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2023-12-13nilfs2: fix missing error check for sb_set_blocksize callRyusuke Konishi
commit d61d0ab573649789bf9eb909c89a1a193b2e3d10 upstream. When mounting a filesystem image with a block size larger than the page size, nilfs2 repeatedly outputs long error messages with stack traces to the kernel log, such as the following: getblk(): invalid block size 8192 requested logical block size: 512 ... Call Trace: dump_stack_lvl+0x92/0xd4 dump_stack+0xd/0x10 bdev_getblk+0x33a/0x354 __breadahead+0x11/0x80 nilfs_search_super_root+0xe2/0x704 [nilfs2] load_nilfs+0x72/0x504 [nilfs2] nilfs_mount+0x30f/0x518 [nilfs2] legacy_get_tree+0x1b/0x40 vfs_get_tree+0x18/0xc4 path_mount+0x786/0xa88 __ia32_sys_mount+0x147/0x1a8 __do_fast_syscall_32+0x56/0xc8 do_fast_syscall_32+0x29/0x58 do_SYSENTER_32+0x15/0x18 entry_SYSENTER_32+0x98/0xf1 ... This overloads the system logger. And to make matters worse, it sometimes crashes the kernel with a memory access violation. This is because the return value of the sb_set_blocksize() call, which should be checked for errors, is not checked. The latter issue is due to out-of-buffer memory being accessed based on a large block size that caused sb_set_blocksize() to fail for buffers read with the initial minimum block size that remained unupdated in the super_block structure. Since nilfs2 mkfs tool does not accept block sizes larger than the system page size, this has been overlooked. However, it is possible to create this situation by intentionally modifying the tool or by passing a filesystem image created on a system with a large page size to a system with a smaller page size and mounting it. Fix this issue by inserting the expected error handling for the call to sb_set_blocksize(). Link: https://lkml.kernel.org/r/20231129141547.4726-1-konishi.ryusuke@gmail.com Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-12-13nilfs2: prevent WARNING in nilfs_sufile_set_segment_usage()Ryusuke Konishi
commit 675abf8df1353e0e3bde314993e0796c524cfbf0 upstream. If nilfs2 reads a disk image with corrupted segment usage metadata, and its segment usage information is marked as an error for the segment at the write location, nilfs_sufile_set_segment_usage() can trigger WARN_ONs during log writing. Segments newly allocated for writing with nilfs_sufile_alloc() will not have this error flag set, but this unexpected situation will occur if the segment indexed by either nilfs->ns_segnum or nilfs->ns_nextnum (active segment) was marked in error. Fix this issue by inserting a sanity check to treat it as a file system corruption. Since error returns are not allowed during the execution phase where nilfs_sufile_set_segment_usage() is used, this inserts the sanity check into nilfs_sufile_mark_dirty() which pre-reads the buffer containing the segment usage record to be updated and sets it up in a dirty state for writing. In addition, nilfs_sufile_set_segment_usage() is also called when canceling log writing and undoing segment usage update, so in order to avoid issuing the same kernel warning in that case, in case of cancellation, avoid checking the error flag in nilfs_sufile_set_segment_usage(). Link: https://lkml.kernel.org/r/20231205085947.4431-1-konishi.ryusuke@gmail.com Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> Reported-by: syzbot+14e9f834f6ddecece094@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=14e9f834f6ddecece094 Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-10-10nilfs2: fix potential use after free in nilfs_gccache_submit_read_data()Pan Bian
commit 7ee29facd8a9c5a26079148e36bcf07141b3a6bc upstream. In nilfs_gccache_submit_read_data(), brelse(bh) is called to drop the reference count of bh when the call to nilfs_dat_translate() fails. If the reference count hits 0 and its owner page gets unlocked, bh may be freed. However, bh->b_page is dereferenced to put the page after that, which may result in a use-after-free bug. This patch moves the release operation after unlocking and putting the page. NOTE: The function in question is only called in GC, and in combination with current userland tools, address translation using DAT does not occur in that function, so the code path that causes this issue will not be executed. However, it is possible to run that code path by intentionally modifying the userland GC library or by calling the GC ioctl directly. [konishi.ryusuke@gmail.com: NOTE added to the commit log] Link: https://lkml.kernel.org/r/1543201709-53191-1-git-send-email-bianpan2016@163.com Link: https://lkml.kernel.org/r/20230921141731.10073-1-konishi.ryusuke@gmail.com Fixes: a3d93f709e89 ("nilfs2: block cache for garbage collection") Signed-off-by: Pan Bian <bianpan2016@163.com> Reported-by: Ferry Meng <mengferry@linux.alibaba.com> Closes: https://lkml.kernel.org/r/20230818092022.111054-1-mengferry@linux.alibaba.com Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-09-23nilfs2: fix WARNING in mark_buffer_dirty due to discarded buffer reuseRyusuke Konishi
commit cdaac8e7e5a059f9b5e816cda257f08d0abffacd upstream. A syzbot stress test using a corrupted disk image reported that mark_buffer_dirty() called from __nilfs_mark_inode_dirty() or nilfs_palloc_commit_alloc_entry() may output a kernel warning, and can panic if the kernel is booted with panic_on_warn. This is because nilfs2 keeps buffer pointers in local structures for some metadata and reuses them, but such buffers may be forcibly discarded by nilfs_clear_dirty_page() in some critical situations. This issue is reported to appear after commit 28a65b49eb53 ("nilfs2: do not write dirty data after degenerating to read-only"), but the issue has potentially existed before. Fix this issue by checking the uptodate flag when attempting to reuse an internally held buffer, and reloading the metadata instead of reusing the buffer if the flag was lost. Link: https://lkml.kernel.org/r/20230818131804.7758-1-konishi.ryusuke@gmail.com Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> Reported-by: syzbot+cdfcae656bac88ba0e2d@syzkaller.appspotmail.com Closes: https://lkml.kernel.org/r/0000000000003da75f05fdeffd12@google.com Fixes: 8c26c4e2694a ("nilfs2: fix issue with flush kernel thread after remount in RO mode because of driver's internal error or metadata corruption") Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> Cc: <stable@vger.kernel.org> # 3.10+ Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-09-23nilfs2: fix general protection fault in nilfs_lookup_dirty_data_buffers()Ryusuke Konishi
commit f83913f8c5b882a312e72b7669762f8a5c9385e4 upstream. A syzbot stress test reported that create_empty_buffers() called from nilfs_lookup_dirty_data_buffers() can cause a general protection fault. Analysis using its reproducer revealed that the back reference "mapping" from a page/folio has been changed to NULL after dirty page/folio gang lookup in nilfs_lookup_dirty_data_buffers(). Fix this issue by excluding pages/folios from being collected if, after acquiring a lock on each page/folio, its back reference "mapping" differs from the pointer to the address space struct that held the page/folio. Link: https://lkml.kernel.org/r/20230805132038.6435-1-konishi.ryusuke@gmail.com Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> Reported-by: syzbot+0ad741797f4565e7e2d2@syzkaller.appspotmail.com Closes: https://lkml.kernel.org/r/0000000000002930a705fc32b231@google.com Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-08-16nilfs2: fix use-after-free of nilfs_root in dirtying inodes via iputRyusuke Konishi
commit f8654743a0e6909dc634cbfad6db6816f10f3399 upstream. During unmount process of nilfs2, nothing holds nilfs_root structure after nilfs2 detaches its writer in nilfs_detach_log_writer(). Previously, nilfs_evict_inode() could cause use-after-free read for nilfs_root if inodes are left in "garbage_list" and released by nilfs_dispose_list at the end of nilfs_detach_log_writer(), and this bug was fixed by commit 9b5a04ac3ad9 ("nilfs2: fix use-after-free bug of nilfs_root in nilfs_evict_inode()"). However, it turned out that there is another possibility of UAF in the call path where mark_inode_dirty_sync() is called from iput(): nilfs_detach_log_writer() nilfs_dispose_list() iput() mark_inode_dirty_sync() __mark_inode_dirty() nilfs_dirty_inode() __nilfs_mark_inode_dirty() nilfs_load_inode_block() --> causes UAF of nilfs_root struct This can happen after commit 0ae45f63d4ef ("vfs: add support for a lazytime mount option"), which changed iput() to call mark_inode_dirty_sync() on its final reference if i_state has I_DIRTY_TIME flag and i_nlink is non-zero. This issue appears after commit 28a65b49eb53 ("nilfs2: do not write dirty data after degenerating to read-only") when using the syzbot reproducer, but the issue has potentially existed before. Fix this issue by adding a "purging flag" to the nilfs structure, setting that flag while disposing the "garbage_list" and checking it in __nilfs_mark_inode_dirty(). Unlike commit 9b5a04ac3ad9 ("nilfs2: fix use-after-free bug of nilfs_root in nilfs_evict_inode()"), this patch does not rely on ns_writer to determine whether to skip operations, so as not to break recovery on mount. The nilfs_salvage_orphan_logs routine dirties the buffer of salvaged data before attaching the log writer, so changing __nilfs_mark_inode_dirty() to skip the operation when ns_writer is NULL will cause recovery write to fail. The purpose of using the cleanup-only flag is to allow for narrowing of such conditions. Link: https://lkml.kernel.org/r/20230728191318.33047-1-konishi.ryusuke@gmail.com Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> Reported-by: syzbot+74db8b3087f293d3a13a@syzkaller.appspotmail.com Closes: https://lkml.kernel.org/r/000000000000b4e906060113fd63@google.com Fixes: 0ae45f63d4ef ("vfs: add support for a lazytime mount option") Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> Cc: <stable@vger.kernel.org> # 4.0+ Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-06-28nilfs2: prevent general protection fault in nilfs_clear_dirty_page()Ryusuke Konishi
