aboutsummaryrefslogtreecommitdiffstats
path: root/security/selinux
AgeCommit message (Collapse)Author
2024-03-15lsm: make security_socket_getpeersec_stream() sockptr_t safePaul Moore
[ Upstream commit b10b9c342f7571f287fd422be5d5c0beb26ba974 ] Commit 4ff09db1b79b ("bpf: net: Change sk_getsockopt() to take the sockptr_t argument") made it possible to call sk_getsockopt() with both user and kernel address space buffers through the use of the sockptr_t type. Unfortunately at the time of conversion the security_socket_getpeersec_stream() LSM hook was written to only accept userspace buffers, and in a desire to avoid having to change the LSM hook the commit author simply passed the sockptr_t's userspace buffer pointer. Since the only sk_getsockopt() callers at the time of conversion which used kernel sockptr_t buffers did not allow SO_PEERSEC, and hence the security_socket_getpeersec_stream() hook, this was acceptable but also very fragile as future changes presented the possibility of silently passing kernel space pointers to the LSM hook. There are several ways to protect against this, including careful code review of future commits, but since relying on code review to catch bugs is a recipe for disaster and the upstream eBPF maintainer is "strongly against defensive programming", this patch updates the LSM hook, and all of the implementations to support sockptr_t and safely handle both user and kernel space buffers. Acked-by: Casey Schaufler <casey@schaufler-ca.com> Acked-by: John Johansen <john.johansen@canonical.com> Signed-off-by: Paul Moore <paul@paul-moore.com> Stable-dep-of: 5a287d3d2b9d ("lsm: fix default return value of the socket_getpeersec_*() hooks") Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-02-23lsm: new security_file_ioctl_compat() hookAlfred Piccioni
commit f1bb47a31dff6d4b34fb14e99850860ee74bb003 upstream. Some ioctl commands do not require ioctl permission, but are routed to other permissions such as FILE_GETATTR or FILE_SETATTR. This routing is done by comparing the ioctl cmd to a set of 64-bit flags (FS_IOC_*). However, if a 32-bit process is running on a 64-bit kernel, it emits 32-bit flags (FS_IOC32_*) for certain ioctl operations. These flags are being checked erroneously, which leads to these ioctl operations being routed to the ioctl permission, rather than the correct file permissions. This was also noted in a RED-PEN finding from a while back - "/* RED-PEN how should LSM module know it's handling 32bit? */". This patch introduces a new hook, security_file_ioctl_compat(), that is called from the compat ioctl syscall. All current LSMs have been changed to support this hook. Reviewing the three places where we are currently using security_file_ioctl(), it appears that only SELinux needs a dedicated compat change; TOMOYO and SMACK appear to be functional without any change. Cc: stable@vger.kernel.org Fixes: 0b24dcb7f2f7 ("Revert "selinux: simplify ioctl checking"") Signed-off-by: Alfred Piccioni <alpic@google.com> Reviewed-by: Stephen Smalley <stephen.smalley.work@gmail.com> [PM: subject tweak, line length fixes, and alignment corrections] Signed-off-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-25selinux: Fix error priority for bind with AF_UNSPEC on PF_INET6 socketMickaël Salaün
[ Upstream commit bbf5a1d0e5d0fb3bdf90205aa872636122692a50 ] The IPv6 network stack first checks the sockaddr length (-EINVAL error) before checking the family (-EAFNOSUPPORT error). This was discovered thanks to commit a549d055a22e ("selftests/landlock: Add network tests"). Cc: Eric Paris <eparis@parisplace.org> Cc: Konstantin Meskhidze <konstantin.meskhidze@huawei.com> Cc: Paul Moore <paul@paul-moore.com> Cc: Stephen Smalley <stephen.smalley.work@gmail.com> Reported-by: Muhammad Usama Anjum <usama.anjum@collabora.com> Closes: https://lore.kernel.org/r/0584f91c-537c-4188-9e4f-04f192565667@collabora.com Fixes: 0f8db8cc73df ("selinux: add AF_UNSPEC and INADDR_ANY checks to selinux_socket_bind()") Signed-off-by: Mickaël Salaün <mic@digikod.net> Tested-by: Muhammad Usama Anjum <usama.anjum@collabora.com> Signed-off-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-08-30selinux: set next pointer before attaching to listChristian Göttsche
commit 70d91dc9b2ac91327d0eefd86163abc3548effa6 upstream. Set the next pointer in filename_trans_read_helper() before attaching the new node under construction to the list, otherwise garbage would be dereferenced on subsequent failure during cleanup in the out goto label. Cc: <stable@vger.kernel.org> Fixes: 430059024389 ("selinux: implement new format of filename transitions") Signed-off-by: Christian Göttsche <cgzones@googlemail.com> Signed-off-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-06-09selinux: don't use make's grouped targets feature yetPaul Moore
commit 42c4e97e06a839b07d834f640a10911ad84ec8b3 upstream. The Linux Kernel currently only requires make v3.82 while the grouped target functionality requires make v4.3. Removed the grouped target introduced in 4ce1f694eb5d ("selinux: ensure av_permissions.h is built when needed") as well as the multiple header file targets in the make rule. This effectively reverts the problem commit. We will revisit this change when make >= 4.3 is required by the rest of the kernel. Cc: stable@vger.kernel.org Fixes: 4ce1f694eb5d ("selinux: ensure av_permissions.h is built when needed") Reported-by: Erwan Velu <e.velu@criteo.com> Reported-by: Luiz Capitulino <luizcap@amazon.com> Tested-by: Luiz Capitulino <luizcap@amazon.com> Signed-off-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-05-17selinux: ensure av_permissions.h is built when neededPaul Moore
[ Upstream commit 4ce1f694eb5d8ca607fed8542d32a33b4f1217a5 ] The Makefile rule responsible for building flask.h and av_permissions.h only lists flask.h as a target which means that av_permissions.h is only generated when flask.h needs to be generated. This patch fixes this by adding av_permissions.h as a target to the rule. Fixes: 8753f6bec352 ("selinux: generate flask headers during kernel build") Signed-off-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-05-17selinux: fix Makefile dependencies of flask.hOndrej Mosnacek
[ Upstream commit bcab1adeaad4b39a1e04cb98979a367d08253f03 ] Make the flask.h target depend on the genheaders binary instead of classmap.h to ensure that it is rebuilt if any of the dependencies of genheaders are changed. Notably this fixes flask.h not being rebuilt when initial_sid_to_string.h is modified. Fixes: 8753f6bec352 ("selinux: generate flask headers during kernel build") Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com> Acked-by: Stephen Smalley <stephen.smalley.work@gmail.com> Signed-off-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-10-30selinux: enable use of both GFP_KERNEL and GFP_ATOMIC in convert_context()GONG, Ruiqi
