0b 00 f7 d8 64 89 01 (...) RSP: 002b:00007ffc9c9a05f8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007f3cfecd1264 RCX: 00007f3cfebabee7 RDX: ffffffffffffff78 RSI: 0000000000000000 RDI: 0000562b6b478000 RBP: 0000562b6b473a30 R08: 0000000000000000 R09: 00007f3cfec6cbe0 R10: 0000562b6b479fe0 R11: 0000000000000246 R12: 0000000000000000 R13: 0000562b6b478000 R14: 0000562b6b473b40 R15: 0000562b6b473c60 Modules linked in: btrfs dm_snapshot dm_thin_pool (...) ---[ end trace dd74718fef1ed5cc ]--- Finally when we remove the btrfs module (rmmod btrfs), there are several warnings about objects that were allocated from our slabs but were never freed, consequence of the transaction that was never committed and got leaked: ============================================================================= BUG btrfs_delayed_ref_head (Tainted: G B W ): Objects remaining in btrfs_delayed_ref_head on __kmem_cache_shutdown() ----------------------------------------------------------------------------- INFO: Slab 0x0000000094c2ae56 objects=24 used=2 fp=0x000000002bfa2521 flags=0x17fffc000010200 CPU: 5 PID: 1729921 Comm: rmmod Tainted: G B W 5.10.0-rc4-btrfs-next-73 #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014 Call Trace: dump_stack+0x8d/0xb5 slab_err+0xb7/0xdc ? lock_acquired+0x199/0x490 __kmem_cache_shutdown+0x1ac/0x3c0 ? lock_release+0x20e/0x4c0 kmem_cache_destroy+0x55/0x120 btrfs_delayed_ref_exit+0x11/0x35 [btrfs] exit_btrfs_fs+0xa/0x59 [btrfs] __x64_sys_delete_module+0x194/0x260 ? fpregs_assert_state_consistent+0x1e/0x40 ? exit_to_user_mode_prepare+0x55/0x1c0 ? trace_hardirqs_on+0x1b/0xf0 do_syscall_64+0x33/0x80 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7f693e305897 Code: 73 01 c3 48 8b 0d f9 f5 (...) RSP: 002b:00007ffcf73eb508 EFLAGS: 00000206 ORIG_RAX: 00000000000000b0 RAX: ffffffffffffffda RBX: 0000559df504f760 RCX: 00007f693e305897 RDX: 000000000000000a RSI: 0000000000000800 RDI: 0000559df504f7c8 RBP: 00007ffcf73eb568 R08: 0000000000000000 R09: 0000000000000000 R10: 00007f693e378ac0 R11: 0000000000000206 R12: 00007ffcf73eb740 R13: 00007ffcf73ec5a6 R14: 0000559df504f2a0 R15: 0000559df504f760 INFO: Object 0x0000000050cbdd61 @offset=12104 INFO: Allocated in btrfs_add_delayed_tree_ref+0xbb/0x480 [btrfs] age=1894 cpu=6 pid=1729873 __slab_alloc.isra.0+0x109/0x1c0 kmem_cache_alloc+0x7bb/0x830 btrfs_add_delayed_tree_ref+0xbb/0x480 [btrfs] btrfs_free_tree_block+0x128/0x360 [btrfs] __btrfs_cow_block+0x489/0x5f0 [btrfs] btrfs_cow_block+0xf7/0x220 [btrfs] btrfs_search_slot+0x62a/0xc40 [btrfs] btrfs_del_orphan_item+0x65/0xd0 [btrfs] btrfs_find_orphan_roots+0x1bf/0x200 [btrfs] open_ctree+0x125a/0x18a0 [btrfs] btrfs_mount_root.cold+0x13/0xed [btrfs] legacy_get_tree+0x30/0x60 vfs_get_tree+0x28/0xe0 fc_mount+0xe/0x40 vfs_kern_mount.part.0+0x71/0x90 btrfs_mount+0x13b/0x3e0 [btrfs] INFO: Freed in __btrfs_run_delayed_refs+0x1117/0x1290 [btrfs] age=4292 cpu=2 pid=1729526 kmem_cache_free+0x34c/0x3c0 __btrfs_run_delayed_refs+0x1117/0x1290 [btrfs] btrfs_run_delayed_refs+0x81/0x210 [btrfs] commit_cowonly_roots+0xfb/0x300 [btrfs] btrfs_commit_transaction+0x367/0xc40 [btrfs] sync_filesystem+0x74/0x90 generic_shutdown_super+0x22/0x100 kill_anon_super+0x14/0x30 btrfs_kill_super+0x12/0x20 [btrfs] deactivate_locked_super+0x31/0x70 cleanup_mnt+0x100/0x160 task_work_run+0x68/0xb0 exit_to_user_mode_prepare+0x1bb/0x1c0 syscall_exit_to_user_mode+0x4b/0x260 entry_SYSCALL_64_after_hwframe+0x44/0xa9 INFO: Object 0x0000000086e9b0ff @offset=12776 INFO: Allocated in btrfs_add_delayed_tree_ref+0xbb/0x480 [btrfs] age=1900 cpu=6 pid=1729873 __slab_alloc.isra.0+0x109/0x1c0 kmem_cache_alloc+0x7bb/0x830 btrfs_add_delayed_tree_ref+0xbb/0x480 [btrfs] btrfs_alloc_tree_block+0x2bf/0x360 [btrfs] alloc_tree_block_no_bg_flush+0x4f/0x60 [btrfs] __btrfs_cow_block+0x12d/0x5f0 [btrfs] btrfs_cow_block+0xf7/0x220 [btrfs] btrfs_search_slot+0x62a/0xc40 [btrfs] btrfs_del_orphan_item+0x65/0xd0 [btrfs] btrfs_find_orphan_roots+0x1bf/0x200 [btrfs] open_ctree+0x125a/0x18a0 [btrfs] btrfs_mount_root.cold+0x13/0xed [btrfs] legacy_get_tree+0x30/0x60 vfs_get_tree+0x28/0xe0 fc_mount+0xe/0x40 vfs_kern_mount.part.0+0x71/0x90 INFO: Freed in __btrfs_run_delayed_refs+0x1117/0x1290 [btrfs] age=3141 cpu=6 pid=1729803 kmem_cache_free+0x34c/0x3c0 __btrfs_run_delayed_refs+0x1117/0x1290 [btrfs] btrfs_run_delayed_refs+0x81/0x210 [btrfs] btrfs_write_dirty_block_groups+0x17d/0x3d0 [btrfs] commit_cowonly_roots+0x248/0x300 [btrfs] btrfs_commit_transaction+0x367/0xc40 [btrfs] close_ctree+0x113/0x2fa [btrfs] generic_shutdown_super+0x6c/0x100 kill_anon_super+0x14/0x30 btrfs_kill_super+0x12/0x20 [btrfs] deactivate_locked_super+0x31/0x70 cleanup_mnt+0x100/0x160 task_work_run+0x68/0xb0 exit_to_user_mode_prepare+0x1bb/0x1c0 syscall_exit_to_user_mode+0x4b/0x260 entry_SYSCALL_64_after_hwframe+0x44/0xa9 kmem_cache_destroy btrfs_delayed_ref_head: Slab cache still has objects CPU: 5 PID: 1729921 Comm: rmmod Tainted: G B W 5.10.0-rc4-btrfs-next-73 #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014 Call Trace: dump_stack+0x8d/0xb5 kmem_cache_destroy+0x119/0x120 btrfs_delayed_ref_exit+0x11/0x35 [btrfs] exit_btrfs_fs+0xa/0x59 [btrfs] __x64_sys_delete_module+0x194/0x260 ? fpregs_assert_state_consistent+0x1e/0x40 ? exit_to_user_mode_prepare+0x55/0x1c0 ? trace_hardirqs_on+0x1b/0xf0 do_syscall_64+0x33/0x80 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7f693e305897 Code: 73 01 c3 48 8b 0d f9 f5 0b (...) RSP: 002b:00007ffcf73eb508 EFLAGS: 00000206 ORIG_RAX: 00000000000000b0 RAX: ffffffffffffffda RBX: 0000559df504f760 RCX: 00007f693e305897 RDX: 000000000000000a RSI: 0000000000000800 RDI: 0000559df504f7c8 RBP: 00007ffcf73eb568 R08: 0000000000000000 R09: 0000000000000000 R10: 00007f693e378ac0 R11: 0000000000000206 R12: 00007ffcf73eb740 R13: 00007ffcf73ec5a6 R14: 0000559df504f2a0 R15: 0000559df504f760 ============================================================================= BUG btrfs_delayed_tree_ref (Tainted: G B W ): Objects remaining in btrfs_delayed_tree_ref on __kmem_cache_shutdown() ----------------------------------------------------------------------------- INFO: Slab 0x0000000011f78dc0 objects=37 used=2 fp=0x0000000032d55d91 flags=0x17fffc000010200 CPU: 3 PID: 1729921 Comm: rmmod Tainted: G B W 5.10.0-rc4-btrfs-next-73 #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014 Call Trace: dump_stack+0x8d/0xb5 slab_err+0xb7/0xdc ? lock_acquired+0x199/0x490 __kmem_cache_shutdown+0x1ac/0x3c0 ? lock_release+0x20e/0x4c0 kmem_cache_destroy+0x55/0x120 btrfs_delayed_ref_exit+0x1d/0x35 [btrfs] exit_btrfs_fs+0xa/0x59 [btrfs] __x64_sys_delete_module+0x194/0x260 ? fpregs_assert_state_consistent+0x1e/0x40 ? exit_to_user_mode_prepare+0x55/0x1c0 ? trace_hardirqs_on+0x1b/0xf0 do_syscall_64+0x33/0x80 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7f693e305897 Code: 73 01 c3 48 8b 0d f9 f5 (...) RSP: 002b:00007ffcf73eb508 EFLAGS: 00000206 ORIG_RAX: 00000000000000b0 RAX: ffffffffffffffda RBX: 0000559df504f760 RCX: 00007f693e305897 RDX: 000000000000000a RSI: 0000000000000800 RDI: 0000559df504f7c8 RBP: 00007ffcf73eb568 R08: 0000000000000000 R09: 0000000000000000 R10: 00007f693e378ac0 R11: 0000000000000206 R12: 00007ffcf73eb740 R13: 00007ffcf73ec5a6 R14: 0000559df504f2a0 R15: 0000559df504f760 INFO: Object 0x000000001a340018 @offset=4408 INFO: Allocated in btrfs_add_delayed_tree_ref+0x9e/0x480 [btrfs] age=1917 cpu=6 pid=1729873 __slab_alloc.isra.0+0x109/0x1c0 kmem_cache_alloc+0x7bb/0x830 btrfs_add_delayed_tree_ref+0x9e/0x480 [btrfs] btrfs_free_tree_block+0x128/0x360 [btrfs] __btrfs_cow_block+0x489/0x5f0 [btrfs] btrfs_cow_block+0xf7/0x220 [btrfs] btrfs_search_slot+0x62a/0xc40 [btrfs] btrfs_del_orphan_item+0x65/0xd0 [btrfs] btrfs_find_orphan_roots+0x1bf/0x200 [btrfs] open_ctree+0x125a/0x18a0 [btrfs] btrfs_mount_root.cold+0x13/0xed [btrfs] legacy_get_tree+0x30/0x60 vfs_get_tree+0x28/0xe0 fc_mount+0xe/0x40 vfs_kern_mount.part.0+0x71/0x90 btrfs_mount+0x13b/0x3e0 [btrfs] INFO: Freed in __btrfs_run_delayed_refs+0x63d/0x1290 [btrfs] age=4167 cpu=4 pid=1729795 kmem_cache_free+0x34c/0x3c0 __btrfs_run_delayed_refs+0x63d/0x1290 [btrfs] btrfs_run_delayed_refs+0x81/0x210 [btrfs] btrfs_commit_transaction+0x60/0xc40 [btrfs] create_subvol+0x56a/0x990 [btrfs] btrfs_mksubvol+0x3fb/0x4a0 [btrfs] __btrfs_ioctl_snap_create+0x119/0x1a0 [btrfs] btrfs_ioctl_snap_create+0x58/0x80 [btrfs] btrfs_ioctl+0x1a92/0x36f0 [btrfs] __x64_sys_ioctl+0x83/0xb0 do_syscall_64+0x33/0x80 entry_SYSCALL_64_after_hwframe+0x44/0xa9 INFO: Object 0x000000002b46292a @offset=13648 INFO: Allocated in btrfs_add_delayed_tree_ref+0x9e/0x480 [btrfs] age=1923 cpu=6 pid=1729873 __slab_alloc.isra.0+0x109/0x1c0 kmem_cache_alloc+0x7bb/0x830 btrfs_add_delayed_tree_ref+0x9e/0x480 [btrfs] btrfs_alloc_tree_block+0x2bf/0x360 [btrfs] alloc_tree_block_no_bg_flush+0x4f/0x60 [btrfs] __btrfs_cow_block+0x12d/0x5f0 [btrfs] btrfs_cow_block+0xf7/0x220 [btrfs] btrfs_search_slot+0x62a/0xc40 [btrfs] btrfs_del_orphan_item+0x65/0xd0 [btrfs] btrfs_find_orphan_roots+0x1bf/0x200 [btrfs] open_ctree+0x125a/0x18a0 [btrfs] btrfs_mount_root.cold+0x13/0xed [btrfs] legacy_get_tree+0x30/0x60 vfs_get_tree+0x28/0xe0 fc_mount+0xe/0x40 vfs_kern_mount.part.0+0x71/0x90 INFO: Freed in __btrfs_run_delayed_refs+0x63d/0x1290 [btrfs] age=3164 cpu=6 pid=1729803 kmem_cache_free+0x34c/0x3c0 __btrfs_run_delayed_refs+0x63d/0x1290 [btrfs] btrfs_run_delayed_refs+0x81/0x210 [btrfs] commit_cowonly_roots+0xfb/0x300 [btrfs] btrfs_commit_transaction+0x367/0xc40 [btrfs] close_ctree+0x113/0x2fa [btrfs] generic_shutdown_super+0x6c/0x100 kill_anon_super+0x14/0x30 btrfs_kill_super+0x12/0x20 [btrfs] deactivate_locked_super+0x31/0x70 cleanup_mnt+0x100/0x160 task_work_run+0x68/0xb0 exit_to_user_mode_prepare+0x1bb/0x1c0 syscall_exit_to_user_mode+0x4b/0x260 entry_SYSCALL_64_after_hwframe+0x44/0xa9 kmem_cache_destroy btrfs_delayed_tree_ref: Slab cache still has objects CPU: 5 PID: 1729921 Comm: rmmod Tainted: G B W 5.10.0-rc4-btrfs-next-73 #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014 Call Trace: dump_stack+0x8d/0xb5 kmem_cache_destroy+0x119/0x120 btrfs_delayed_ref_exit+0x1d/0x35 [btrfs] exit_btrfs_fs+0xa/0x59 [btrfs] __x64_sys_delete_module+0x194/0x260 ? fpregs_assert_state_consistent+0x1e/0x40 ? exit_to_user_mode_prepare+0x55/0x1c0 ? trace_hardirqs_on+0x1b/0xf0 do_syscall_64+0x33/0x80 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7f693e305897 Code: 73 01 c3 48 8b 0d f9 f5 (...) RSP: 002b:00007ffcf73eb508 EFLAGS: 00000206 ORIG_RAX: 00000000000000b0 RAX: ffffffffffffffda RBX: 0000559df504f760 RCX: 00007f693e305897 RDX: 000000000000000a RSI: 0000000000000800 RDI: 0000559df504f7c8 RBP: 00007ffcf73eb568 R08: 0000000000000000 R09: 0000000000000000 R10: 00007f693e378ac0 R11: 0000000000000206 R12: 00007ffcf73eb740 R13: 00007ffcf73ec5a6 R14: 0000559df504f2a0 R15: 0000559df504f760 ============================================================================= BUG btrfs_delayed_extent_op (Tainted: G B W ): Objects remaining in btrfs_delayed_extent_op on __kmem_cache_shutdown() ----------------------------------------------------------------------------- INFO: Slab 0x00000000f145ce2f objects=22 used=1 fp=0x00000000af0f92cf flags=0x17fffc000010200 CPU: 5 PID: 1729921 Comm: rmmod Tainted: G B W 5.10.0-rc4-btrfs-next-73 #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014 Call Trace: dump_stack+0x8d/0xb5 slab_err+0xb7/0xdc ? lock_acquired+0x199/0x490 __kmem_cache_shutdown+0x1ac/0x3c0 ? __mutex_unlock_slowpath+0x45/0x2a0 kmem_cache_destroy+0x55/0x120 exit_btrfs_fs+0xa/0x59 [btrfs] __x64_sys_delete_module+0x194/0x260 ? fpregs_assert_state_consistent+0x1e/0x40 ? exit_to_user_mode_prepare+0x55/0x1c0 ? trace_hardirqs_on+0x1b/0xf0 do_syscall_64+0x33/0x80 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7f693e305897 Code: 73 01 c3 48 8b 0d f9 f5 (...) RSP: 002b:00007ffcf73eb508 EFLAGS: 00000206 ORIG_RAX: 00000000000000b0 RAX: ffffffffffffffda RBX: 0000559df504f760 RCX: 00007f693e305897 RDX: 000000000000000a RSI: 0000000000000800 RDI: 0000559df504f7c8 RBP: 00007ffcf73eb568 R08: 0000000000000000 R09: 0000000000000000 R10: 00007f693e378ac0 R11: 0000000000000206 R12: 00007ffcf73eb740 R13: 00007ffcf73ec5a6 R14: 0000559df504f2a0 R15: 0000559df504f760 INFO: Object 0x000000004cf95ea8 @offset=6264 INFO: Allocated in btrfs_alloc_tree_block+0x1e0/0x360 [btrfs] age=1931 cpu=6 pid=1729873 __slab_alloc.isra.0+0x109/0x1c0 kmem_cache_alloc+0x7bb/0x830 btrfs_alloc_tree_block+0x1e0/0x360 [btrfs] alloc_tree_block_no_bg_flush+0x4f/0x60 [btrfs] __btrfs_cow_block+0x12d/0x5f0 [btrfs] btrfs_cow_block+0xf7/0x220 [btrfs] btrfs_search_slot+0x62a/0xc40 [btrfs] btrfs_del_orphan_item+0x65/0xd0 [btrfs] btrfs_find_orphan_roots+0x1bf/0x200 [btrfs] open_ctree+0x125a/0x18a0 [btrfs] btrfs_mount_root.cold+0x13/0xed [btrfs] legacy_get_tree+0x30/0x60 vfs_get_tree+0x28/0xe0 fc_mount+0xe/0x40 vfs_kern_mount.part.0+0x71/0x90 btrfs_mount+0x13b/0x3e0 [btrfs] INFO: Freed in __btrfs_run_delayed_refs+0xabd/0x1290 [btrfs] age=3173 cpu=6 pid=1729803 kmem_cache_free+0x34c/0x3c0 __btrfs_run_delayed_refs+0xabd/0x1290 [btrfs] btrfs_run_delayed_refs+0x81/0x210 [btrfs] commit_cowonly_roots+0xfb/0x300 [btrfs] btrfs_commit_transaction+0x367/0xc40 [btrfs] close_ctree+0x113/0x2fa [btrfs] generic_shutdown_super+0x6c/0x100 kill_anon_super+0x14/0x30 btrfs_kill_super+0x12/0x20 [btrfs] deactivate_locked_super+0x31/0x70 cleanup_mnt+0x100/0x160 task_work_run+0x68/0xb0 exit_to_user_mode_prepare+0x1bb/0x1c0 syscall_exit_to_user_mode+0x4b/0x260 entry_SYSCALL_64_after_hwframe+0x44/0xa9 kmem_cache_destroy btrfs_delayed_extent_op: Slab cache still has objects CPU: 3 PID: 1729921 Comm: rmmod Tainted: G B W 5.10.0-rc4-btrfs-next-73 #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014 Call Trace: dump_stack+0x8d/0xb5 kmem_cache_destroy+0x119/0x120 exit_btrfs_fs+0xa/0x59 [btrfs] __x64_sys_delete_module+0x194/0x260 ? fpregs_assert_state_consistent+0x1e/0x40 ? exit_to_user_mode_prepare+0x55/0x1c0 ? trace_hardirqs_on+0x1b/0xf0 do_syscall_64+0x33/0x80 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7f693e305897 Code: 73 01 c3 48 8b 0d f9 (...) RSP: 002b:00007ffcf73eb508 EFLAGS: 00000206 ORIG_RAX: 00000000000000b0 RAX: ffffffffffffffda RBX: 0000559df504f760 RCX: 00007f693e305897 RDX: 000000000000000a RSI: 0000000000000800 RDI: 0000559df504f7c8 RBP: 00007ffcf73eb568 R08: 0000000000000000 R09: 0000000000000000 R10: 00007f693e378ac0 R11: 0000000000000206 R12: 00007ffcf73eb740 R13: 00007ffcf73ec5a6 R14: 0000559df504f2a0 R15: 0000559df504f760 BTRFS: state leak: start 30408704 end 30425087 state 1 in tree 1 refs 1 Fix this issue by having the remount path stop the qgroup rescan worker when we are remounting RO and teach the rescan worker to stop when a remount is in progress. If later a remount in RW mode happens, we are already resuming the qgroup rescan worker through the call to btrfs_qgroup_rescan_resume(), so we do not need to worry about that. Tested-by: Fabian Vogt <fvogt@suse.com> Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-01-19cifs: fix interrupted close commandsPaulo Alcantara
[ Upstream commit 2659d3bff3e1b000f49907d0839178b101a89887 ] Retry close command if it gets interrupted to not leak open handles on the server. Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz> Reported-by: Duncan Findlay <duncf@duncf.ca> Suggested-by: Pavel Shilovsky <pshilov@microsoft.com> Fixes: 6988a619f5b7 ("cifs: allow syscalls to be restarted in __smb_send_rqst()") Cc: stable@vger.kernel.org Reviewd-by: Pavel Shilovsky <pshilov@microsoft.com> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-01-19smb3: remove unused flag passed into close functionsSteve French
[ Upstream commit 9e8fae2597405ab1deac8909928eb8e99876f639 ] close was relayered to allow passing in an async flag which is no longer needed in this path. Remove the unneeded parameter "flags" passed in on close. Signed-off-by: Steve French <stfrench@microsoft.com> Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com> Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-01-19ext4: don't leak old mountpoint samplesTheodore Ts'o
[ Upstream commit 5a3b590d4b2db187faa6f06adc9a53d6199fb1f9 ] When the first file is opened, ext4 samples the mountpoint of the filesystem in 64 bytes of the super block. It does so using strlcpy(), this means that the remaining bytes in the super block string buffer are untouched. If the mount point before had a longer path than the current one, it can be reconstructed. Consider the case where the fs was mounted to "/media/johnjdeveloper" and later to "/". The super block buffer then contains "/\x00edia/johnjdeveloper". This case was seen in the wild and caused confusion how the name of a developer ands up on the super block of a filesystem used in production... Fix this by using strncpy() instead of strlcpy(). The superblock field is defined to be a fixed-size char array, and it is already marked using __nonstring in fs/ext4/ext4.h. The consumer of the field in e2fsprogs already assumes that in the case of a 64+ byte mount path, that s_last_mounted will not be NUL terminated. Link: https://lore.kernel.org/r/X9ujIOJG/HqMr88R@mit.edu Reported-by: Richard Weinberger <richard@nod.at> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@kernel.org Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-01-19ext4: fix bug for rename with RENAME_WHITEOUTyangerkun