commit 782e53d0c14420858dbf0f8f797973c150d3b6d7 upstream. In a syzbot stress test that deliberately causes file system errors on nilfs2 with a corrupted disk image, it has been reported that nilfs_clear_dirty_page() called from nilfs_clear_dirty_pages() can cause a general protection fault. In nilfs_clear_dirty_pages(), when looking up dirty pages from the page cache and calling nilfs_clear_dirty_page() for each dirty page/folio retrieved, the back reference from the argument page to "mapping" may have been changed to NULL (and possibly others). It is necessary to check this after locking the page/folio. So, fix this issue by not calling nilfs_clear_dirty_page() on a page/folio after locking it in nilfs_clear_dirty_pages() if the back reference "mapping" from the page/folio is different from the "mapping" that held the page/folio just before. Link: https://lkml.kernel.org/r/20230612021456.3682-1-konishi.ryusuke@gmail.com Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> Reported-by: syzbot+53369d11851d8f26735c@syzkaller.appspotmail.com Closes: https://lkml.kernel.org/r/000000000000da4f6b05eb9bf593@google.com Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-06-28nilfs2: fix buffer corruption due to concurrent device readsRyusuke Konishi
commit 679bd7ebdd315bf457a4740b306ae99f1d0a403d upstream. As a result of analysis of a syzbot report, it turned out that in three cases where nilfs2 allocates block device buffers directly via sb_getblk, concurrent reads to the device can corrupt the allocated buffers. Nilfs2 uses sb_getblk for segment summary blocks, that make up a log header, and the super root block, that is the trailer, and when moving and writing the second super block after fs resize. In any of these, since the uptodate flag is not set when storing metadata to be written in the allocated buffers, the stored metadata will be overwritten if a device read of the same block occurs concurrently before the write. This causes metadata corruption and misbehavior in the log write itself, causing warnings in nilfs_btree_assign() as reported. Fix these issues by setting an uptodate flag on the buffer head on the first or before modifying each buffer obtained with sb_getblk, and clearing the flag on failure. When setting the uptodate flag, the lock_buffer/unlock_buffer pair is used to perform necessary exclusive control, and the buffer is filled to ensure that uninitialized bytes are not mixed into the data read from others. As for buffers for segment summary blocks, they are filled incrementally, so if the uptodate flag was unset on their allocation, set the flag and zero fill the buffer once at that point. Also, regarding the superblock move routine, the starting point of the memset call to zerofill the block is incorrectly specified, which can cause a buffer overflow on file systems with block sizes greater than 4KiB. In addition, if the superblock is moved within a large block, it is necessary to assume the possibility that the data in the superblock will be destroyed by zero-filling before copying. So fix these potential issues as well. Link: https://lkml.kernel.org/r/20230609035732.20426-1-konishi.ryusuke@gmail.com Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> Reported-by: syzbot+31837fe952932efc8fb9@syzkaller.appspotmail.com Closes: https://lkml.kernel.org/r/00000000000030000a05e981f475@google.com Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-06-28nilfs2: reject devices with insufficient block countRyusuke Konishi
commit 92c5d1b860e9581d64baca76779576c0ab0d943d upstream. The current sanity check for nilfs2 geometry information lacks checks for the number of segments stored in superblocks, so even for device images that have been destructively truncated or have an unusually high number of segments, the mount operation may succeed. This causes out-of-bounds block I/O on file system block reads or log writes to the segments, the latter in particular causing "a_ops->writepages" to repeatedly fail, resulting in sync_inodes_sb() to hang. Fix this issue by checking the number of segments stored in the superblock and avoiding mounting devices that can cause out-of-bounds accesses. To eliminate the possibility of overflow when calculating the number of blocks required for the device from the number of segments, this also adds a helper function to calculate the upper bound on the number of segments and inserts a check using it. Link: https://lkml.kernel.org/r/20230526021332.3431-1-konishi.ryusuke@gmail.com Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> Reported-by: syzbot+7d50f1e54a12ba3aeae2@syzkaller.appspotmail.com Link: https://syzkaller.appspot.com/bug?extid=7d50f1e54a12ba3aeae2 Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-06-21nilfs2: fix possible out-of-bounds segment allocation in resize ioctlRyusuke Konishi
commit fee5eaecca86afa544355569b831c1f90f334b85 upstream. Syzbot reports that in its stress test for resize ioctl, the log writing function nilfs_segctor_do_construct hits a WARN_ON in nilfs_segctor_truncate_segments(). It turned out that there is a problem with the current implementation of the resize ioctl, which changes the writable range on the device (the range of allocatable segments) at the end of the resize process. This order is necessary for file system expansion to avoid corrupting the superblock at trailing edge. However, in the case of a file system shrink, if log writes occur after truncating out-of-bounds trailing segments and before the resize is complete, segments may be allocated from the truncated space. The userspace resize tool was fine as it limits the range of allocatable segments before performing the resize, but it can run into this issue if the resize ioctl is called alone. Fix this issue by changing nilfs_sufile_resize() to update the range of allocatable segments immediately after successful truncation of segment space in case of file system shrink. Link: https://lkml.kernel.org/r/20230524094348.3784-1-konishi.ryusuke@gmail.com Fixes: 4e33f9eab07e ("nilfs2: implement resize ioctl") Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> Reported-by: syzbot+33494cd0df2ec2931851@syzkaller.appspotmail.com Closes: https://lkml.kernel.org/r/0000000000005434c405fbbafdc5@google.com Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-06-21nilfs2: fix incomplete buffer cleanup in nilfs_btnode_abort_change_key()Ryusuke Konishi
commit 2f012f2baca140c488e43d27a374029c1e59098d upstream. A syzbot fault injection test reported that nilfs_btnode_create_block, a helper function that allocates a new node block for b-trees, causes a kernel BUG for disk images where the file system block size is smaller than the page size. This was due to unexpected flags on the newly allocated buffer head, and it turned out to be because the buffer flags were not cleared by nilfs_btnode_abort_change_key() after an error occurred during a b-tree update operation and the buffer was later reused in that state. Fix this issue by using nilfs_btnode_delete() to abandon the unused preallocated buffer in nilfs_btnode_abort_change_key(). Link: https://lkml.kernel.org/r/20230513102428.10223-1-konishi.ryusuke@gmail.com Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> Reported-by: syzbot+b0a35a5c1f7e846d3b09@syzkaller.appspotmail.com Closes: https://lkml.kernel.org/r/000000000000d1d6c205ebc4d512@google.com Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-05-30nilfs2: fix use-after-free bug of nilfs_root in nilfs_evict_inode()Ryusuke Konishi
commit 9b5a04ac3ad9898c4745cba46ea26de74ba56a8e upstream. During unmount process of nilfs2, nothing holds nilfs_root structure after nilfs2 detaches its writer in nilfs_detach_log_writer(). However, since nilfs_evict_inode() uses nilfs_root for some cleanup operations, it may cause use-after-free read if inodes are left in "garbage_list" and released by nilfs_dispose_list() at the end of nilfs_detach_log_writer(). Fix this issue by modifying nilfs_evict_inode() to only clear inode without additional metadata changes that use nilfs_root if the file system is degraded to read-only or the writer is detached. Link: https://lkml.kernel.org/r/20230509152956.8313-1-konishi.ryusuke@gmail.com Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> Reported-by: syzbot+78d4495558999f55d1da@syzkaller.appspotmail.com Closes: https://lkml.kernel.org/r/00000000000099e5ac05fb1c3b85@google.com Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-05-17nilfs2: fix infinite loop in nilfs_mdt_get_block()Ryusuke Konishi