commit abe3c631447dcd1ba7af972fe6f054bee6f136fa upstream. The following warning was triggered on a hardware environment: SELinux: Converting 162 SID table entries... BUG: sleeping function called from invalid context at __might_sleep+0x60/0x74 0x0 in_atomic(): 1, irqs_disabled(): 128, non_block: 0, pid: 5943, name: tar CPU: 7 PID: 5943 Comm: tar Tainted: P O 5.10.0 #1 Call trace: dump_backtrace+0x0/0x1c8 show_stack+0x18/0x28 dump_stack+0xe8/0x15c ___might_sleep+0x168/0x17c __might_sleep+0x60/0x74 __kmalloc_track_caller+0xa0/0x7dc kstrdup+0x54/0xac convert_context+0x48/0x2e4 sidtab_context_to_sid+0x1c4/0x36c security_context_to_sid_core+0x168/0x238 security_context_to_sid_default+0x14/0x24 inode_doinit_use_xattr+0x164/0x1e4 inode_doinit_with_dentry+0x1c0/0x488 selinux_d_instantiate+0x20/0x34 security_d_instantiate+0x70/0xbc d_splice_alias+0x4c/0x3c0 ext4_lookup+0x1d8/0x200 [ext4] __lookup_slow+0x12c/0x1e4 walk_component+0x100/0x200 path_lookupat+0x88/0x118 filename_lookup+0x98/0x130 user_path_at_empty+0x48/0x60 vfs_statx+0x84/0x140 vfs_fstatat+0x20/0x30 __se_sys_newfstatat+0x30/0x74 __arm64_sys_newfstatat+0x1c/0x2c el0_svc_common.constprop.0+0x100/0x184 do_el0_svc+0x1c/0x2c el0_svc+0x20/0x34 el0_sync_handler+0x80/0x17c el0_sync+0x13c/0x140 SELinux: Context system_u:object_r:pssp_rsyslog_log_t:s0:c0 is not valid (left unmapped). It was found that within a critical section of spin_lock_irqsave in sidtab_context_to_sid(), convert_context() (hooked by sidtab_convert_params.func) might cause the process to sleep via allocating memory with GFP_KERNEL, which is problematic. As Ondrej pointed out [1], convert_context()/sidtab_convert_params.func has another caller sidtab_convert_tree(), which is okay with GFP_KERNEL. Therefore, fix this problem by adding a gfp_t argument for convert_context()/sidtab_convert_params.func and pass GFP_KERNEL/_ATOMIC properly in individual callers. Cc: stable@vger.kernel.org Link: https://lore.kernel.org/all/20221018120111.1474581-1-gongruiqi1@huawei.com/ [1] Reported-by: Tan Ninghao <tanninghao1@huawei.com> Fixes: ee1a84fdfeed ("selinux: overhaul sidtab to fix bug and improve performance") Signed-off-by: GONG, Ruiqi <gongruiqi1@huawei.com> Reviewed-by: Ondrej Mosnacek <omosnace@redhat.com> [PM: wrap long BUG() output lines, tweak subject line] Signed-off-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-08-21selinux: Add boundary check in put_entry()Xiu Jianfeng
[ Upstream commit 15ec76fb29be31df2bccb30fc09875274cba2776 ] Just like next_entry(), boundary check is necessary to prevent memory out-of-bound access. Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com> Signed-off-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-06-09lsm,selinux: pass flowi_common instead of flowi to the LSM hooksPaul Moore
[ Upstream commit 3df98d79215ace13d1e91ddfc5a67a0f5acbd83f ] As pointed out by Herbert in a recent related patch, the LSM hooks do not have the necessary address family information to use the flowi struct safely. As none of the LSMs currently use any of the protocol specific flowi information, replace the flowi pointers with pointers to the address family independent flowi_common struct. Reported-by: Herbert Xu <herbert@gondor.apana.org.au> Acked-by: James Morris <jamorris@linux.microsoft.com> Signed-off-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-05-25include/uapi/linux/xfrm.h: Fix XFRM_MSG_MAPPING ABI breakageEugene Syromiatnikov
commit 844f7eaaed9267ae17d33778efe65548cc940205 upstream. Commit 2d151d39073a ("xfrm: Add possibility to set the default to block if we have no policy") broke ABI by changing the value of the XFRM_MSG_MAPPING enum item, thus also evading the build-time check in security/selinux/nlmsgtab.c:selinux_nlmsg_lookup for presence of proper security permission checks in nlmsg_xfrm_perms. Fix it by placing XFRM_MSG_SETDEFAULT/XFRM_MSG_GETDEFAULT to the end of the enum, right before __XFRM_MSG_MAX, and updating the nlmsg_xfrm_perms accordingly. Fixes: 2d151d39073a ("xfrm: Add possibility to set the default to block if we have no policy") References: https://lore.kernel.org/netdev/20210901151402.GA2557@altlinux.org/ Signed-off-by: Eugene Syromiatnikov <esyr@redhat.com> Acked-by: Antony Antony <antony.antony@secunet.com> Acked-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-05-25selinux: fix bad cleanup on error in hashtab_duplicate()Ondrej Mosnacek
commit 6254bd3db316c9ccb3b05caa8b438be63245466f upstream. The code attempts to free the 'new' pointer using kmem_cache_free(), which is wrong because this function isn't responsible of freeing it. Instead, the function should free new->htable and clear the contents of *new (to prevent double-free). Cc: stable@vger.kernel.org Fixes: c7c556f1e81b ("selinux: refactor changing booleans") Reported-by: Wander Lairson Costa <wander@redhat.com> Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-08selinux: allow FIOCLEX and FIONCLEX with policy capabilityRichard Haines
[ Upstream commit 65881e1db4e948614d9eb195b8e1197339822949 ] These ioctls are equivalent to fcntl(fd, F_SETFD, flags), which SELinux always allows too. Furthermore, a failed FIOCLEX could result in a file descriptor being leaked to a process that should not have access to it. As this patch removes access controls, a policy capability needs to be enabled in policy to always allow these ioctls. Based-on-patch-by: Demi Marie Obenour <demiobenour@gmail.com> Signed-off-by: Richard Haines <richard_c_haines@btinternet.com> [PM: subject line tweak] Signed-off-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-04-08selinux: use correct type for context lengthChristian Göttsche
[ Upstream commit b97df7c098c531010e445da88d02b7bf7bf59ef6 ] security_sid_to_context() expects a pointer to an u32 as the address where to store the length of the computed context. Reported by sparse: security/selinux/xfrm.c:359:39: warning: incorrect type in arg 4 (different signedness) security/selinux/xfrm.c:359:39: expected unsigned int [usertype] *scontext_len security/selinux/xfrm.c:359:39: got int * Signed-off-by: Christian Göttsche <cgzones@googlemail.com> [PM: wrapped commit description] Signed-off-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-04-08LSM: general protection fault in legacy_parse_paramCasey Schaufler