[ Upstream commit 6b4b8e6b4ad8553660421d6360678b3811d5deb9 ] We got a "deleted inode referenced" warning cross our fsstress test. The bug can be reproduced easily with following steps: cd /dev/shm mkdir test/ fallocate -l 128M img mkfs.ext4 -b 1024 img mount img test/ dd if=/dev/zero of=test/foo bs=1M count=128 mkdir test/dir/ && cd test/dir/ for ((i=0;i<1000;i++)); do touch file$i; done # consume all block cd ~ && renameat2(AT_FDCWD, /dev/shm/test/dir/file1, AT_FDCWD, /dev/shm/test/dir/dst_file, RENAME_WHITEOUT) # ext4_add_entry in ext4_rename will return ENOSPC!! cd /dev/shm/ && umount test/ && mount img test/ && ls -li test/dir/file1 We will get the output: "ls: cannot access 'test/dir/file1': Structure needs cleaning" and the dmesg show: "EXT4-fs error (device loop0): ext4_lookup:1626: inode #2049: comm ls: deleted inode referenced: 139" ext4_rename will create a special inode for whiteout and use this 'ino' to replace the source file's dir entry 'ino'. Once error happens latter(the error above was the ENOSPC return from ext4_add_entry in ext4_rename since all space has been consumed), the cleanup do drop the nlink for whiteout, but forget to restore 'ino' with source file. This will trigger the bug describle as above. Signed-off-by: yangerkun <yangerkun@huawei.com> Reviewed-by: Jan Kara <jack@suse.cz> Cc: stable@vger.kernel.org Fixes: cd808deced43 ("ext4: support RENAME_WHITEOUT") Link: https://lore.kernel.org/r/20210105062857.3566-1-yangerkun@huawei.com Signed-off-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-01-19btrfs: tree-checker: check if chunk item end overflowsSu Yue
[ Upstream commit 347fb0cfc9bab5195c6701e62eda488310d7938f ] While mounting a crafted image provided by user, kernel panics due to the invalid chunk item whose end is less than start. [66.387422] loop: module loaded [66.389773] loop0: detected capacity change from 262144 to 0 [66.427708] BTRFS: device fsid a62e00e8-e94e-4200-8217-12444de93c2e devid 1 transid 12 /dev/loop0 scanned by mount (613) [66.431061] BTRFS info (device loop0): disk space caching is enabled [66.431078] BTRFS info (device loop0): has skinny extents [66.437101] BTRFS error: insert state: end < start 29360127 37748736 [66.437136] ------------[ cut here ]------------ [66.437140] WARNING: CPU: 16 PID: 613 at fs/btrfs/extent_io.c:557 insert_state.cold+0x1a/0x46 [btrfs] [66.437369] CPU: 16 PID: 613 Comm: mount Tainted: G O 5.11.0-rc1-custom #45 [66.437374] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ArchLinux 1.14.0-1 04/01/2014 [66.437378] RIP: 0010:insert_state.cold+0x1a/0x46 [btrfs] [66.437420] RSP: 0018:ffff93e5414c3908 EFLAGS: 00010286 [66.437427] RAX: 0000000000000000 RBX: 0000000001bfffff RCX: 0000000000000000 [66.437431] RDX: 0000000000000000 RSI: ffffffffb90d4660 RDI: 00000000ffffffff [66.437434] RBP: ffff93e5414c3938 R08: 0000000000000001 R09: 0000000000000001 [66.437438] R10: ffff93e5414c3658 R11: 0000000000000000 R12: ffff8ec782d72aa0 [66.437441] R13: ffff8ec78bc71628 R14: 0000000000000000 R15: 0000000002400000 [66.437447] FS: 00007f01386a8580(0000) GS:ffff8ec809000000(0000) knlGS:0000000000000000 [66.437451] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [66.437455] CR2: 00007f01382fa000 CR3: 0000000109a34000 CR4: 0000000000750ee0 [66.437460] PKRU: 55555554 [66.437464] Call Trace: [66.437475] set_extent_bit+0x652/0x740 [btrfs] [66.437539] set_extent_bits_nowait+0x1d/0x20 [btrfs] [66.437576] add_extent_mapping+0x1e0/0x2f0 [btrfs] [66.437621] read_one_chunk+0x33c/0x420 [btrfs] [66.437674] btrfs_read_chunk_tree+0x6a4/0x870 [btrfs] [66.437708] ? kvm_sched_clock_read+0x18/0x40 [66.437739] open_ctree+0xb32/0x1734 [btrfs] [66.437781] ? bdi_register_va+0x1b/0x20 [66.437788] ? super_setup_bdi_name+0x79/0xd0 [66.437810] btrfs_mount_root.cold+0x12/0xeb [btrfs] [66.437854] ? __kmalloc_track_caller+0x217/0x3b0 [66.437873] legacy_get_tree+0x34/0x60 [66.437880] vfs_get_tree+0x2d/0xc0 [66.437888] vfs_kern_mount.part.0+0x78/0xc0 [66.437897] vfs_kern_mount+0x13/0x20 [66.437902] btrfs_mount+0x11f/0x3c0 [btrfs] [66.437940] ? kfree+0x5ff/0x670 [66.437944] ? __kmalloc_track_caller+0x217/0x3b0 [66.437962] legacy_get_tree+0x34/0x60 [66.437974] vfs_get_tree+0x2d/0xc0 [66.437983] path_mount+0x48c/0xd30 [66.437998] __x64_sys_mount+0x108/0x140 [66.438011] do_syscall_64+0x38/0x50 [66.438018] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [66.438023] RIP: 0033:0x7f0138827f6e [66.438033] RSP: 002b:00007ffecd79edf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 [66.438040] RAX: ffffffffffffffda RBX: 00007f013894c264 RCX: 00007f0138827f6e [66.438044] RDX: 00005593a4a41360 RSI: 00005593a4a33690 RDI: 00005593a4a3a6c0 [66.438047] RBP: 00005593a4a33440 R08: 0000000000000000 R09: 0000000000000001 [66.438050] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 [66.438054] R13: 00005593a4a3a6c0 R14: 