commit a6a491c048882e7e424d407d32cba0b52d9ef2bf upstream. If the disk image that nilfs2 mounts is corrupted and a virtual block address obtained by block lookup for a metadata file is invalid, nilfs_bmap_lookup_at_level() may return the same internal return code as -ENOENT, meaning the block does not exist in the metadata file. This duplication of return codes confuses nilfs_mdt_get_block(), causing it to read and create a metadata block indefinitely. In particular, if this happens to the inode metadata file, ifile, semaphore i_rwsem can be left held, causing task hangs in lock_mount. Fix this issue by making nilfs_bmap_lookup_at_level() treat virtual block address translation failures with -ENOENT as metadata corruption instead of returning the error code. Link: https://lkml.kernel.org/r/20230430193046.6769-1-konishi.ryusuke@gmail.com Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> Reported-by: syzbot+221d75710bde87fa0e97@syzkaller.appspotmail.com Link: https://syzkaller.appspot.com/bug?extid=221d75710bde87fa0e97 Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-05-17nilfs2: do not write dirty data after degenerating to read-onlyRyusuke Konishi
commit 28a65b49eb53e172d23567005465019658bfdb4d upstream. According to syzbot's report, mark_buffer_dirty() called from nilfs_segctor_do_construct() outputs a warning with some patterns after nilfs2 detects metadata corruption and degrades to read-only mode. After such read-only degeneration, page cache data may be cleared through nilfs_clear_dirty_page() which may also clear the uptodate flag for their buffer heads. However, even after the degeneration, log writes are still performed by unmount processing etc., which causes mark_buffer_dirty() to be called for buffer heads without the "uptodate" flag and causes the warning. Since any writes should not be done to a read-only file system in the first place, this fixes the warning in mark_buffer_dirty() by letting nilfs_segctor_do_construct() abort early if in read-only mode. This also changes the retry check of nilfs_segctor_write_out() to avoid unnecessary log write retries if it detects -EROFS that nilfs_segctor_do_construct() returned. Link: https://lkml.kernel.org/r/20230427011526.13457-1-konishi.ryusuke@gmail.com Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> Reported-by: syzbot+2af3bc9585be7f23f290@syzkaller.appspotmail.com Link: https://syzkaller.appspot.com/bug?extid=2af3bc9585be7f23f290 Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-04-26nilfs2: initialize unused bytes in segment summary blocksRyusuke Konishi
commit ef832747a82dfbc22a3702219cc716f449b24e4a upstream. Syzbot still reports uninit-value in nilfs_add_checksums_on_logs() for KMSAN enabled kernels after applying commit 7397031622e0 ("nilfs2: initialize "struct nilfs_binfo_dat"->bi_pad field"). This is because the unused bytes at the end of each block in segment summaries are not initialized. So this fixes the issue by padding the unused bytes with null bytes. Link: https://lkml.kernel.org/r/20230417173513.12598-1-konishi.ryusuke@gmail.com Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> Reported-by: syzbot+048585f3f4227bb2b49b@syzkaller.appspotmail.com Link: https://syzkaller.appspot.com/bug?extid=048585f3f4227bb2b49b Cc: Alexander Potapenko <glider@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-04-20nilfs2: fix sysfs interface lifetimeRyusuke Konishi
commit 42560f9c92cc43dce75dbf06cc0d840dced39b12 upstream. The current nilfs2 sysfs support has issues with the timing of creation and deletion of sysfs entries, potentially leading to null pointer dereferences, use-after-free, and lockdep warnings. Some of the sysfs attributes for nilfs2 per-filesystem instance refer to metadata file "cpfile", "sufile", or "dat", but nilfs_sysfs_create_device_group that creates those attributes is executed before the inodes for these metadata files are loaded, and nilfs_sysfs_delete_device_group which deletes these sysfs entries is called after releasing their metadata file inodes. Therefore, access to some of these sysfs attributes may occur outside of the lifetime of these metadata files, resulting in inode NULL pointer dereferences or use-after-free. In addition, the call to nilfs_sysfs_create_device_group() is made during the locking period of the semaphore "ns_sem" of nilfs object, so the shrinker call caused by the memory allocation for the sysfs entries, may derive lock dependencies "ns_sem" -> (shrinker) -> "locks acquired in nilfs_evict_inode()". Since nilfs2 may acquire "ns_sem" deep in the call stack holding other locks via its error handler __nilfs_error(), this causes lockdep to report circular locking. This is a false positive and no circular locking actually occurs as no inodes exist yet when nilfs_sysfs_create_device_group() is called. Fortunately, the lockdep warnings can be resolved by simply moving the call to nilfs_sysfs_create_device_group() out of "ns_sem". This fixes these sysfs issues by revising where the device's sysfs interface is created/deleted and keeping its lifetime within the lifetime of the metadata files above. Link: https://lkml.kernel.org/r/20230330205515.6167-1-konishi.ryusuke@gmail.com Fixes: dd70edbde262 ("nilfs2: integrate sysfs support into driver") Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> Reported-by: syzbot+979fa7f9c0d086fdc282@syzkaller.appspotmail.com Link: https://lkml.kernel.org/r/0000000000003414b505f7885f7e@google.com Reported-by: syzbot+5b7d542076d9bddc3c6a@syzkaller.appspotmail.com Link: https://lkml.kernel.org/r/0000000000006ac86605f5f44eb9@google.com Cc: Viacheslav Dubeyko <slava@dubeyko.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-04-20nilfs2: fix potential UAF of struct nilfs_sc_info in nilfs_segctor_thread()Ryusuke Konishi
commit 6be49d100c22ffea3287a4b19d7639d259888e33 upstream. The finalization of nilfs_segctor_thread() can race with nilfs_segctor_kill_thread() which terminates that thread, potentially causing a use-after-free BUG as KASAN detected. At the end of nilfs_segctor_thread(), it assigns NULL to "sc_task" member of "struct nilfs_sc_info" to indicate the thread has finished, and then notifies nilfs_segctor_kill_thread() of this using waitqueue "sc_wait_task" on the struct nilfs_sc_info. However, here, immediately after the NULL assignment to "sc_task", it is possible that nilfs_segctor_kill_thread() will detect it and return to continue the deallocation, freeing the nilfs_sc_info structure before the thread does the notification. This fixes the issue by protecting the NULL assignment to "sc_task" and its notification, with spinlock "sc_state_lock" of the struct nilfs_sc_info. Since nilfs_segctor_kill_thread() does a final check to see if "sc_task" is NULL with "sc_state_lock" locked, this can eliminate the race. Link: https://lkml.kernel.org/r/20230327175318.8060-1-konishi.ryusuke@gmail.com Reported-by: syzbot+b08ebcc22f8f3e6be43a@syzkaller.appspotmail.com Link: https://lkml.kernel.org/r/00000000000000660d05f7dfa877@google.com Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-04-05nilfs2: fix kernel-infoleak in nilfs_ioctl_wrap_copy()Ryusuke Konishi
commit 003587000276f81d0114b5ce773d80c119d8cb30 upstream. The ioctl helper function nilfs_ioctl_wrap_copy(), which exchanges a metadata array to/from user space, may copy uninitialized buffer regions to user space memory for read-only ioctl commands NILFS_IOCTL_GET_SUINFO and NILFS_IOCTL_GET_CPINFO. This can occur when the element size of the user space metadata given by the v_size member of the argument nilfs_argv structure is larger than the size of the metadata element (nilfs_suinfo structure or nilfs_cpinfo structure) on the file system side. KMSAN-enabled kernels detect this issue as follows: BUG: KMSAN: kernel-infoleak in instrument_copy_to_user include/linux/instrumented.h:121 [inline] BUG: KMSAN: kernel-infoleak in _copy_to_user+0xc0/0x100 lib/usercopy.c:33 instrument_copy_to_user include/linux/instrumented.h:121 [inline] _copy_to_user+0xc0/0x100 lib/usercopy.c:33 copy_to_user include/linux/uaccess.h:169 [inline] nilfs_ioctl_wrap_copy+0x6fa/0xc10 fs/nilfs2/ioctl.c:99 nilfs_ioctl_get_info fs/nilfs2/ioctl.c:1173 [inline] nilfs_ioctl+0x2402/0x4450 fs/nilfs2/ioctl.c:1290 nilfs_compat_ioctl+0x1b8/0x200 fs/nilfs2/ioctl.c:1343 __do_compat_sys_ioctl fs/ioctl.c:968 [inline] __se_compat_sys_ioctl+0x7dd/0x1000 fs/ioctl.c:910 __ia32_compat_sys_ioctl+0x93/0xd0 fs/ioctl.c:910 do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline] __do_fast_syscall_32+0xa2/0x100 arch/x86/entry/common.c:178 do_fast_syscall_32+0x37/0x80 arch/x86/entry/common.c:203 do_SYSENTER_32+0x1f/0x30 arch/x86/entry/common.c:246 entry_SYSENTER_compat_after_hwframe+0x70/0x82 Uninit was created at: __alloc_pages+0x9f6/0xe90 mm/page_alloc.c:5572 alloc_pages+0xab0/0xd80 mm/mempolicy.c:2287 __get_free_pages+0x34/0xc0 mm/page_alloc.c:5599 nilfs_ioctl_wrap_copy+0x223/0xc10 fs/nilfs2/ioctl.c:74 nilfs_ioctl_get_info fs/nilfs2/ioctl.c:1173 [inline] nilfs_ioctl+0x2402/0x4450 fs/nilfs2/ioctl.c:1290 nilfs_compat_ioctl+0x1b8/0x200 fs/nilfs2/ioctl.c:1343 __do_compat_sys_ioctl fs/ioctl.c:968 [inline] __se_compat_sys_ioctl+0x7dd/0x1000 fs/ioctl.c:910 __ia32_compat_sys_ioctl+0x93/0xd0 fs/ioctl.c:910 do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline] __do_fast_syscall_32+0xa2/0x100 arch/x86/entry/common.c:178 do_fast_syscall_32+0x37/0x80 arch/x86/entry/common.c:203 do_SYSENTER_32+0x1f/0x30 arch/x86/entry/common.c:246 entry_SYSENTER_compat_after_hwframe+0x70/0x82 Bytes 16-127 of 3968 are uninitialized ... This eliminates the leak issue by initializing the page allocated as buffer using get_zeroed_page(). Link: https://lkml.kernel.org/r/20230307085548.6290-1-konishi.ryusuke@gmail.com Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> Reported-by: syzbot+132fdd2f1e1805fdc591@syzkaller.appspotmail.com Link: https://lkml.kernel.org/r/000000000000a5bd2d05f63f04ae@google.com Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-02-22nilfs2: fix underflow in second superblock position calculationsRyusuke Konishi