[ Upstream commit ecff30575b5ad0eda149aadad247b7f75411fd47 ] The usual LSM hook "bail on fail" scheme doesn't work for cases where a security module may return an error code indicating that it does not recognize an input. In this particular case Smack sees a mount option that it recognizes, and returns 0. A call to a BPF hook follows, which returns -ENOPARAM, which confuses the caller because Smack has processed its data. The SELinux hook incorrectly returns 1 on success. There was a time when this was correct, however the current expectation is that it return 0 on success. This is repaired. Reported-by: syzbot+d1e3b1d92d25abf97943@syzkaller.appspotmail.com Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> Acked-by: James Morris <jamorris@linux.microsoft.com> Signed-off-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-04-08selinux: check return value of sel_make_avc_filesChristian Göttsche
[ Upstream commit bcb62828e3e8c813b6613db6eb7fd9657db248fc ] sel_make_avc_files() might fail and return a negative errno value on memory allocation failures. Re-add the check of the return value, dropped in 66f8e2f03c02 ("selinux: sidtab reverse lookup hash table"). Reported by clang-analyzer: security/selinux/selinuxfs.c:2129:2: warning: Value stored to 'ret' is never read [deadcode.DeadStores] ret = sel_make_avc_files(dentry); ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~ Fixes: 66f8e2f03c02 ("selinux: sidtab reverse lookup hash table") Signed-off-by: Christian Göttsche <cgzones@googlemail.com> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> [PM: description line wrapping, added proper commit ref] Signed-off-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-02-08selinux: fix double free of cond_list on error pathsVratislav Bendel
commit 186edf7e368c40d06cf727a1ad14698ea67b74ad upstream. On error path from cond_read_list() and duplicate_policydb_cond_list() the cond_list_destroy() gets called a second time in caller functions, resulting in NULL pointer deref. Fix this by resetting the cond_list_len to 0 in cond_list_destroy(), making subsequent calls a noop. Also consistently reset the cond_list pointer to NULL after freeing. Cc: stable@vger.kernel.org Signed-off-by: Vratislav Bendel <vbendel@redhat.com> [PM: fix line lengths in the description] Signed-off-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-01-27selinux: fix potential memleak in selinux_add_opt()Bernard Zhao
[ Upstream commit 2e08df3c7c4e4e74e3dd5104c100f0bf6288aaa8 ] This patch try to fix potential memleak in error branch. Fixes: ba6418623385 ("selinux: new helper - selinux_add_opt()") Signed-off-by: Bernard Zhao <bernard@vivo.com> [PM: tweak the subject line, add Fixes tag] Signed-off-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-01-05selinux: initialize proto variable in selinux_ip_postroute_compat()Tom Rix
commit 732bc2ff080c447f8524f40c970c481f5da6eed3 upstream. Clang static analysis reports this warning hooks.c:5765:6: warning: 4th function call argument is an uninitialized value if (selinux_xfrm_postroute_last(sksec->sid, skb, &ad, proto)) ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ selinux_parse_skb() can return ok without setting proto. The later call to selinux_xfrm_postroute_last() does an early check of proto and can return ok if the garbage proto value matches. So initialize proto. Cc: stable@vger.kernel.org Fixes: eef9b41622f2 ("selinux: cleanup selinux_xfrm_sock_rcv_skb() and selinux_xfrm_postroute_last()") Signed-off-by: Tom Rix <trix@redhat.com> [PM: typo/spelling and checkpatch.pl description fixes] Signed-off-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-11-26selinux: fix NULL-pointer dereference when hashtab allocation failsOndrej Mosnacek
commit dc27f3c5d10c58069672215787a96b4fae01818b upstream. When the hash table slot array allocation fails in hashtab_init(), h->size is left initialized with a non-zero value, but the h->htable pointer is NULL. This may then cause a NULL pointer dereference, since the policydb code relies on the assumption that even after a failed hashtab_init(), hashtab_map() and hashtab_destroy() can be safely called on it. Yet, these detect an empty hashtab only by looking at the size. Fix this by making sure that hashtab_init() always leaves behind a valid empty hashtab when the allocation fails. Cc: stable@vger.kernel.org Fixes: 03414a49ad5f ("selinux: do not allocate hashtabs dynamically") Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-11-18selinux: fix race condition when computing ocontext SIDsOndrej Mosnacek
commit cbfcd13be5cb2a07868afe67520ed181956579a7 upstream. Current code contains a lot of racy patterns when converting an ocontext's context structure to an SID. This is being done in a "lazy" fashion, such that the SID is looked up in the SID table only when it's first needed and then cached in the "sid" field of the ocontext structure. However, this is done without any locking or memory barriers and is thus unsafe. Between commits 24ed7fdae669 ("selinux: use separate table for initial SID lookup") and 66f8e2f03c02 ("selinux: sidtab reverse lookup hash table"), this race condition lead to an actual observable bug, because a pointer to the shared sid field was passed directly to sidtab_context_to_sid(), which was using this location to also store an intermediate value, which could have been read by other threads and interpreted as an SID. In practice this caused e.g. new mounts to get a wrong (seemingly random) filesystem context, leading to strange denials. This bug has been spotted in the wild at least twice, see [1] and [2]. Fix the race condition by making all the racy functions use a common helper that ensures the ocontext::sid accesses are made safely using the appropriate SMP constructs. Note that security_netif_sid() was populating the sid field of both contexts stored in the ocontext, but only the first one was actually used. The SELinux wiki's documentation on the "netifcon" policy statement [3] suggests that using only the first context is intentional. I kept only the handling of the first context here, as there is really no point in doing the SID lookup for the unused one. I wasn't able to reproduce the bug mentioned above on any kernel that includes commit 66f8e2f03c02, even though it has been reported that the issue occurs with that commit, too, just less frequently. Thus, I wasn't able to verify that this patch fixes the issue, but it makes sense to avoid the race condition regardless. [1] https://github.com/containers/container-selinux/issues/89 [2] https://lists.fedoraproject.org/archives/list/selinux@lists.fedoraproject.org/thread/6DMTAMHIOAOEMUAVTULJD45JZU7IBAFM/ [3] https://selinuxproject.org/page/NetworkStatements#netifcon Cc: stable@vger.kernel.org Cc: Xinjie Zheng <xinjie@google.com> Reported-by: Sujithra Periasamy <sujithra@google.com> Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-11-18binder: use cred instead of task for selinux checksTodd Kjos