00005593a4a41360 R15: 00005593a4a33440 [66.438078] irq event stamp: 18169 [66.438082] hardirqs last enabled at (18175): [<ffffffffb81154bf>] console_unlock+0x4ff/0x5f0 [66.438088] hardirqs last disabled at (18180): [<ffffffffb8115427>] console_unlock+0x467/0x5f0 [66.438092] softirqs last enabled at (16910): [<ffffffffb8a00fe2>] asm_call_irq_on_stack+0x12/0x20 [66.438097] softirqs last disabled at (16905): [<ffffffffb8a00fe2>] asm_call_irq_on_stack+0x12/0x20 [66.438103] ---[ end trace e114b111db64298b ]--- [66.438107] BTRFS error: found node 12582912 29360127 on insert of 37748736 29360127 [66.438127] BTRFS critical: panic in extent_io_tree_panic:679: locking error: extent tree was modified by another thread while locked (errno=-17 Object already exists) [66.441069] ------------[ cut here ]------------ [66.441072] kernel BUG at fs/btrfs/extent_io.c:679! [66.442064] invalid opcode: 0000 [#1] PREEMPT SMP NOPTI [66.443018] CPU: 16 PID: 613 Comm: mount Tainted: G W O 5.11.0-rc1-custom #45 [66.444538] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ArchLinux 1.14.0-1 04/01/2014 [66.446223] RIP: 0010:extent_io_tree_panic.isra.0+0x23/0x25 [btrfs] [66.450878] RSP: 0018:ffff93e5414c3948 EFLAGS: 00010246 [66.451840] RAX: 0000000000000000 RBX: 0000000001bfffff RCX: 0000000000000000 [66.453141] RDX: 0000000000000000 RSI: ffffffffb90d4660 RDI: 00000000ffffffff [66.454445] RBP: ffff93e5414c3948 R08: 0000000000000001 R09: 0000000000000001 [66.455743] R10: ffff93e5414c3658 R11: 0000000000000000 R12: ffff8ec782d728c0 [66.457055] R13: ffff8ec78bc71628 R14: ffff8ec782d72aa0 R15: 0000000002400000 [66.458356] FS: 00007f01386a8580(0000) GS:ffff8ec809000000(0000) knlGS:0000000000000000 [66.459841] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [66.460895] CR2: 00007f01382fa000 CR3: 0000000109a34000 CR4: 0000000000750ee0 [66.462196] PKRU: 55555554 [66.462692] Call Trace: [66.463139] set_extent_bit.cold+0x30/0x98 [btrfs] [66.464049] set_extent_bits_nowait+0x1d/0x20 [btrfs] [66.490466] add_extent_mapping+0x1e0/0x2f0 [btrfs] [66.514097] read_one_chunk+0x33c/0x420 [btrfs] [66.534976] btrfs_read_chunk_tree+0x6a4/0x870 [btrfs] [66.555718] ? kvm_sched_clock_read+0x18/0x40 [66.575758] open_ctree+0xb32/0x1734 [btrfs] [66.595272] ? bdi_register_va+0x1b/0x20 [66.614638] ? super_setup_bdi_name+0x79/0xd0 [66.633809] btrfs_mount_root.cold+0x12/0xeb [btrfs] [66.652938] ? __kmalloc_track_caller+0x217/0x3b0 [66.671925] legacy_get_tree+0x34/0x60 [66.690300] vfs_get_tree+0x2d/0xc0 [66.708221] vfs_kern_mount.part.0+0x78/0xc0 [66.725808] vfs_kern_mount+0x13/0x20 [66.742730] btrfs_mount+0x11f/0x3c0 [btrfs] [66.759350] ? kfree+0x5ff/0x670 [66.775441] ? __kmalloc_track_caller+0x217/0x3b0 [66.791750] legacy_get_tree+0x34/0x60 [66.807494] vfs_get_tree+0x2d/0xc0 [66.823349] path_mount+0x48c/0xd30 [66.838753] __x64_sys_mount+0x108/0x140 [66.854412] do_syscall_64+0x38/0x50 [66.869673] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [66.885093] RIP: 0033:0x7f0138827f6e [66.945613] RSP: 002b:00007ffecd79edf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 [66.977214] RAX: ffffffffffffffda RBX: 00007f013894c264 RCX: 00007f0138827f6e [66.994266] RDX: 00005593a4a41360 RSI: 00005593a4a33690 RDI: 00005593a4a3a6c0 [67.011544] RBP: 00005593a4a33440 R08: 0000000000000000 R09: 0000000000000001 [67.028836] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 [67.045812] R13: 00005593a4a3a6c0 R14: 00005593a4a41360 R15: 00005593a4a33440 [67.216138] ---[ end trace e114b111db64298c ]--- [67.237089] RIP: 0010:extent_io_tree_panic.isra.0+0x23/0x25 [btrfs] [67.325317] RSP: 0018:ffff93e5414c3948 EFLAGS: 00010246 [67.347946] RAX: 0000000000000000 RBX: 0000000001bfffff RCX: 0000000000000000 [67.371343] RDX: 0000000000000000 RSI: ffffffffb90d4660 RDI: 00000000ffffffff [67.394757] RBP: ffff93e5414c3948 R08: 0000000000000001 R09: 0000000000000001 [67.418409] R10: ffff93e5414c3658 R11: 0000000000000000 R12: ffff8ec782d728c0 [67.441906] R13: ffff8ec78bc71628 R14: ffff8ec782d72aa0 R15: 0000000002400000 [67.465436] FS: 00007f01386a8580(0000) GS:ffff8ec809000000(0000) knlGS:0000000000000000 [67.511660] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [67.535047] CR2: 00007f01382fa000 CR3: 0000000109a34000 CR4: 0000000000750ee0 [67.558449] PKRU: 55555554 [67.581146] note: mount[613] exited with preempt_count 2 The image has a chunk item which has a logical start 37748736 and length 18446744073701163008 (-8M). The calculated end 29360127 overflows. EEXIST was caught by insert_state() because of the duplicate end and extent_io_tree_panic() was called. Add overflow check of chunk item end to tree checker so it can be detected early at mount time. Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=208929 CC: stable@vger.kernel.org # 4.19+ Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: Su Yue <l@damenly.su> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-01-19btrfs: prevent NULL pointer dereference in extent_io_tree_panicSu Yue