commit 99b9402a36f0799f25feee4465bfa4b8dfa74b4d upstream. Macro NILFS_SB2_OFFSET_BYTES, which computes the position of the second superblock, underflows when the argument device size is less than 4096 bytes. Therefore, when using this macro, it is necessary to check in advance that the device size is not less than a lower limit, or at least that underflow does not occur. The current nilfs2 implementation lacks this check, causing out-of-bound block access when mounting devices smaller than 4096 bytes: I/O error, dev loop0, sector 36028797018963960 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2 NILFS (loop0): unable to read secondary superblock (blocksize = 1024) In addition, when trying to resize the filesystem to a size below 4096 bytes, this underflow occurs in nilfs_resize_fs(), passing a huge number of segments to nilfs_sufile_resize(), corrupting parameters such as the number of segments in superblocks. This causes excessive loop iterations in nilfs_sufile_resize() during a subsequent resize ioctl, causing semaphore ns_segctor_sem to block for a long time and hang the writer thread: INFO: task segctord:5067 blocked for more than 143 seconds. Not tainted 6.2.0-rc8-syzkaller-00015-gf6feea56f66d #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:segctord state:D stack:23456 pid:5067 ppid:2 flags:0x00004000 Call Trace: <TASK> context_switch kernel/sched/core.c:5293 [inline] __schedule+0x1409/0x43f0 kernel/sched/core.c:6606 schedule+0xc3/0x190 kernel/sched/core.c:6682 rwsem_down_write_slowpath+0xfcf/0x14a0 kernel/locking/rwsem.c:1190 nilfs_transaction_lock+0x25c/0x4f0 fs/nilfs2/segment.c:357 nilfs_segctor_thread_construct fs/nilfs2/segment.c:2486 [inline] nilfs_segctor_thread+0x52f/0x1140 fs/nilfs2/segment.c:2570 kthread+0x270/0x300 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 </TASK> ... Call Trace: <TASK> folio_mark_accessed+0x51c/0xf00 mm/swap.c:515 __nilfs_get_page_block fs/nilfs2/page.c:42 [inline] nilfs_grab_buffer+0x3d3/0x540 fs/nilfs2/page.c:61 nilfs_mdt_submit_block+0xd7/0x8f0 fs/nilfs2/mdt.c:121 nilfs_mdt_read_block+0xeb/0x430 fs/nilfs2/mdt.c:176 nilfs_mdt_get_block+0x12d/0xbb0 fs/nilfs2/mdt.c:251 nilfs_sufile_get_segment_usage_block fs/nilfs2/sufile.c:92 [inline] nilfs_sufile_truncate_range fs/nilfs2/sufile.c:679 [inline] nilfs_sufile_resize+0x7a3/0x12b0 fs/nilfs2/sufile.c:777 nilfs_resize_fs+0x20c/0xed0 fs/nilfs2/super.c:422 nilfs_ioctl_resize fs/nilfs2/ioctl.c:1033 [inline] nilfs_ioctl+0x137c/0x2440 fs/nilfs2/ioctl.c:1301 ... This fixes these issues by inserting appropriate minimum device size checks or anti-underflow checks, depending on where the macro is used. Link: https://lkml.kernel.org/r/0000000000004e1dfa05f4a48e6b@google.com Link: https://lkml.kernel.org/r/20230214224043.24141-1-konishi.ryusuke@gmail.com Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> Reported-by: <syzbot+f0c4082ce5ebebdac63b@syzkaller.appspotmail.com> Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-24nilfs2: fix general protection fault in nilfs_btree_insert()Ryusuke Konishi
commit 7633355e5c7f29c049a9048e461427d1d8ed3051 upstream. If nilfs2 reads a corrupted disk image and tries to reads a b-tree node block by calling __nilfs_btree_get_block() against an invalid virtual block address, it returns -ENOENT because conversion of the virtual block address to a disk block address fails. However, this return value is the same as the internal code that b-tree lookup routines return to indicate that the block being searched does not exist, so functions that operate on that b-tree may misbehave. When nilfs_btree_insert() receives this spurious 'not found' code from nilfs_btree_do_lookup(), it misunderstands that the 'not found' check was successful and continues the insert operation using incomplete lookup path data, causing the following crash: general protection fault, probably for non-canonical address 0xdffffc0000000005: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000028-0x000000000000002f] ... RIP: 0010:nilfs_btree_get_nonroot_node fs/nilfs2/btree.c:418 [inline] RIP: 0010:nilfs_btree_prepare_insert fs/nilfs2/btree.c:1077 [inline] RIP: 0010:nilfs_btree_insert+0x6d3/0x1c10 fs/nilfs2/btree.c:1238 Code: bc 24 80 00 00 00 4c 89 f8 48 c1 e8 03 42 80 3c 28 00 74 08 4c 89 ff e8 4b 02 92 fe 4d 8b 3f 49 83 c7 28 4c 89 f8 48 c1 e8 03 <42> 80 3c 28 00 74 08 4c 89 ff e8 2e 02 92 fe 4d 8b 3f 49 83 c7 02 ... Call Trace: <TASK> nilfs_bmap_do_insert fs/nilfs2/bmap.c:121 [inline] nilfs_bmap_insert+0x20d/0x360 fs/nilfs2/bmap.c:147 nilfs_get_block+0x414/0x8d0 fs/nilfs2/inode.c:101 __block_write_begin_int+0x54c/0x1a80 fs/buffer.c:1991 __block_write_begin fs/buffer.c:2041 [inline] block_write_begin+0x93/0x1e0 fs/buffer.c:2102 nilfs_write_begin+0x9c/0x110 fs/nilfs2/inode.c:261 generic_perform_write+0x2e4/0x5e0 mm/filemap.c:3772 __generic_file_write_iter+0x176/0x400 mm/filemap.c:3900 generic_file_write_iter+0xab/0x310 mm/filemap.c:3932 call_write_iter include/linux/fs.h:2186 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x7dc/0xc50 fs/read_write.c:584 ksys_write+0x177/0x2a0 fs/read_write.c:637 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd ... </TASK> This patch fixes the root cause of this problem by replacing the error code that __nilfs_btree_get_block() returns on block address conversion failure from -ENOENT to another internal code -EINVAL which means that the b-tree metadata is corrupted. By returning -EINVAL, it propagates without glitches, and for all relevant b-tree operations, functions in the upper bmap layer output an error message indicating corrupted b-tree metadata via nilfs_bmap_convert_error(), and code -EIO will be eventually returned as it should be. Link: https://lkml.kernel.org/r/000000000000bd89e205f0e38355@google.com Link: https://lkml.kernel.org/r/20230105055356.8811-1-konishi.ryusuke@gmail.com Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> Reported-by: syzbot+ede796cecd5296353515@syzkaller.appspotmail.com Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-18nilfs2: fix shift-out-of-bounds/overflow in nilfs_sb2_bad_offset()Ryusuke Konishi
[ Upstream commit 610a2a3d7d8be3537458a378ec69396a76c385b6 ] Patch series "nilfs2: fix UBSAN shift-out-of-bounds warnings on mount time". The first patch fixes a bug reported by syzbot, and the second one fixes the remaining bug of the same kind. Although they are triggered by the same super block data anomaly, I divided it into the above two because the details of the issues and how to fix it are different. Both are required to eliminate the shift-out-of-bounds issues at mount time. This patch (of 2): If the block size exponent information written in an on-disk superblock is corrupted, nilfs_sb2_bad_offset helper function can trigger shift-out-of-bounds warning followed by a kernel panic (if panic_on_warn is set): shift exponent 38983 is too large for 64-bit type 'unsigned long long' Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1b1/0x28e lib/dump_stack.c:106 ubsan_epilogue lib/ubsan.c:151 [inline] __ubsan_handle_shift_out_of_bounds+0x33d/0x3b0 lib/ubsan.c:322 nilfs_sb2_bad_offset fs/nilfs2/the_nilfs.c:449 [inline] nilfs_load_super_block+0xdf5/0xe00 fs/nilfs2/the_nilfs.c:523 init_nilfs+0xb7/0x7d0 fs/nilfs2/the_nilfs.c:577 nilfs_fill_super+0xb1/0x5d0 fs/nilfs2/super.c:1047 nilfs_mount+0x613/0x9b0 fs/nilfs2/super.c:1317 ... In addition, since nilfs_sb2_bad_offset() performs multiplication without considering the upper bound, the computation may overflow if the disk layout parameters are not normal. This fixes these issues by inserting preliminary sanity checks for those parameters and by converting the comparison from one involving multiplication and left bit-shifting to one using division and right bit-shifting. Link: https://lkml.kernel.org/r/20221027044306.42774-1-konishi.ryusuke@gmail.com Link: https://lkml.kernel.org/r/20221027044306.42774-2-konishi.ryusuke@gmail.com Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> Reported-by: syzbot+e91619dd4c11c4960706@syzkaller.appspotmail.com Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-12-08nilfs2: fix NULL pointer dereference in nilfs_palloc_commit_free_entry()ZhangPeng