commit 52f88693378a58094c538662ba652aff0253c4fe upstream. Since binder was integrated with selinux, it has passed 'struct task_struct' associated with the binder_proc to represent the source and target of transactions. The conversion of task to SID was then done in the hook implementations. It turns out that there are race conditions which can result in an incorrect security context being used. Fix by using the 'struct cred' saved during binder_open and pass it to the selinux subsystem. Cc: stable@vger.kernel.org # 5.14 (need backport for earlier stables) Fixes: 79af73079d75 ("Add security hooks to binder and implement the hooks for SELinux.") Suggested-by: Jann Horn <jannh@google.com> Signed-off-by: Todd Kjos <tkjos@google.com> Acked-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-08-12selinux: correct the return value when loads initial sidsXiu Jianfeng
commit 4c156084daa8ee70978e4b150b5eb5fc7b1f15be upstream. It should not return 0 when SID 0 is assigned to isids. This patch fixes it. Cc: stable@vger.kernel.org Fixes: e3e0b582c321a ("selinux: remove unused initial SIDs and improve handling") Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com> [PM: remove changelog from description] Signed-off-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-07-19selinux: use __GFP_NOWARN with GFP_NOWAIT in the AVCMinchan Kim
[ Upstream commit 648f2c6100cfa18e7dfe43bc0b9c3b73560d623c ] In the field, we have seen lots of allocation failure from the call path below. 06-03 13:29:12.999 1010315 31557 31557 W Binder : 31542_2: page allocation failure: order:0, mode:0x800(GFP_NOWAIT), nodemask=(null),cpuset=background,mems_allowed=0 ... ... 06-03 13:29:12.999 1010315 31557 31557 W Call trace: 06-03 13:29:12.999 1010315 31557 31557 W : dump_backtrace.cfi_jt+0x0/0x8 06-03 13:29:12.999 1010315 31557 31557 W : dump_stack+0xc8/0x14c 06-03 13:29:12.999 1010315 31557 31557 W : warn_alloc+0x158/0x1c8 06-03 13:29:12.999 1010315 31557 31557 W : __alloc_pages_slowpath+0x9d8/0xb80 06-03 13:29:12.999 1010315 31557 31557 W : __alloc_pages_nodemask+0x1c4/0x430 06-03 13:29:12.999 1010315 31557 31557 W : allocate_slab+0xb4/0x390 06-03 13:29:12.999 1010315 31557 31557 W : ___slab_alloc+0x12c/0x3a4 06-03 13:29:12.999 1010315 31557 31557 W : kmem_cache_alloc+0x358/0x5e4 06-03 13:29:12.999 1010315 31557 31557 W : avc_alloc_node+0x30/0x184 06-03 13:29:12.999 1010315 31557 31557 W : avc_update_node+0x54/0x4f0 06-03 13:29:12.999 1010315 31557 31557 W : avc_has_extended_perms+0x1a4/0x460 06-03 13:29:12.999 1010315 31557 31557 W : selinux_file_ioctl+0x320/0x3d0 06-03 13:29:12.999 1010315 31557 31557 W : __arm64_sys_ioctl+0xec/0x1fc 06-03 13:29:12.999 1010315 31557 31557 W : el0_svc_common+0xc0/0x24c 06-03 13:29:12.999 1010315 31557 31557 W : el0_svc+0x28/0x88 06-03 13:29:12.999 1010315 31557 31557 W : el0_sync_handler+0x8c/0xf0 06-03 13:29:12.999 1010315 31557 31557 W : el0_sync+0x1a4/0x1c0 .. .. 06-03 13:29:12.999 1010315 31557 31557 W SLUB : Unable to allocate memory on node -1, gfp=0x900(GFP_NOWAIT|__GFP_ZERO) 06-03 13:29:12.999 1010315 31557 31557 W cache : avc_node, object size: 72, buffer size: 80, default order: 0, min order: 0 06-03 13:29:12.999 1010315 31557 31557 W node 0 : slabs: 57, objs: 2907, free: 0 06-03 13:29:12.999 1010161 10686 10686 W SLUB : Unable to allocate memory on node -1, gfp=0x900(GFP_NOWAIT|__GFP_ZERO) 06-03 13:29:12.999 1010161 10686 10686 W cache : avc_node, object size: 72, buffer size: 80, default order: 0, min order: 0 06-03 13:29:12.999 1010161 10686 10686 W node 0 : slabs: 57, objs: 2907, free: 0 06-03 13:29:12.999 1010161 10686 10686 W SLUB : Unable to allocate memory on node -1, gfp=0x900(GFP_NOWAIT|__GFP_ZERO) 06-03 13:29:12.999 1010161 10686 10686 W cache : avc_node, object size: 72, buffer size: 80, default order: 0, min order: 0 06-03 13:29:12.999 1010161 10686 10686 W node 0 : slabs: 57, objs: 2907, free: 0 06-03 13:29:12.999 1010161 10686 10686 W SLUB : Unable to allocate memory on node -1, gfp=0x900(GFP_NOWAIT|__GFP_ZERO) 06-03 13:29:12.999 1010161 10686 10686 W cache : avc_node, object size: 72, buffer size: 80, default order: 0, min order: 0 06-03 13:29:12.999 1010161 10686 10686 W node 0 : slabs: 57, objs: 2907, free: 0 06-03 13:29:13.000 1010161 10686 10686 W SLUB : Unable to allocate memory on node -1, gfp=0x900(GFP_NOWAIT|__GFP_ZERO) 06-03 13:29:13.000 1010161 10686 10686 W cache : avc_node, object size: 72, buffer size: 80, default order: 0, min order: 0 06-03 13:29:13.000 1010161 10686 10686 W node 0 : slabs: 57, objs: 2907, free: 0 06-03 13:29:13.000 1010161 10686 10686 W SLUB : Unable to allocate memory on node -1, gfp=0x900(GFP_NOWAIT|__GFP_ZERO) 06-03 13:29:13.000 1010161 10686 10686 W cache : avc_node, object size: 72, buffer size: 80, default order: 0, min order: 0 06-03 13:29:13.000 1010161 10686 10686 W node 0 : slabs: 57, objs: 2907, free: 0 06-03 13:29:13.000 1010161 10686 10686 W SLUB : Unable to allocate memory on node -1, gfp=0x900(GFP_NOWAIT|__GFP_ZERO) 06-03 13:29:13.000 1010161 10686 10686 W cache : avc_node, object size: 72, buffer size: 80, default order: 0, min order: 0 06-03 13:29:13.000 1010161 10686 10686 W node 0 : slabs: 57, objs: 2907, free: 0 06-03 13:29:13.000 10230 30892 30892 W SLUB : Unable to allocate memory on node -1, gfp=0x900(GFP_NOWAIT|__GFP_ZERO) 06-03 13:29:13.000 10230 30892 30892 W cache : avc_node, object size: 72, buffer size: 80, default order: 0, min order: 0 06-03 13:29:13.000 10230 30892 30892 W node 0 : slabs: 57, objs: 2907, free: 0 06-03 13:29:13.000 10230 30892 30892 W SLUB : Unable to allocate memory on node -1, gfp=0x900(GFP_NOWAIT|__GFP_ZERO) 06-03 13:29:13.000 10230 30892 30892 W cache : avc_node, object size: 72, buffer size: 80, default order: 0, min order: 0 Based on [1], selinux is tolerate for failure of memory allocation. Then, use __GFP_NOWARN together. [1] 476accbe2f6e ("selinux: use GFP_NOWAIT in the AVC kmem_caches") Signed-off-by: Minchan Kim <minchan@kernel.org> [PM: subj fix, line wraps, normalized commit refs] Signed-off-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-05-14selinux: add proper NULL termination to the secclass_map permissionsPaul Moore