commit 29b665cc51e8b602bf2a275734349494776e3dbc upstream. Some extent io trees are initialized with NULL private member (e.g. btrfs_device::alloc_state and btrfs_fs_info::excluded_extents). Dereference of a NULL tree->private as inode pointer will cause panic. Pass tree->fs_info as it's known to be valid in all cases. Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=208929 Fixes: 05912a3c04eb ("btrfs: drop extent_io_ops::tree_fs_info callback") CC: stable@vger.kernel.org # 4.19+ Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: Su Yue <l@damenly.su> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-12btrfs: send: fix wrong file path when there is an inode with a pending rmdirFilipe Manana
commit 0b3f407e6728d990ae1630a02c7b952c21c288d3 upstream. When doing an incremental send, if we have a new inode that happens to have the same number that an old directory inode had in the base snapshot and that old directory has a pending rmdir operation, we end up computing a wrong path for the new inode, causing the receiver to fail. Example reproducer: $ cat test-send-rmdir.sh #!/bin/bash DEV=/dev/sdi MNT=/mnt/sdi mkfs.btrfs -f $DEV >/dev/null mount $DEV $MNT mkdir $MNT/dir touch $MNT/dir/file1 touch $MNT/dir/file2 touch $MNT/dir/file3 # Filesystem looks like: # # . (ino 256) # |----- dir/ (ino 257) # |----- file1 (ino 258) # |----- file2 (ino 259) # |----- file3 (ino 260) # btrfs subvolume snapshot -r $MNT $MNT/snap1 btrfs send -f /tmp/snap1.send $MNT/snap1 # Now remove our directory and all its files. rm -fr $MNT/dir # Unmount the filesystem and mount it again. This is to ensure that # the next inode that is created ends up with the same inode number # that our directory "dir" had, 257, which is the first free "objectid" # available after mounting again the filesystem. umount $MNT mount $DEV $MNT # Now create a new file (it could be a directory as well). touch $MNT/newfile # Filesystem now looks like: # # . (ino 256) # |----- newfile (ino 257) # btrfs subvolume snapshot -r $MNT $MNT/snap2 btrfs send -f /tmp/snap2.send -p $MNT/snap1 $MNT/snap2 # Now unmount the filesystem, create a new one, mount it and try to apply # both send streams to recreate both snapshots. umount $DEV mkfs.btrfs -f $DEV >/dev/null mount $DEV $MNT btrfs receive -f /tmp/snap1.send $MNT btrfs receive -f /tmp/snap2.send $MNT umount $MNT When running the test, the receive operation for the incremental stream fails: $ ./test-send-rmdir.sh Create a readonly snapshot of '/mnt/sdi' in '/mnt/sdi/snap1' At subvol /mnt/sdi/snap1 Create a readonly snapshot of '/mnt/sdi' in '/mnt/sdi/snap2' At subvol /mnt/sdi/snap2 At subvol snap1 At snapshot snap2 ERROR: chown o257-9-0 failed: No such file or directory So fix this by tracking directories that have a pending rmdir by inode number and generation number, instead of only inode number. A test case for fstests follows soon. Reported-by: Massimo B. <massimo.b@gmx.net> Tested-by: Massimo B. <massimo.b@gmx.net> Link: https://lore.kernel.org/linux-btrfs/6ae34776e85912960a253a8327068a892998e685.camel@gmx.net/ CC: stable@vger.kernel.org # 4.19+ Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-12proc: fix lookup in /proc/net subdirectories after setns(2)Alexey Dobriyan
[ Upstream commit c6c75deda81344c3a95d1d1f606d5cee109e5d54 ] Commit 1fde6f21d90f ("proc: fix /proc/net/* after setns(2)") only forced revalidation of regular files under /proc/net/ However, /proc/net/ is unusual in the sense of /proc/net/foo handlers take netns pointer from parent directory which is old netns. Steps to reproduce: (void)open("/proc/net/sctp/snmp", O_RDONLY); unshare(CLONE_NEWNET); int fd = open("/proc/net/sctp/snmp", O_RDONLY); read(fd, &c, 1); Read will read wrong data from original netns. Patch forces lookup on every directory under /proc/net . Link: https://lkml.kernel.org/r/20201205160916.GA109739@localhost.localdomain Fixes: 1da4d377f943 ("proc: revalidate misc dentries") Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Reported-by: "Rantala, Tommi T. (Nokia - FI/Espoo)" <tommi.t.rantala@nokia.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-01-12proc: change ->nlink under proc_subdir_lockAlexey Dobriyan