commit f0a0ccda18d6fd826d7c7e7ad48a6ed61c20f8b4 upstream. Syzbot reported a null-ptr-deref bug: NILFS (loop0): segctord starting. Construction interval = 5 seconds, CP frequency < 30 seconds general protection fault, probably for non-canonical address 0xdffffc0000000002: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017] CPU: 1 PID: 3603 Comm: segctord Not tainted 6.1.0-rc2-syzkaller-00105-gb229b6ca5abb #0 Hardware name: Google Compute Engine/Google Compute Engine, BIOS Google 10/11/2022 RIP: 0010:nilfs_palloc_commit_free_entry+0xe5/0x6b0 fs/nilfs2/alloc.c:608 Code: 00 00 00 00 fc ff df 80 3c 02 00 0f 85 cd 05 00 00 48 b8 00 00 00 00 00 fc ff df 4c 8b 73 08 49 8d 7e 10 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 26 05 00 00 49 8b 46 10 be a6 00 00 00 48 c7 c7 RSP: 0018:ffffc90003dff830 EFLAGS: 00010212 RAX: dffffc0000000000 RBX: ffff88802594e218 RCX: 000000000000000d RDX: 0000000000000002 RSI: 0000000000002000 RDI: 0000000000000010 RBP: ffff888071880222 R08: 0000000000000005 R09: 000000000000003f R10: 000000000000000d R11: 0000000000000000 R12: ffff888071880158 R13: ffff88802594e220 R14: 0000000000000000 R15: 0000000000000004 FS: 0000000000000000(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fb1c08316a8 CR3: 0000000018560000 CR4: 0000000000350ee0 Call Trace: <TASK> nilfs_dat_commit_free fs/nilfs2/dat.c:114 [inline] nilfs_dat_commit_end+0x464/0x5f0 fs/nilfs2/dat.c:193 nilfs_dat_commit_update+0x26/0x40 fs/nilfs2/dat.c:236 nilfs_btree_commit_update_v+0x87/0x4a0 fs/nilfs2/btree.c:1940 nilfs_btree_commit_propagate_v fs/nilfs2/btree.c:2016 [inline] nilfs_btree_propagate_v fs/nilfs2/btree.c:2046 [inline] nilfs_btree_propagate+0xa00/0xd60 fs/nilfs2/btree.c:2088 nilfs_bmap_propagate+0x73/0x170 fs/nilfs2/bmap.c:337 nilfs_collect_file_data+0x45/0xd0 fs/nilfs2/segment.c:568 nilfs_segctor_apply_buffers+0x14a/0x470 fs/nilfs2/segment.c:1018 nilfs_segctor_scan_file+0x3f4/0x6f0 fs/nilfs2/segment.c:1067 nilfs_segctor_collect_blocks fs/nilfs2/segment.c:1197 [inline] nilfs_segctor_collect fs/nilfs2/segment.c:1503 [inline] nilfs_segctor_do_construct+0x12fc/0x6af0 fs/nilfs2/segment.c:2045 nilfs_segctor_construct+0x8e3/0xb30 fs/nilfs2/segment.c:2379 nilfs_segctor_thread_construct fs/nilfs2/segment.c:2487 [inline] nilfs_segctor_thread+0x3c3/0xf30 fs/nilfs2/segment.c:2570 kthread+0x2e4/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 </TASK> ... If DAT metadata file is corrupted on disk, there is a case where req->pr_desc_bh is NULL and blocknr is 0 at nilfs_dat_commit_end() during a b-tree operation that cascadingly updates ancestor nodes of the b-tree, because nilfs_dat_commit_alloc() for a lower level block can initialize the blocknr on the same DAT entry between nilfs_dat_prepare_end() and nilfs_dat_commit_end(). If this happens, nilfs_dat_commit_end() calls nilfs_dat_commit_free() without valid buffer heads in req->pr_desc_bh and req->pr_bitmap_bh, and causes the NULL pointer dereference above in nilfs_palloc_commit_free_entry() function, which leads to a crash. Fix this by adding a NULL check on req->pr_desc_bh and req->pr_bitmap_bh before nilfs_palloc_commit_free_entry() in nilfs_dat_commit_free(). This also calls nilfs_error() in that case to notify that there is a fatal flaw in the filesystem metadata and prevent further operations. Link: https://lkml.kernel.org/r/00000000000097c20205ebaea3d6@google.com Link: https://lkml.kernel.org/r/20221114040441.1649940-1-zhangpeng362@huawei.com Link: https://lkml.kernel.org/r/20221119120542.17204-1-konishi.ryusuke@gmail.com Signed-off-by: ZhangPeng <zhangpeng362@huawei.com> Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> Reported-by: syzbot+ebe05ee8e98f755f61d0@syzkaller.appspotmail.com Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-12-08nilfs2: fix nilfs_sufile_mark_dirty() not set segment usage as dirtyChen Zhongjin
commit 512c5ca01a3610ab14ff6309db363de51f1c13a6 upstream. When extending segments, nilfs_sufile_alloc() is called to get an unassigned segment, then mark it as dirty to avoid accidentally allocating the same segment in the future. But for some special cases such as a corrupted image it can be unreliable. If such corruption of the dirty state of the segment occurs, nilfs2 may reallocate a segment that is in use and pick the same segment for writing twice at the same time. This will cause the problem reported by syzkaller: https://syzkaller.appspot.com/bug?id=c7c4748e11ffcc367cef04f76e02e931833cbd24 This case started with segbuf1.segnum = 3, nextnum = 4 when constructed. It supposed segment 4 has already been allocated and marked as dirty. However the dirty state was corrupted and segment 4 usage was not dirty. For the first time nilfs_segctor_extend_segments() segment 4 was allocated again, which made segbuf2 and next segbuf3 had same segment 4. sb_getblk() will get same bh for segbuf2 and segbuf3, and this bh is added to both buffer lists of two segbuf. It makes the lists broken which causes NULL pointer dereference. Fix the problem by setting usage as dirty every time in nilfs_sufile_mark_dirty(), which is called during constructing current segment to be written out and before allocating next segment. [chenzhongjin@huawei.com: add lock protection per Ryusuke] Link: https://lkml.kernel.org/r/20221121091141.214703-1-chenzhongjin@huawei.com Link: https://lkml.kernel.org/r/20221118063304.140187-1-chenzhongjin@huawei.com Fixes: 9ff05123e3bf ("nilfs2: segment constructor") Signed-off-by: Chen Zhongjin <chenzhongjin@huawei.com> Reported-by: <syzbot+77e4f0...@syzkaller.appspotmail.com> Reported-by: Liu Shixin <liushixin2@huawei.com> Acked-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-11-25nilfs2: fix use-after-free bug of ns_writer on remountRyusuke Konishi
commit 8cccf05fe857a18ee26e20d11a8455a73ffd4efd upstream. If a nilfs2 filesystem is downgraded to read-only due to metadata corruption on disk and is remounted read/write, or if emergency read-only remount is performed, detaching a log writer and synchronizing the filesystem can be done at the same time. In these cases, use-after-free of the log writer (hereinafter nilfs->ns_writer) can happen as shown in the scenario below: Task1 Task2 -------------------------------- ------------------------------ nilfs_construct_segment nilfs_segctor_sync init_wait init_waitqueue_entry add_wait_queue schedule nilfs_remount (R/W remount case) nilfs_attach_log_writer nilfs_detach_log_writer nilfs_segctor_destroy kfree finish_wait _raw_spin_lock_irqsave __raw_spin_lock_irqsave do_raw_spin_lock debug_spin_lock_before <-- use-after-free While Task1 is sleeping, nilfs->ns_writer is freed by Task2. After Task1 waked up, Task1 accesses nilfs->ns_writer which is already freed. This scenario diagram is based on the Shigeru Yoshida's post [1]. This patch fixes the issue by not detaching nilfs->ns_writer on remount so that this UAF race doesn't happen. Along with this change, this patch also inserts a few necessary read-only checks with superblock instance where only the ns_writer pointer was used to check if the filesystem is read-only. Link: https://syzkaller.appspot.com/bug?id=79a4c002e960419ca173d55e863bd09e8112df8b Link: https://lkml.kernel.org/r/20221103141759.1836312-1-syoshida@redhat.com [1] Link: https://lkml.kernel.org/r/20221104142959.28296-1-konishi.ryusuke@gmail.com Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> Reported-by: syzbot+f816fa82f8783f7a02bb@syzkaller.appspotmail.com Reported-by: Shigeru Yoshida <syoshida@redhat.com> Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-11-25nilfs2: fix deadlock in nilfs_count_free_blocks()Ryusuke Konishi
commit 8ac932a4921a96ca52f61935dbba64ea87bbd5dc upstream. A semaphore deadlock can occur if nilfs_get_block() detects metadata corruption while locating data blocks and a superblock writeback occurs at the same time: task 1 task 2 ------ ------ * A file operation * nilfs_truncate() nilfs_get_block() down_read(rwsem A) <-- nilfs_bmap_lookup_contig() ... generic_shutdown_super() nilfs_put_super() * Prepare to write superblock * down_write(rwsem B) <-- nilfs_cleanup_super() * Detect b-tree corruption * nilfs_set_log_cursor() nilfs_bmap_convert_error() nilfs_count_free_blocks() __nilfs_error() down_read(rwsem A) <-- nilfs_set_error() down_write(rwsem B) <-- *** DEADLOCK *** Here, nilfs_get_block() readlocks rwsem A (= NILFS_MDT(dat_inode)->mi_sem) and then calls nilfs_bmap_lookup_contig(), but if it fails due to metadata corruption, __nilfs_error() is called from nilfs_bmap_convert_error() inside the lock section. Since __nilfs_error() calls nilfs_set_error() unless the filesystem is read-only and nilfs_set_error() attempts to writelock rwsem B (= nilfs->ns_sem) to write back superblock exclusively, hierarchical lock acquisition occurs in the order rwsem A -> rwsem B. Now, if another task starts updating the superblock, it may writelock rwsem B during the lock sequence above, and can deadlock trying to readlock rwsem A in nilfs_count_free_blocks(). However, there is actually no need to take rwsem A in nilfs_count_free_blocks() because it, within the lock section, only reads a single integer data on a shared struct with nilfs_sufile_get_ncleansegs(). This has been the case after commit aa474a220180 ("nilfs2: add local variable to cache the number of clean segments"), that is, even before this bug was introduced. So, this resolves the deadlock problem by just not taking the semaphore in nilfs_count_free_blocks(). Link: https://lkml.kernel.org/r/20221029044912.9139-1-konishi.ryusuke@gmail.com Fixes: e828949e5b42 ("nilfs2: call nilfs_error inside bmap routines") Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> Reported-by: syzbot+45d6ce7b7ad7ef455d03@syzkaller.appspotmail.com Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> Cc: <stable@vger.kernel.org> [2.6.38+ Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-10-26nilfs2: fix use-after-free bug of struct nilfs_rootRyusuke Konishi