commit e4c82eafb609c2badc56f4e11bc50fcf44b8e9eb upstream. This patch adds the missing NULL termination to the "bpf" and "perf_event" object class permission lists. This missing NULL termination should really only affect the tools under scripts/selinux, with the most important being genheaders.c, although in practice this has not been an issue on any of my dev/test systems. If the problem were to manifest itself it would likely result in bogus permissions added to the end of the object class; thankfully with no access control checks using these bogus permissions and no policies defining these permissions the impact would likely be limited to some noise about undefined permissions during policy load. Cc: stable@vger.kernel.org Fixes: ec27c3568a34 ("selinux: bpf: Add selinux check for eBPF syscall operations") Fixes: da97e18458fb ("perf_event: Add support for LSM and SELinux checks") Signed-off-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-14selinux: fix race between old and new sidtabOndrej Mosnacek
commit 9ad6e9cb39c66366bf7b9aece114aca277981a1f upstream. Since commit 1b8b31a2e612 ("selinux: convert policy read-write lock to RCU"), there is a small window during policy load where the new policy pointer has already been installed, but some threads may still be holding the old policy pointer in their read-side RCU critical sections. This means that there may be conflicting attempts to add a new SID entry to both tables via sidtab_context_to_sid(). See also (and the rest of the thread): https://lore.kernel.org/selinux/CAFqZXNvfux46_f8gnvVvRYMKoes24nwm2n3sPbMjrB8vKTW00g@mail.gmail.com/ Fix this by installing the new policy pointer under the old sidtab's spinlock along with marking the old sidtab as "frozen". Then, if an attempt to add new entry to a "frozen" sidtab is detected, make sidtab_context_to_sid() return -ESTALE to indicate that a new policy has been installed and that the caller will have to abort the policy transaction and try again after re-taking the policy pointer (which is guaranteed to be a newer policy). This requires adding a retry-on-ESTALE logic to all callers of sidtab_context_to_sid(), but fortunately these are easy to determine and aren't that many. This seems to be the simplest solution for this problem, even if it looks somewhat ugly. Note that other places in the kernel (e.g. do_mknodat() in fs/namei.c) use similar stale-retry patterns, so I think it's reasonable. Cc: stable@vger.kernel.org Fixes: 1b8b31a2e612 ("selinux: convert policy read-write lock to RCU") Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-14selinux: fix cond_list corruption when changing booleansOndrej Mosnacek
commit d8f5f0ea5b86300390b026b6c6e7836b7150814a upstream. Currently, duplicate_policydb_cond_list() first copies the whole conditional avtab and then tries to link to the correct entries in cond_dup_av_list() using avtab_search(). However, since the conditional avtab may contain multiple entries with the same key, this approach often fails to find the right entry, potentially leading to wrong rules being activated/deactivated when booleans are changed. To fix this, instead start with an empty conditional avtab and add the individual entries one-by-one while building the new av_lists. This approach leads to the correct result, since each entry is present in the av_lists exactly once. The issue can be reproduced with Fedora policy as follows: # sesearch -s ftpd_t -t public_content_rw_t -c dir -p create -A allow ftpd_t non_security_file_type:dir { add_name create getattr ioctl link lock open read remove_name rename reparent rmdir search setattr unlink watch watch_reads write }; [ ftpd_full_access ]:True allow ftpd_t public_content_rw_t:dir { add_name create link remove_name rename reparent rmdir setattr unlink watch watch_reads write }; [ ftpd_anon_write ]:True # setsebool ftpd_anon_write=off ftpd_connect_all_unreserved=off ftpd_connect_db=off ftpd_full_access=off On fixed kernels, the sesearch output is the same after the setsebool command: # sesearch -s ftpd_t -t public_content_rw_t -c dir -p create -A allow ftpd_t non_security_file_type:dir { add_name create getattr ioctl link lock open read remove_name rename reparent rmdir search setattr unlink watch watch_reads write }; [ ftpd_full_access ]:True allow ftpd_t public_content_rw_t:dir { add_name create link remove_name rename reparent rmdir setattr unlink watch watch_reads write }; [ ftpd_anon_write ]:True While on the broken kernels, it will be different: # sesearch -s ftpd_t -t public_content_rw_t -c dir -p create -A allow ftpd_t non_security_file_type:dir { add_name create getattr ioctl link lock open read remove_name rename reparent rmdir search setattr unlink watch watch_reads write }; [ ftpd_full_access ]:True allow ftpd_t non_security_file_type:dir { add_name create getattr ioctl link lock open read remove_name rename reparent rmdir search setattr unlink watch watch_reads write }; [ ftpd_full_access ]:True allow ftpd_t non_security_file_type:dir { add_name create getattr ioctl link lock open read remove_name rename reparent rmdir search setattr unlink watch watch_reads write }; [ ftpd_full_access ]:True While there, also simplify the computation of nslots. This changes the nslots values for nrules 2 or 3 to just two slots instead of 4, which makes the sequence more consistent. Cc: stable@vger.kernel.org Fixes: c7c556f1e81b ("selinux: refactor changing booleans") Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-14selinux: make nslot handling in avtab more robustOndrej Mosnacek
commit 442dc00f82a9727dc0c48c44f792c168f593c6df upstream. 1. Make sure all fileds are initialized in avtab_init(). 2. Slightly refactor avtab_alloc() to use the above fact. 3. Use h->nslot == 0 as a sentinel in the access functions to prevent dereferencing h->htable when it's not allocated. Cc: stable@vger.kernel.org Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-30selinux: fix variable scope issue in live sidtab conversionOndrej Mosnacek