[ Upstream commit e06689bf57017ac022ccf0f2a5071f760821ce0f ] Currently gluing PDE into global /proc tree is done under lock, but changing ->nlink is not. Additionally struct proc_dir_entry::nlink is not atomic so updates can be lost. Link: http://lkml.kernel.org/r/20190925202436.GA17388@avx2 Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-01-09exec: Transform exec_update_mutex into a rw_semaphoreEric W. Biederman
[ Upstream commit f7cfd871ae0c5008d94b6f66834e7845caa93c15 ] Recently syzbot reported[0] that there is a deadlock amongst the users of exec_update_mutex. The problematic lock ordering found by lockdep was: perf_event_open (exec_update_mutex -> ovl_i_mutex) chown (ovl_i_mutex -> sb_writes) sendfile (sb_writes -> p->lock) by reading from a proc file and writing to overlayfs proc_pid_syscall (p->lock -> exec_update_mutex) While looking at possible solutions it occured to me that all of the users and possible users involved only wanted to state of the given process to remain the same. They are all readers. The only writer is exec. There is no reason for readers to block on each other. So fix this deadlock by transforming exec_update_mutex into a rw_semaphore named exec_update_lock that only exec takes for writing. Cc: Jann Horn <jannh@google.com> Cc: Vasiliy Kulikov <segoon@openwall.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Bernd Edlinger <bernd.edlinger@hotmail.de> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Christopher Yeoh <cyeoh@au1.ibm.com> Cc: Cyrill Gorcunov <gorcunov@gmail.com> Cc: Sargun Dhillon <sargun@sargun.me> Cc: Christian Brauner <christian.brauner@ubuntu.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Fixes: eea9673250db ("exec: Add exec_update_mutex to replace cred_guard_mutex") [0] https://lkml.kernel.org/r/00000000000063640c05ade8e3de@google.com Reported-by: syzbot+db9cdf3dd1f64252c6ef@syzkaller.appspotmail.com Link: https://lkml.kernel.org/r/87ft4mbqen.fsf@x220.int.ebiederm.org Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-01-09fuse: fix bad inodeMiklos Szeredi
[ Upstream commit 5d069dbe8aaf2a197142558b6fb2978189ba3454 ] Jan Kara's analysis of the syzbot report (edited): The reproducer opens a directory on FUSE filesystem, it then attaches dnotify mark to the open directory. After that a fuse_do_getattr() call finds that attributes returned by the server are inconsistent, and calls make_bad_inode() which, among other things does: inode->i_mode = S_IFREG; This then confuses dnotify which doesn't tear down its structures properly and eventually crashes. Avoid calling make_bad_inode() on a live inode: switch to a private flag on the fuse inode. Also add the test to ops which the bad_inode_ops would have caught. This bug goes back to the initial merge of fuse in 2.6.14... Reported-by: syzbot+f427adf9324b92652ccc@syzkaller.appspotmail.com Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Tested-by: Jan Kara <jack@suse.cz> Cc: <stable@vger.kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-01-06fs/namespace.c: WARN if mnt_count has become negativeEric Biggers
[ Upstream commit edf7ddbf1c5eb98b720b063b73e20e8a4a1ce673 ] Missing calls to mntget() (or equivalently, too many calls to mntput()) are hard to detect because mntput() delays freeing mounts using task_work_add(), then again using call_rcu(). As a result, mnt_count can often be decremented to -1 without getting a KASAN use-after-free report. Such cases are still bugs though, and they point to real use-after-frees being possible. For an example of this, see the bug fixed by commit 1b0b9cc8d379 ("vfs: fsmount: add missing mntget()"), discussed at https://lkml.kernel.org/linux-fsdevel/20190605135401.GB30925@xxxxxxxxxxxxxxxxxxxxxxxxx/T/#u. This bug *should* have been trivial to find. But actually, it wasn't found until syzkaller happened to use fchdir() to manipulate the reference count just right for the bug to be noticeable. Address this by making mntput_no_expire() issue a WARN if mnt_count has become negative. Suggested-by: Miklos Szeredi <miklos@szeredi.hu> Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Sasha Levin <sashal@kernel.org>