commit d325dc6eb763c10f591c239550b8c7e5466a5d09 upstream. If the beginning of the inode bitmap area is corrupted on disk, an inode with the same inode number as the root inode can be allocated and fail soon after. In this case, the subsequent call to nilfs_clear_inode() on that bogus root inode will wrongly decrement the reference counter of struct nilfs_root, and this will erroneously free struct nilfs_root, causing kernel oopses. This fixes the problem by changing nilfs_new_inode() to skip reserved inode numbers while repairing the inode bitmap. Link: https://lkml.kernel.org/r/20221003150519.39789-1-konishi.ryusuke@gmail.com Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> Reported-by: syzbot+b8c672b0e22615c80fe0@syzkaller.appspotmail.com Reported-by: Khalid Masum <khalid.masum.92@gmail.com> Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-10-26nilfs2: replace WARN_ONs by nilfs_error for checkpoint acquisition failureRyusuke Konishi
commit 723ac751208f6d6540191689cfbf6c77135a7a1b upstream. If creation or finalization of a checkpoint fails due to anomalies in the checkpoint metadata on disk, a kernel warning is generated. This patch replaces the WARN_ONs by nilfs_error, so that a kernel, booted with panic_on_warn, does not panic. A nilfs_error is appropriate here to handle the abnormal filesystem condition. This also replaces the detected error codes with an I/O error so that neither of the internal error codes is returned to callers. Link: https://lkml.kernel.org/r/20220929123330.19658-1-konishi.ryusuke@gmail.com Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> Reported-by: syzbot+fbb3e0b24e8dae5a16ee@syzkaller.appspotmail.com Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-10-26nilfs2: fix leak of nilfs_root in case of writer thread creation failureRyusuke Konishi
commit d0d51a97063db4704a5ef6bc978dddab1636a306 upstream. If nilfs_attach_log_writer() failed to create a log writer thread, it frees a data structure of the log writer without any cleanup. After commit e912a5b66837 ("nilfs2: use root object to get ifile"), this causes a leak of struct nilfs_root, which started to leak an ifile metadata inode and a kobject on that struct. In addition, if the kernel is booted with panic_on_warn, the above ifile metadata inode leak will cause the following panic when the nilfs2 kernel module is removed: kmem_cache_destroy nilfs2_inode_cache: Slab cache still has objects when called from nilfs_destroy_cachep+0x16/0x3a [nilfs2] WARNING: CPU: 8 PID: 1464 at mm/slab_common.c:494 kmem_cache_destroy+0x138/0x140 ... RIP: 0010:kmem_cache_destroy+0x138/0x140 Code: 00 20 00 00 e8 a9 55 d8 ff e9 76 ff ff ff 48 8b 53 60 48 c7 c6 20 70 65 86 48 c7 c7 d8 69 9c 86 48 8b 4c 24 28 e8 ef 71 c7 00 <0f> 0b e9 53 ff ff ff c3 48 81 ff ff 0f 00 00 77 03 31 c0 c3 53 48 ... Call Trace: <TASK> ? nilfs_palloc_freev.cold.24+0x58/0x58 [nilfs2] nilfs_destroy_cachep+0x16/0x3a [nilfs2] exit_nilfs_fs+0xa/0x1b [nilfs2] __x64_sys_delete_module+0x1d9/0x3a0 ? __sanitizer_cov_trace_pc+0x1a/0x50 ? syscall_trace_enter.isra.19+0x119/0x190 do_syscall_64+0x34/0x80 entry_SYSCALL_64_after_hwframe+0x63/0xcd ... </TASK> Kernel panic - not syncing: panic_on_warn set ... This patch fixes these issues by calling nilfs_detach_log_writer() cleanup function if spawning the log writer thread fails. Link: https://lkml.kernel.org/r/20221007085226.57667-1-konishi.ryusuke@gmail.com Fixes: e912a5b66837 ("nilfs2: use root object to get ifile") Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> Reported-by: syzbot+7381dc4ad60658ca4c05@syzkaller.appspotmail.com Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-10-26nilfs2: fix NULL pointer dereference at nilfs_bmap_lookup_at_level()Ryusuke Konishi
commit 21a87d88c2253350e115029f14fe2a10a7e6c856 upstream. If the i_mode field in inode of metadata files is corrupted on disk, it can cause the initialization of bmap structure, which should have been called from nilfs_read_inode_common(), not to be called. This causes a lockdep warning followed by a NULL pointer dereference at nilfs_bmap_lookup_at_level(). This patch fixes these issues by adding a missing sanitiy check for the i_mode field of metadata file's inode. Link: https://lkml.kernel.org/r/20221002030804.29978-1-konishi.ryusuke@gmail.com Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> Reported-by: syzbot+2b32eb36c1a825b7a74c@syzkaller.appspotmail.com Reported-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-07-21nilfs2: fix incorrect masking of permission flags for symlinksRyusuke Konishi
commit 5924e6ec1585445f251ea92713eb15beb732622a upstream. The permission flags of newly created symlinks are wrongly dropped on nilfs2 with the current umask value even though symlinks should have 777 (rwxrwxrwx) permissions: $ umask 0022 $ touch file && ln -s file symlink; ls -l file symlink -rw-r--r--. 1 root root 0 Jun 23 16:29 file lrwxr-xr-x. 1 root root 4 Jun 23 16:29 symlink -> file This fixes the bug by inserting a missing check that excludes symlinks. Link: https://lkml.kernel.org/r/1655974441-5612-1-git-send-email-konishi.ryusuke@gmail.com Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> Reported-by: Tommy Pettersson <ptp@lysator.liu.se> Reported-by: Ciprian Craciun <ciprian.craciun@gmail.com> Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-05-25nilfs2: fix lockdep warnings during disk space reclamationRyusuke Konishi
[ Upstream commit 6e211930f79aa45d422009a5f2e5467d2369ffe5 ] During disk space reclamation, nilfs2 still emits the following lockdep warning due to page/folio operations on shadowed page caches that nilfs2 uses to get a snapshot of DAT file in memory: WARNING: CPU: 0 PID: 2643 at include/linux/backing-dev.h:272 __folio_mark_dirty+0x645/0x670 ... RIP: 0010:__folio_mark_dirty+0x645/0x670 ... Call Trace: filemap_dirty_folio+0x74/0xd0 __set_page_dirty_nobuffers+0x85/0xb0 nilfs_copy_dirty_pages+0x288/0x510 [nilfs2] nilfs_mdt_save_to_shadow_map+0x50/0xe0 [nilfs2] nilfs_clean_segments+0xee/0x5d0 [nilfs2] nilfs_ioctl_clean_segments.isra.19+0xb08/0xf40 [nilfs2] nilfs_ioctl+0xc52/0xfb0 [nilfs2] __x64_sys_ioctl+0x11d/0x170 This fixes the remaining warning by using inode objects to hold those page caches. Link: https://lkml.kernel.org/r/1647867427-30498-3-git-send-email-konishi.ryusuke@gmail.com Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: David Hildenbrand <david@redhat.com> Cc: Hao Sun <sunhao.th@gmail.com> 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>
2022-05-25nilfs2: fix lockdep warnings in page operations for btree nodesRyusuke Konishi
[ Upstream commit e897be17a441fa637cd166fc3de1445131e57692 ] Patch series "nilfs2 lockdep warning fixes". The first two are to resolve the lockdep warning issue, and the last one is the accompanying cleanup and low priority. Based on your comment, this series solves the issue by separating inode object as needed. Since I was worried about the impact of the object composition changes, I tested the series carefully not to cause regressions especially for delicate functions such like disk space reclamation and snapshots. This patch (of 3): If CONFIG_LOCKDEP is enabled, nilfs2 hits lockdep warnings at inode_to_wb() during page/folio operations for btree nodes: WARNING: CPU: 0 PID: 6575 at include/linux/backing-dev.h:269 inode_to_wb include/linux/backing-dev.h:269 [inline] WARNING: CPU: 0 PID: 6575 at include/linux/backing-dev.h:269 folio_account_dirtied mm/page-writeback.c:2460 [inline] WARNING: CPU: 0 PID: 6575 at include/linux/backing-dev.h:269 __folio_mark_dirty+0xa7c/0xe30 mm/page-writeback.c:2509 Modules linked in: ... RIP: 0010:inode_to_wb include/linux/backing-dev.h:269 [inline] RIP: 0010:folio_account_dirtied mm/page-writeback.c:2460 [inline] RIP: 0010:__folio_mark_dirty+0xa7c/0xe30 mm/page-writeback.c:2509 ... Call Trace: __set_page_dirty include/linux/pagemap.h:834 [inline] mark_buffer_dirty+0x4e6/0x650 fs/buffer.c:1145 nilfs_btree_propagate_p fs/nilfs2/btree.c:1889 [inline] nilfs_btree_propagate+0x4ae/0xea0 fs/nilfs2/btree.c:2085 nilfs_bmap_propagate+0x73/0x170 fs/nilfs2/bmap.c:337 nilfs_collect_dat_data+0x45/0xd0 fs/nilfs2/segment.c:625 nilfs_segctor_apply_buffers+0x14a/0x470 fs/nilfs2/segment.c:1009 nilfs_segctor_scan_file+0x47a/0x700 fs/nilfs2/segment.c:1048 nilfs_segctor_collect_blocks fs/nilfs2/segment.c:1224 [inline] nilfs_segctor_collect fs/nilfs2/segment.c:1494 [inline] nilfs_segctor_do_construct+0x14f3/0x6c60 fs/nilfs2/segment.c:2036 nilfs_segctor_construct+0x7a7/0xb30 fs/nilfs2/segment.c:2372 nilfs_segctor_thread_construct fs/nilfs2/segment.c:2480 [inline] nilfs_segctor_thread+0x3c3/0xf90 fs/nilfs2/segment.c:2563 kthread+0x405/0x4f0 kernel/kthread.c:327 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 This is because nilfs2 uses two page caches for each inode and inode->i_mapping never points to one of them, the btree node cache. This causes inode_to_wb(inode) to refer to a different page cache than the caller page/folio operations such like __folio_start_writeback(), __folio_end_writeback(), or __folio_mark_dirty() acquired the lock. This patch resolves the issue by allocating and using an additional inode to hold the page cache of btree nodes. The inode is attached one-to-one to the traditional nilfs2 inode if it requires a block mapping with b-tree. This setup change is in memory only and does not affect the disk format. Link: https://lkml.kernel.org/r/1647867427-30498-1-git-send-email-konishi.ryusuke@gmail.com Link: https://lkml.kernel.org/r/1647867427-30498-2-git-send-email-konishi.ryusuke@gmail.com Link: https://lore.kernel.org/r/YXrYvIo8YRnAOJCj@casper.infradead.org Link: https://lore.kernel.org/r/9a20b33d-b38f-b4a2-4742-c1eb5b8e4d6c@redhat.com Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> Reported-by: syzbot+0d5b462a6f07447991b3@syzkaller.appspotmail.com Reported-by: syzbot+34ef28bb2aeb28724aa0@syzkaller.appspotmail.com Reported-by: Hao Sun <sunhao.th@gmail.com> Reported-by: David Hildenbrand <david@redhat.com> Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> Cc: Matthew Wilcox <willy@infradead.org> 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>