commit 6406887a12ee5dcdaffff1a8508d91113d545559 upstream. Commit 02a52c5c8c3b ("selinux: move policy commit after updating selinuxfs") moved the selinux_policy_commit() call out of security_load_policy() into sel_write_load(), which caused a subtle yet rather serious bug. The problem is that security_load_policy() passes a reference to the convert_params local variable to sidtab_convert(), which stores it in the sidtab, where it may be accessed until the policy is swapped over and RCU synchronized. Before 02a52c5c8c3b, selinux_policy_commit() was called directly from security_load_policy(), so the convert_params pointer remained valid all the way until the old sidtab was destroyed, but now that's no longer the case and calls to sidtab_context_to_sid() on the old sidtab after security_load_policy() returns may cause invalid memory accesses. This can be easily triggered using the stress test from commit ee1a84fdfeed ("selinux: overhaul sidtab to fix bug and improve performance"): ``` function rand_cat() { echo $(( $RANDOM % 1024 )) } function do_work() { while true; do echo -n "system_u:system_r:kernel_t:s0:c$(rand_cat),c$(rand_cat)" \ >/sys/fs/selinux/context 2>/dev/null || true done } do_work >/dev/null & do_work >/dev/null & do_work >/dev/null & while load_policy; do echo -n .; sleep 0.1; done kill %1 kill %2 kill %3 ``` Fix this by allocating the temporary sidtab convert structures dynamically and passing them among the selinux_policy_{load,cancel,commit} functions. Fixes: 02a52c5c8c3b ("selinux: move policy commit after updating selinuxfs") Cc: stable@vger.kernel.org Tested-by: Tyler Hicks <tyhicks@linux.microsoft.com> Reviewed-by: Tyler Hicks <tyhicks@linux.microsoft.com> Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com> [PM: merge fuzz in security.h and services.c] Signed-off-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-30selinux: don't log MAC_POLICY_LOAD record on failed policy loadOndrej Mosnacek
commit 519dad3bcd809dc1523bf80ab0310ddb3bf00ade upstream. If sel_make_policy_nodes() fails, we should jump to 'out', not 'out1', as the latter would incorrectly log an MAC_POLICY_LOAD audit record, even though the policy hasn't actually been reloaded. The 'out1' jump label now becomes unused and can be removed. Fixes: 02a52c5c8c3b ("selinux: move policy commit after updating selinuxfs") Cc: stable@vger.kernel.org Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-04selinux: fix inconsistency between inode_getxattr and inode_listsecurityAmir Goldstein
commit a9ffe682c58aaff643764547f5420e978b6e0830 upstream. 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(). Match the logic of inode_listsecurity to that of inode_getxattr and do not list the security.selinux xattr if selinux is not initialized. 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/ Fixes: c8e222616c7e ("selinux: allow reading labels before policy is loaded") Cc: stable@vger.kernel.org#v5.9+ Signed-off-by: Amir Goldstein <amir73il@gmail.com> Reviewed-by: Ondrej Mosnacek <omosnace@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-12-30selinux: fix inode_doinit_with_dentry() LABEL_INVALID error handlingPaul Moore
[ Upstream commit 200ea5a2292dc444a818b096ae6a32ba3caa51b9 ] A previous fix, commit 83370b31a915 ("selinux: fix error initialization in inode_doinit_with_dentry()"), changed how failures were handled before a SELinux policy was loaded. Unfortunately that patch was potentially problematic for two reasons: it set the isec->initialized state without holding a lock, and it didn't set the inode's SELinux label to the "default" for the particular filesystem. The later can be a problem if/when a later attempt to revalidate the inode fails and SELinux reverts to the existing inode label. This patch should restore the default inode labeling that existed before the original fix, without affecting the LABEL_INVALID marking such that revalidation will still be attempted in the future. Fixes: 83370b31a915 ("selinux: fix error initialization in inode_doinit_with_dentry()") Reported-by: Sven Schnelle <svens@linux.ibm.com> Tested-by: Sven Schnelle <svens@linux.ibm.com> Reviewed-by: Ondrej Mosnacek <omosnace@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-12-30selinux: fix error initialization in inode_doinit_with_dentry()Tianyue Ren
[ Upstream commit 83370b31a915493231e5b9addc72e4bef69f8d31 ] Mark the inode security label as invalid if we cannot find a dentry so that we will retry later rather than marking it initialized with the unlabeled SID. Fixes: 9287aed2ad1f ("selinux: Convert isec->lock into a spinlock") Signed-off-by: Tianyue Ren <rentianyue@kylinos.cn> [PM: minor comment tweaks] Signed-off-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-11-14Merge tag 'selinux-pr-20201113' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux Pull selinux fix from Paul Moore: "One small SELinux patch to make sure we return an error code when an allocation fails. It passes all of our tests, but given the nature of the patch that isn't surprising" * tag 'selinux-pr-20201113' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux: selinux: Fix error return code in sel_ib_pkey_sid_slow()
2020-11-12selinux: Fix error return code in sel_ib_pkey_sid_slow()Chen Zhou
Fix to return a negative error code from the error handling case instead of 0 in function sel_ib_pkey_sid_slow(), as done elsewhere in this function. Cc: stable@vger.kernel.org Fixes: 409dcf31538a ("selinux: Add a cache for quicker retreival of PKey SIDs") Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: Chen Zhou <chenzhou10@huawei.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2020-10-15Merge tag 'char-misc-5.10-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc Pull char/misc driver updates from Greg KH: "Here is the big set of char, misc, and other assorted driver subsystem patches for 5.10-rc1. There's a lot of different things in here, all over the drivers/ directory. Some summaries: - soundwire driver updates - habanalabs driver updates - extcon driver updates - nitro_enclaves new driver - fsl-mc driver and core updates - mhi core and bus updates - nvmem driver updates - eeprom driver updates - binder driver updates and fixes - vbox minor bugfixes - fsi driver updates - w1 driver updates - coresight driver updates - interconnect driver updates - misc driver updates - other minor driver updates All of these have been in linux-next for a while with no reported issues" * tag 'char-misc-5.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (396 commits) binder: fix UAF when releasing todo list docs: w1: w1_therm: Fix broken xref, mistakes, clarify text misc: Kconfig: fix a HISI_HIKEY_USB dependency LSM: Fix type of id parameter in kernel_post_load_data prototype misc: Kconfig: add a new dependency for HISI_HIKEY_USB firmware_loader: fix a kernel-doc markup w1: w1_therm: make w1_poll_completion static binder: simplify the return expression of binder_mmap test_firmware: Test partial read support firmware: Add request_partial_firmware_into_buf() firmware: Store opt_flags in fw_priv fs/kernel_file_read: Add "offset" arg for partial reads IMA: Add support for file reads without contents LSM: Add "contents" flag to kernel_read_file hook module: Call security_kernel_post_load_data() firmware_loader: Use security_post_load_data() LSM: Introduce kernel_post_load_data() hook fs/kernel_read_file: Add file_size output argument fs/kernel_read_file: Switch buffer size arg to size_t fs/kernel_read_file: Remove redundant size argument ...