2021-09-26nilfs2: fix memory leak in nilfs_sysfs_delete_snapshot_groupNanyong Sun
[ Upstream commit 17243e1c3072b8417a5ebfc53065d0a87af7ca77 ] kobject_put() should be used to cleanup the memory associated with the kobject instead of kobject_del(). See the section "Kobject removal" of "Documentation/core-api/kobject.rst". Link: https://lkml.kernel.org/r/20210629022556.3985106-7-sunnanyong@huawei.com Link: https://lkml.kernel.org/r/1625651306-10829-7-git-send-email-konishi.ryusuke@gmail.com Signed-off-by: Nanyong Sun <sunnanyong@huawei.com> Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> 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>
2021-09-26nilfs2: fix memory leak in nilfs_sysfs_create_snapshot_groupNanyong Sun
[ Upstream commit b2fe39c248f3fa4bbb2a20759b4fdd83504190f7 ] If kobject_init_and_add returns with error, kobject_put() is needed here to avoid memory leak, because kobject_init_and_add may return error without freeing the memory associated with the kobject it allocated. Link: https://lkml.kernel.org/r/20210629022556.3985106-6-sunnanyong@huawei.com Link: https://lkml.kernel.org/r/1625651306-10829-6-git-send-email-konishi.ryusuke@gmail.com Signed-off-by: Nanyong Sun <sunnanyong@huawei.com> Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> 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>
2021-09-26nilfs2: fix memory leak in nilfs_sysfs_delete_##name##_groupNanyong Sun
[ Upstream commit a3e181259ddd61fd378390977a1e4e2316853afa ] The kobject_put() should be used to cleanup the memory associated with the kobject instead of kobject_del. See the section "Kobject removal" of "Documentation/core-api/kobject.rst". Link: https://lkml.kernel.org/r/20210629022556.3985106-5-sunnanyong@huawei.com Link: https://lkml.kernel.org/r/1625651306-10829-5-git-send-email-konishi.ryusuke@gmail.com Signed-off-by: Nanyong Sun <sunnanyong@huawei.com> Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> 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>
2021-09-26nilfs2: fix memory leak in nilfs_sysfs_create_##name##_groupNanyong Sun
[ Upstream commit 24f8cb1ed057c840728167dab33b32e44147c86f ] If kobject_init_and_add return with error, kobject_put() is needed here to avoid memory leak, because kobject_init_and_add may return error without freeing the memory associated with the kobject it allocated. Link: https://lkml.kernel.org/r/20210629022556.3985106-4-sunnanyong@huawei.com Link: https://lkml.kernel.org/r/1625651306-10829-4-git-send-email-konishi.ryusuke@gmail.com Signed-off-by: Nanyong Sun <sunnanyong@huawei.com> Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> 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>
2021-09-26nilfs2: fix NULL pointer in nilfs_##name##_attr_releaseNanyong Sun
[ Upstream commit dbc6e7d44a514f231a64d9d5676e001b660b6448 ] In nilfs_##name##_attr_release, kobj->parent should not be referenced because it is a NULL pointer. The release() method of kobject is always called in kobject_put(kobj), in the implementation of kobject_put(), the kobj->parent will be assigned as NULL before call the release() method. So just use kobj to get the subgroups, which is more efficient and can fix a NULL pointer reference problem. Link: https://lkml.kernel.org/r/20210629022556.3985106-3-sunnanyong@huawei.com Link: https://lkml.kernel.org/r/1625651306-10829-3-git-send-email-konishi.ryusuke@gmail.com Signed-off-by: Nanyong Sun <sunnanyong@huawei.com> Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> 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>
2021-09-26nilfs2: fix memory leak in nilfs_sysfs_create_device_groupNanyong Sun
[ Upstream commit 5f5dec07aca7067216ed4c1342e464e7307a9197 ] Patch series "nilfs2: fix incorrect usage of kobject". This patchset from Nanyong Sun fixes memory leak issues and a NULL pointer dereference issue caused by incorrect usage of kboject in nilfs2 sysfs implementation. This patch (of 6): Reported by syzkaller: BUG: memory leak unreferenced object 0xffff888100ca8988 (size 8): comm "syz-executor.1", pid 1930, jiffies 4294745569 (age 18.052s) hex dump (first 8 bytes): 6c 6f 6f 70 31 00 ff ff loop1... backtrace: kstrdup+0x36/0x70 mm/util.c:60 kstrdup_const+0x35/0x60 mm/util.c:83 kvasprintf_const+0xf1/0x180 lib/kasprintf.c:48 kobject_set_name_vargs+0x56/0x150 lib/kobject.c:289 kobject_add_varg lib/kobject.c:384 [inline] kobject_init_and_add+0xc9/0x150 lib/kobject.c:473 nilfs_sysfs_create_device_group+0x150/0x7d0 fs/nilfs2/sysfs.c:986 init_nilfs+0xa21/0xea0 fs/nilfs2/the_nilfs.c:637 nilfs_fill_super fs/nilfs2/super.c:1046 [inline] nilfs_mount+0x7b4/0xe80 fs/nilfs2/super.c:1316 legacy_get_tree+0x105/0x210 fs/fs_context.c:592 vfs_get_tree+0x8e/0x2d0 fs/super.c:1498 do_new_mount fs/namespace.c:2905 [inline] path_mount+0xf9b/0x1990 fs/namespace.c:3235 do_mount+0xea/0x100 fs/namespace.c:3248 __do_sys_mount fs/namespace.c:3456 [inline] __se_sys_mount fs/namespace.c:3433 [inline] __x64_sys_mount+0x14b/0x1f0 fs/namespace.c:3433 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0x90 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae If kobject_init_and_add return with error, then the cleanup of kobject is needed because memory may be allocated in kobject_init_and_add without freeing. And the place of cleanup_dev_kobject should use kobject_put to free the memory associated with the kobject. As the section "Kobject removal" of "Documentation/core-api/kobject.rst" says, kobject_del() just makes the kobject "invisible", but it is not cleaned up. And no more cleanup will do after cleanup_dev_kobject, so kobject_put is needed here. Link: https://lkml.kernel.org/r/1625651306-10829-1-git-send-email-konishi.ryusuke@gmail.com Link: https://lkml.kernel.org/r/1625651306-10829-2-git-send-email-konishi.ryusuke@gmail.com Reported-by: Hulk Robot <hulkci@huawei.com> Link: https://lkml.kernel.org/r/20210629022556.3985106-2-sunnanyong@huawei.com Signed-off-by: Nanyong Sun <sunnanyong@huawei.com> Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> 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>
2021-09-26nilfs2: use refcount_dec_and_lock() to fix potential UAFZhen Lei
commit 98e2e409e76ef7781d8511f997359e9c504a95c1 upstream. When the refcount is decreased to 0, the resource reclamation branch is entered. Before CPU0 reaches the race point (1), CPU1 may obtain the spinlock and traverse the rbtree to find 'root', see nilfs_lookup_root(). Although CPU1 will call refcount_inc() to increase the refcount, it is obviously too late. CPU0 will release 'root' directly, CPU1 then accesses 'root' and triggers UAF. Use refcount_dec_and_lock() to ensure that both the operations of decrease refcount to 0 and link deletion are lock protected eliminates this risk. CPU0 CPU1 nilfs_put_root(): <-------- (1) spin_lock(&nilfs->ns_cptree_lock); rb_erase(&root->rb_node, &nilfs->ns_cptree); spin_unlock(&nilfs->ns_cptree_lock); kfree(root); <-------- use-after-free refcount_t: underflow; use-after-free. WARNING: CPU: 2 PID: 9476 at lib/refcount.c:28 \ refcount_warn_saturate+0x1cf/0x210 lib/refcount.c:28 Modules linked in: CPU: 2 PID: 9476 Comm: syz-executor.0 Not tainted 5.10.45-rc1+ #3 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), ... RIP: 0010:refcount_warn_saturate+0x1cf/0x210 lib/refcount.c:28 ... ... Call Trace: __refcount_sub_and_test include/linux/refcount.h:283 [inline] __refcount_dec_and_test include/linux/refcount.h:315 [inline] refcount_dec_and_test include/linux/refcount.h:333 [inline] nilfs_put_root+0xc1/0xd0 fs/nilfs2/the_nilfs.c:795 nilfs_segctor_destroy fs/nilfs2/segment.c:2749 [inline] nilfs_detach_log_writer+0x3fa/0x570 fs/nilfs2/segment.c:2812 nilfs_put_super+0x2f/0xf0 fs/nilfs2/super.c:467 generic_shutdown_super+0xcd/0x1f0 fs/super.c:464 kill_block_super+0x4a/0x90 fs/super.c:1446 deactivate_locked_super+0x6a/0xb0 fs/super.c:335 deactivate_super+0x85/0x90 fs/super.c:366 cleanup_mnt+0x277/0x2e0 fs/namespace.c:1118 __cleanup_mnt+0x15/0x20 fs/namespace.c:1125 task_work_run+0x8e/0x110 kernel/task_work.c:151 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_user_mode_loop kernel/entry/common.c:164 [inline] exit_to_user_mode_prepare+0x13c/0x170 kernel/entry/common.c:191 syscall_exit_to_user_mode+0x16/0x30 kernel/entry/common.c:266 do_syscall_64+0x45/0x80 arch/x86/entry/common.c:56 entry_SYSCALL_64_after_hwframe+0x44/0xa9 There is no reproduction program, and the above is only theoretical analysis. Link: https://lkml.kernel.org/r/1629859428-5906-1-git-send-email-konishi.ryusuke@gmail.com Fixes: ba65ae4729bf ("nilfs2: add checkpoint tree to nilfs object") Link: https://lkml.kernel.org/r/20210723012317.4146-1-thunder.leizhen@huawei.com Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com> Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> 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>