2020-10-13Merge tag 'selinux-pr-20201012' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux Pull selinux updates from Paul Moore: "A decent number of SELinux patches for v5.10, twenty two in total. The highlights are listed below, but all of the patches pass our test suite and merge cleanly. - A number of changes to how the SELinux policy is loaded and managed inside the kernel with the goal of improving the atomicity of a SELinux policy load operation. These changes account for the bulk of the diffstat as well as the patch count. A special thanks to everyone who contributed patches and fixes for this work. - Convert the SELinux policy read-write lock to RCU. - A tracepoint was added for audited SELinux access control events; this should help provide a more unified backtrace across kernel and userspace. - Allow the removal of security.selinux xattrs when a SELinux policy is not loaded. - Enable policy capabilities in SELinux policies created with the scripts/selinux/mdp tool. - Provide some "no sooner than" dates for the SELinux checkreqprot sysfs deprecation" * tag 'selinux-pr-20201012' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux: (22 commits) selinux: provide a "no sooner than" date for the checkreqprot removal selinux: Add helper functions to get and set checkreqprot selinux: access policycaps with READ_ONCE/WRITE_ONCE selinux: simplify away security_policydb_len() selinux: move policy mutex to selinux_state, use in lockdep checks selinux: fix error handling bugs in security_load_policy() selinux: convert policy read-write lock to RCU selinux: delete repeated words in comments selinux: add basic filtering for audit trace events selinux: add tracepoint on audited events selinux: Create new booleans and class dirs out of tree selinux: Standardize string literal usage for selinuxfs directory names selinux: Refactor selinuxfs directory populating functions selinux: Create function for selinuxfs directory cleanup selinux: permit removing security.selinux xattr before policy load selinux: fix memdup.cocci warnings selinux: avoid dereferencing the policy prior to initialization selinux: fix allocation failure check on newpolicy->sidtab selinux: refactor changing booleans selinux: move policy commit after updating selinuxfs ...
2020-10-05LSM: Add "contents" flag to kernel_read_file hookKees Cook
As with the kernel_load_data LSM hook, add a "contents" flag to the kernel_read_file LSM hook that indicates whether the LSM can expect a matching call to the kernel_post_read_file LSM hook with the full contents of the file. With the coming addition of partial file read support for kernel_read_file*() API, the LSM will no longer be able to always see the entire contents of a file during the read calls. For cases where the LSM must read examine the complete file contents, it will need to do so on its own every time the kernel_read_file hook is called with contents=false (or reject such cases). Adjust all existing LSMs to retain existing behavior. Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Mimi Zohar <zohar@linux.ibm.com> Link: https://lore.kernel.org/r/20201002173828.2099543-12-keescook@chromium.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-10-05LSM: Introduce kernel_post_load_data() hookKees Cook
There are a few places in the kernel where LSMs would like to have visibility into the contents of a kernel buffer that has been loaded or read. While security_kernel_post_read_file() (which includes the buffer) exists as a pairing for security_kernel_read_file(), no such hook exists to pair with security_kernel_load_data(). Earlier proposals for just using security_kernel_post_read_file() with a NULL file argument were rejected (i.e. "file" should always be valid for the security_..._file hooks, but it appears at least one case was left in the kernel during earlier refactoring. (This will be fixed in a subsequent patch.) Since not all cases of security_kernel_load_data() can have a single contiguous buffer made available to the LSM hook (e.g. kexec image segments are separately loaded), there needs to be a way for the LSM to reason about its expectations of the hook coverage. In order to handle this, add a "contents" argument to the "kernel_load_data" hook that indicates if the newly added "kernel_post_load_data" hook will be called with the full contents once loaded. That way, LSMs requiring full contents can choose to unilaterally reject "kernel_load_data" with contents=false (which is effectively the existing hook coverage), but when contents=true they can allow it and later evaluate the "kernel_post_load_data" hook once the buffer is loaded. With this change, LSMs can gain coverage over non-file-backed data loads (e.g. init_module(2) and firmware userspace helper), which will happen in subsequent patches. Additionally prepare IMA to start processing these cases. Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: KP Singh <kpsingh@google.com> Link: https://lore.kernel.org/r/20201002173828.2099543-9-keescook@chromium.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-10-05fs/kernel_read_file: Split into separate include fileScott Branden
Move kernel_read_file* out of linux/fs.h to its own linux/kernel_read_file.h include file. That header gets pulled in just about everywhere and doesn't really need functions not related to the general fs interface. Suggested-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Scott Branden <scott.branden@broadcom.com> Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Mimi Zohar <zohar@linux.ibm.com> Reviewed-by: Luis Chamberlain <mcgrof@kernel.org> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: James Morris <jamorris@linux.microsoft.com> Link: https://lore.kernel.org/r/20200706232309.12010-2-scott.branden@broadcom.com Link: https://lore.kernel.org/r/20201002173828.2099543-4-keescook@chromium.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-09-15selinux: Add helper functions to get and set checkreqprotLakshmi Ramasubramanian
checkreqprot data member in selinux_state struct is accessed directly by SELinux functions to get and set. This could cause unexpected read or write access to this data member due to compiler optimizations and/or compiler's reordering of access to this field. Add helper functions to get and set checkreqprot data member in selinux_state struct. These helper functions use READ_ONCE and WRITE_ONCE macros to ensure atomic read or write of memory for this data member. Signed-off-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com> Suggested-by: Stephen Smalley <stephen.smalley.work@gmail.com> Suggested-by: Paul Moore <paul@paul-moore.com> Acked-by: Stephen Smalley <stephen.smalley.work@gmail.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2020-09-11selinux: access policycaps with READ_ONCE/WRITE_ONCEStephen Smalley
Use READ_ONCE/WRITE_ONCE for all accesses to the selinux_state.policycaps booleans to prevent compiler mischief. Signed-off-by: Stephen Smalley <stephen.smalley.work@gmail.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2020-08-31selinux: simplify away security_policydb_len()Ondrej Mosnacek
Remove the security_policydb_len() calls from sel_open_policy() and instead update the inode size from the size returned from security_read_policy(). Since after this change security_policydb_len() is only called from security_load_policy(), remove it entirely and just open-code it there. Also, since security_load_policy() is always called with policy_mutex held, make it dereference the policy pointer directly and drop the unnecessary RCU locking. Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com> Acked-by: Stephen Smalley <stephen.smalley.work@gmail.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2020-08-27selinux: move policy mutex to selinux_state, use in lockdep checksStephen Smalley