2021-06-30nilfs2: fix memory leak in nilfs_sysfs_delete_device_groupPavel Skripkin
[ Upstream commit 8fd0c1b0647a6bda4067ee0cd61e8395954b6f28 ] My local syzbot instance hit memory leak in nilfs2. The problem was in missing kobject_put() in nilfs_sysfs_delete_device_group(). kobject_del() does not call kobject_cleanup() for passed kobject and it leads to leaking duped kobject name if kobject_put() was not called. Fail log: BUG: memory leak unreferenced object 0xffff8880596171e0 (size 8): comm "syz-executor379", pid 8381, jiffies 4294980258 (age 21.100s) hex dump (first 8 bytes): 6c 6f 6f 70 30 00 00 00 loop0... backtrace: kstrdup+0x36/0x70 mm/util.c:60 kstrdup_const+0x53/0x80 mm/util.c:83 kvasprintf_const+0x108/0x190 lib/kasprintf.c:48 kobject_set_name_vargs+0x56/0x150 lib/kobject.c:289 kobject_add_varg lib/kobject.c:384 [inline] kobject_init_and_add+0xc9/0x160 lib/kobject.c:473 nilfs_sysfs_create_device_group+0x150/0x800 fs/nilfs2/sysfs.c:999 init_nilfs+0xe26/0x12b0 fs/nilfs2/the_nilfs.c:637 Link: https://lkml.kernel.org/r/20210612140559.20022-1-paskripkin@gmail.com Fixes: da7141fb78db ("nilfs2: add /sys/fs/nilfs2/<device> group") Signed-off-by: Pavel Skripkin <paskripkin@gmail.com> Acked-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> Cc: Michael L. Semon <mlsemon35@gmail.com> 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>
2020-06-22nilfs2: fix null pointer dereference at nilfs_segctor_do_construct()Ryusuke Konishi
commit 8301c719a2bd131436438e49130ee381d30933f5 upstream. After commit c3aab9a0bd91 ("mm/filemap.c: don't initiate writeback if mapping has no dirty pages"), the following null pointer dereference has been reported on nilfs2: BUG: kernel NULL pointer dereference, address: 00000000000000a8 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 0 P4D 0 Oops: 0000 [#1] SMP PTI ... RIP: 0010:percpu_counter_add_batch+0xa/0x60 ... Call Trace: __test_set_page_writeback+0x2d3/0x330 nilfs_segctor_do_construct+0x10d3/0x2110 [nilfs2] nilfs_segctor_construct+0x168/0x260 [nilfs2] nilfs_segctor_thread+0x127/0x3b0 [nilfs2] kthread+0xf8/0x130 ... This crash turned out to be caused by set_page_writeback() call for segment summary buffers at nilfs_segctor_prepare_write(). set_page_writeback() can call inc_wb_stat(inode_to_wb(inode), WB_WRITEBACK) where inode_to_wb(inode) is NULL if the inode of underlying block device does not have an associated wb. This fixes the issue by calling inode_attach_wb() in advance to ensure to associate the bdev inode with its wb. Fixes: c3aab9a0bd91 ("mm/filemap.c: don't initiate writeback if mapping has no dirty pages") Reported-by: Walton Hoops <me@waltonhoops.com> Reported-by: Tomas Hlavaty <tom@logand.com> Reported-by: ARAI Shun-ichi <hermes@ceres.dti.ne.jp> Reported-by: Hideki EIRAKU <hdk1983@gmail.com> Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> Cc: <stable@vger.kernel.org> [5.4+] Link: http://lkml.kernel.org/r/20200608.011819.1399059588922299158.konishi.ryusuke@gmail.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-09-04nilfs2: convert to SPDX license tagsRyusuke Konishi
Remove the verbose license text from NILFS2 files and replace them with SPDX tags. This does not change the license of any of the code. Link: http://lkml.kernel.org/r/1535624528-5982-1-git-send-email-konishi.ryusuke@lab.ntt.co.jp Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22fs/nilfs2/file.c: use new return type vm_fault_tSouptick Joarder
Use new return type vm_fault_t for page_mkwrite handler. Link: http://lkml.kernel.org/r/1529555928-2411-1-git-send-email-konishi.ryusuke@lab.ntt.co.jp Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com> Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> Reviewed-by: Matthew Wilcox <mawilcox@microsoft.com> Cc: Matthew Wilcox <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22nilfs2: use 64-bit superblock timstampsArnd Bergmann
The mount time field in the superblock uses a 64-bit timestamp, but calling get_seconds() may truncate the current time to 32 bits. This changes it to ktime_get_real_seconds() to avoid the potential overflow. Link: http://lkml.kernel.org/r/20180620075041.4154396-1-arnd@arndb.de Signed-off-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> Cc: David Howells <dhowells@redhat.com> Cc: Jeff Layton <jlayton@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-05-11do d_instantiate/unlock_new_inode combinations safelyAl Viro
For anything NFS-exported we do _not_ want to unlock new inode before it has grown an alias; original set of fixes got the ordering right, but missed the nasty complication in case of lockdep being enabled - unlock_new_inode() does lockdep_annotate_inode_mutex_key(inode) which can only be done before anyone gets a chance to touch ->i_mutex. Unfortunately, flipping the order and doing unlock_new_inode() before d_instantiate() opens a window when mkdir can race with open-by-fhandle on a guessed fhandle, leading to multiple aliases for a directory inode and all the breakage that follows from that. Correct solution: a new primitive (d_instantiate_new()) combining these two in the right order - lockdep annotate, then d_instantiate(), then the rest of unlock_new_inode(). All combinations of d_instantiate() with unlock_new_inode() should be converted to that. Cc: stable@kernel.org # 2.6.29 and later Tested-by: Mike Marshall <hubcap@omnibond.com> Reviewed-by: Andreas Dilger <adilger@dilger.ca> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-04-11page cache: use xa_lockMatthew Wilcox
Remove the address_space ->tree_lock and use the xa_lock newly added to the radix_tree_root. Rename the address_space ->page_tree to ->i_pages, since we don't really care that it's a tree. [willy@infradead.org: fix nds32, fs/dax.c] Link: http://lkml.kernel.org/r/20180406145415.GB20605@bombadil.infradead.orgLink: http://lkml.kernel.org/r/20180313132639.17387-9-willy@infradead.org Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com> Acked-by: Jeff Layton <jlayton@redhat.com> Cc: Darrick J. Wong <darrick.wong@oracle.com> Cc: Dave Chinner <david@fromorbit.com> Cc: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-06nilfs2: use time64_t internallyArnd Bergmann
The superblock and segment timestamps are used only internally in nilfs2 and can be read out using sysfs. Since we are using the old 'get_seconds()' interface and store the data as timestamps, the behavior differs slightly between 64-bit and 32-bit kernels, the latter will show incorrect timestamps after 2038 in sysfs, and presumably fail completely in 2106 as comparisons go wrong. This changes nilfs2 to use time64_t with ktime_get_real_seconds() to handle timestamps, making the behavior consistent and correct on both 32-bit and 64-bit machines. The on-disk format already uses 64-bit timestamps, so nothing changes there. Link: http://lkml.kernel.org/r/20180122211050.1286441-1-arnd@arndb.de Signed-off-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> Cc: Jens Axboe <axboe@kernel.dk> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jan Kara <jack@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-27Rename superblock flags (MS_xyz -> SB_xyz)Linus Torvalds
This is a pure automated search-and-replace of the internal kernel superblock flags. The s_flags are now called SB_*, with the names and the values for the moment mirroring the MS_* flags that they're equivalent to. Note how the MS_xyz flags are the ones passed to the mount system call, while the SB_xyz flags are what we then use in sb->s_flags. The script to do this was: # places to look in; re security/*: it generally should *not* be # touched (that stuff parses mount(2) arguments directly), but # there are two places where we really deal with superblock flags. FILES="drivers/mtd drivers/staging/lustre fs ipc mm \ include/linux/fs.h include/uapi/linux/bfs_fs.h \ security/apparmor/apparmorfs.c security/apparmor/include/lib.h" # the list of MS_... constants SYMS="RDONLY NOSUID NODEV NOEXEC SYNCHRONOUS REMOUNT MANDLOCK \ DIRSYNC NOATIME NODIRATIME BIND MOVE REC VERBOSE SILENT \ POSIXACL UNBINDABLE PRIVATE SLAVE SHARED RELATIME KERNMOUNT \ I_VERSION STRICTATIME LAZYTIME SUBMOUNT NOREMOTELOCK NOSEC BORN \ ACTIVE NOUSER" SED_PROG= for i in $SYMS; do SED_PROG="$SED_PROG -e s/MS_$i/SB_$i/g"; done # we want files that contain at least one of MS_..., # with fs/namespace.c and fs/pnode.c excluded. L=$(for i in $SYMS; do git grep -w -l MS_$i $FILES; done| sort|uniq|grep -v '^fs/namespace.c'|grep -v '^fs/pnode.c') for f in $L; do sed -i $f $SED_PROG; done Requested-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-17nilfs2: remove inode->i_version initializationJeff Layton
It's never used in nilfs2. Link: http://lkml.kernel.org/r/1510064486-1728-2-git-send-email-konishi.ryusuke@lab.ntt.co.jp Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-17nilfs2: use octal for unreadable permission macroRyusuke Konishi
Replace S_IRWXUGO with 0777 because symbolic permissions are considered harmful: https://lwn.net/Articles/696229/ Link: http://lkml.kernel.org/r/1509367935-3086-5-git-send-email-konishi.ryusuke@lab.ntt.co.jp Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>