Move the mutex used to synchronize policy changes (reloads and setting of booleans) from selinux_fs_info to selinux_state and use it in lockdep checks for rcu_dereference_protected() calls in the security server functions. This makes the dependency on the mutex explicit in the code rather than relying on comments. Signed-off-by: Stephen Smalley <stephen.smalley.work@gmail.com> Reviewed-by: Ondrej Mosnacek <omosnace@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2020-08-26selinux: fix error handling bugs in security_load_policy()Dan Carpenter
There are a few bugs in the error handling for security_load_policy(). 1) If the newpolicy->sidtab allocation fails then it leads to a NULL dereference. Also the error code was not set to -ENOMEM on that path. 2) If policydb_read() failed then we call policydb_destroy() twice which meands we call kvfree(p->sym_val_to_name[i]) twice. 3) If policydb_load_isids() failed then we call sidtab_destroy() twice and that results in a double free in the sidtab_destroy_tree() function because entry.ptr_inner and entry.ptr_leaf are not set to NULL. One thing that makes this code nice to deal with is that none of the functions return partially allocated data. In other words, the policydb_read() either allocates everything successfully or it frees all the data it allocates. It never returns a mix of allocated and not allocated data. I re-wrote this to only free the successfully allocated data which avoids the double frees. I also re-ordered selinux_policy_free() so it's in the reverse order of the allocation function. Fixes: c7c556f1e81b ("selinux: refactor changing booleans") Acked-by: Stephen Smalley <stephen.smalley.work@gmail.com> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> [PM: partially merged by hand due to merge fuzz] Signed-off-by: Paul Moore <paul@paul-moore.com>
2020-08-25selinux: convert policy read-write lock to RCUStephen Smalley
Convert the policy read-write lock to RCU. This is significantly simplified by the earlier work to encapsulate the policy data structures and refactor the policy load and boolean setting logic. Move the latest_granting sequence number into the selinux_policy structure so that it can be updated atomically with the policy. Since removing the policy rwlock and moving latest_granting reduces the selinux_ss structure to nothing more than a wrapper around the selinux_policy pointer, get rid of the extra layer of indirection. At present this change merely passes a hardcoded 1 to rcu_dereference_check() in the cases where we know we do not need to take rcu_read_lock(), with the preceding comment explaining why. Alternatively we could pass fsi->mutex down from selinuxfs and apply a lockdep check on it instead. Based in part on earlier attempts to convert the policy rwlock to RCU by Kaigai Kohei [1] and by Peter Enderborg [2]. [1] https://lore.kernel.org/selinux/6e2f9128-e191-ebb3-0e87-74bfccb0767f@tycho.nsa.gov/ [2] https://lore.kernel.org/selinux/20180530141104.28569-1-peter.enderborg@sony.com/ Signed-off-by: Stephen Smalley <stephen.smalley.work@gmail.com> Reviewed-by: Ondrej Mosnacek <omosnace@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2020-08-24selinux: delete repeated words in commentsRandy Dunlap
Drop a repeated word in comments. {open, is, then} Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Paul Moore <paul@paul-moore.com> Cc: Stephen Smalley <stephen.smalley.work@gmail.com> Cc: Eric Paris <eparis@parisplace.org> Cc: selinux@vger.kernel.org Cc: James Morris <jmorris@namei.org> Cc: "Serge E. Hallyn" <serge@hallyn.com> Cc: linux-security-module@vger.kernel.org [PM: fix subject line] Signed-off-by: Paul Moore <paul@paul-moore.com>
2020-08-23treewide: Use fallthrough pseudo-keywordGustavo A. R. Silva
Replace the existing /* fall through */ comments and its variants with the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary fall-through markings when it is the case. [1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
2020-08-21selinux: add basic filtering for audit trace eventsPeter Enderborg
This patch adds further attributes to the event. These attributes are helpful to understand the context of the message and can be used to filter the events. There are three common items. Source context, target context and tclass. There are also items from the outcome of operation performed. An event is similar to: <...>-1309 [002] .... 6346.691689: selinux_audited: requested=0x4000000 denied=0x4000000 audited=0x4000000 result=-13 scontext=system_u:system_r:cupsd_t:s0-s0:c0.c1023 tcontext=system_u:object_r:bin_t:s0 tclass=file With systems where many denials are occurring, it is useful to apply a filter. The filtering is a set of logic that is inserted with the filter file. Example: echo "tclass==\"file\" " > events/avc/selinux_audited/filter This adds that we only get tclass=file. The trace can also have extra properties. Adding the user stack can be done with echo 1 > options/userstacktrace Now the output will be runcon-1365 [003] .... 6960.955530: selinux_audited: requested=0x4000000 denied=0x4000000 audited=0x4000000 result=-13 scontext=system_u:system_r:cupsd_t:s0-s0:c0.c1023 tcontext=system_u:object_r:bin_t:s0 tclass=file runcon-1365 [003] .... 6960.955560: <user stack trace> => <00007f325b4ce45b> => <00005607093efa57> Signed-off-by: Peter Enderborg <peter.enderborg@sony.com> Reviewed-by: Thiébaud Weksteen <tweek@google.com> Acked-by: Stephen Smalley <stephen.smalley.work@gmail.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2020-08-21selinux: add tracepoint on audited eventsThiébaud Weksteen
The audit data currently captures which process and which target is responsible for a denial. There is no data on where exactly in the process that call occurred. Debugging can be made easier by being able to reconstruct the unified kernel and userland stack traces [1]. Add a tracepoint on the SELinux denials which can then be used by userland (i.e. perf). Although this patch could manually be added by each OS developer to trouble shoot a denial, adding it to the kernel streamlines the developers workflow. It is possible to use perf for monitoring the event: # perf record -e avc:selinux_audited -g -a ^C # perf report -g [...] 6.40% 6.40% audited=800000 tclass=4 | __libc_start_main | |--4.60%--__GI___ioctl | entry_SYSCALL_64 | do_syscall_64 | __x64_sys_ioctl | ksys_ioctl | binder_ioctl | binder_set_nice | can_nice | capable | security_capable | cred_has_capability.isra.0 | slow_avc_audit | common_lsm_audit | avc_audit_post_callback | avc_audit_post_callback | It is also possible to use the ftrace interface: # echo 1 > /sys/kernel/debug/tracing/events/avc/selinux_audited/enable # cat /sys/kernel/debug/tracing/trace tracer: nop entries-in-buffer/entries-written: 1/1 #P:8 [...] dmesg-3624 [001] 13072.325358: selinux_denied: audited=800000 tclass=4 The tclass value can be mapped to a class by searching security/selinux/flask.h. The audited value is a bit field of the permissions described in security/selinux/av_permissions.h for the corresponding class. [1] https://source.android.com/devices/tech/debug/native_stack_dump Signed-off-by: Thiébaud Weksteen <tweek@google.com> Suggested-by: Joel Fernandes <joelaf@google.com> Reviewed-by: Peter Enderborg <peter.enderborg@sony.com> Acked-by: Stephen Smalley <stephen.smalley.work@gmail.com> Signed-off-by: Paul Moore <paul@paul-moore.com>