kernel/linux.git/security/selinux, branch v6.6.131

selinux: fix selinux_xfrm_alloc_user() to set correct ctx_len

2025-06-27T10:08:59+00:00

commit 86c8db86af43f52f682e53a0f2f0828683be1e52 upstream. We should count the terminating NUL byte as part of the ctx_len. Otherwise, UBSAN logs a warning: UBSAN: array-index-out-of-bounds in security/selinux/xfrm.c:99:14 index 60 is out of range for type 'char [*]' The allocation itself is correct so there is no actual out of bounds indexing, just a warning. Cc: stable@vger.kernel.org Suggested-by: Christian Göttsche Link: https://lore.kernel.org/selinux/CAEjxPJ6tA5+LxsGfOJokzdPeRomBHjKLBVR6zbrg+_w3ZZbM3A@mail.gmail.com/ Signed-off-by: Stephen Smalley Signed-off-by: Paul Moore Signed-off-by: Greg Kroah-Hartman

selinux: ignore unknown extended permissions

2025-01-09T12:31:54+00:00

commit 900f83cf376bdaf798b6f5dcb2eae0c822e908b6 upstream. When evaluating extended permissions, ignore unknown permissions instead of calling BUG(). This commit ensures that future permissions can be added without interfering with older kernels. Cc: stable@vger.kernel.org Fixes: fa1aa143ac4a ("selinux: extended permissions for ioctls") Signed-off-by: Thiébaud Weksteen Signed-off-by: Paul Moore Acked-by: Paul Moore Signed-off-by: Greg Kroah-Hartman

selinux: improve error checking in sel_write_load()

2024-11-01T00:58:33+00:00

[ Upstream commit 42c773238037c90b3302bf37a57ae3b5c3f6004a ] Move our existing input sanity checking to the top of sel_write_load() and add a check to ensure the buffer size is non-zero. Move a local variable initialization from the declaration to before it is used. Minor style adjustments. Reported-by: Sam Sun Signed-off-by: Paul Moore Signed-off-by: Thadeu Lima de Souza Cascardo Signed-off-by: Sasha Levin

selinux,smack: don't bypass permissions check in inode_setsecctx hook

2024-09-04T11:28:24+00:00

commit 76a0e79bc84f466999fa501fce5bf7a07641b8a7 upstream. Marek Gresko reports that the root user on an NFS client is able to change the security labels on files on an NFS filesystem that is exported with root squashing enabled. The end of the kerneldoc comment for __vfs_setxattr_noperm() states: * This function requires the caller to lock the inode's i_mutex before it * is executed. It also assumes that the caller will make the appropriate * permission checks. nfsd_setattr() does do permissions checking via fh_verify() and nfsd_permission(), but those don't do all the same permissions checks that are done by security_inode_setxattr() and its related LSM hooks do. Since nfsd_setattr() is the only consumer of security_inode_setsecctx(), simplest solution appears to be to replace the call to __vfs_setxattr_noperm() with a call to __vfs_setxattr_locked(). This fixes the above issue and has the added benefit of causing nfsd to recall conflicting delegations on a file when a client tries to change its security label. Cc: stable@kernel.org Reported-by: Marek Gresko Link: https://bugzilla.kernel.org/show_bug.cgi?id=218809 Signed-off-by: Scott Mayhew Tested-by: Stephen Smalley Reviewed-by: Stephen Smalley Reviewed-by: Chuck Lever Reviewed-by: Jeff Layton Acked-by: Casey Schaufler Signed-off-by: Paul Moore Signed-off-by: Greg Kroah-Hartman

selinux: add the processing of the failure of avc_add_xperms_decision()

2024-08-29T15:33:15+00:00

commit 6dd1e4c045afa6a4ba5d46f044c83bd357c593c2 upstream. When avc_add_xperms_decision() fails, the information recorded by the new avc node is incomplete. In this case, the new avc node should be released instead of replacing the old avc node. Cc: stable@vger.kernel.org Fixes: fa1aa143ac4a ("selinux: extended permissions for ioctls") Suggested-by: Stephen Smalley Signed-off-by: Zhen Lei Acked-by: Stephen Smalley Signed-off-by: Paul Moore Signed-off-by: Greg Kroah-Hartman

selinux: fix potential counting error in avc_add_xperms_decision()

2024-08-29T15:33:15+00:00

commit 379d9af3f3da2da1bbfa67baf1820c72a080d1f1 upstream. The count increases only when a node is successfully added to the linked list. Cc: stable@vger.kernel.org Fixes: fa1aa143ac4a ("selinux: extended permissions for ioctls") Signed-off-by: Zhen Lei Acked-by: Stephen Smalley Signed-off-by: Paul Moore Signed-off-by: Greg Kroah-Hartman

selinux: revert our use of vma_is_initial_heap()

2024-08-29T15:33:11+00:00

commit 05a3d6e9307250a5911d75308e4363466794ab21 upstream. Unfortunately it appears that vma_is_initial_heap() is currently broken for applications that do not currently have any heap allocated, e.g. brk == start_brk. The breakage is such that it will cause SELinux to check for the process/execheap permission on memory regions that cross brk/start_brk even when there is no heap. The proper fix would be to correct vma_is_initial_heap(), but as there are multiple callers I am hesitant to unilaterally modify the helper out of concern that I would end up breaking some other subsystem. The mm developers have been made aware of the situation and hopefully they will have a fix at some point in the future, but we need a fix soon so we are simply going to revert our use of vma_is_initial_heap() in favor of our old logic/code which works as expected, even in the face of a zero size heap. We can return to using vma_is_initial_heap() at some point in the future when it is fixed. Cc: stable@vger.kernel.org Reported-by: Marc Reisner Closes: https://lore.kernel.org/all/ZrPmoLKJEf1wiFmM@marcreisner.com Fixes: 68df1baf158f ("selinux: use vma_is_initial_stack() and vma_is_initial_heap()") Signed-off-by: Paul Moore Signed-off-by: Greg Kroah-Hartman

ima: Avoid blocking in RCU read-side critical section

2024-07-11T10:49:18+00:00

commit 9a95c5bfbf02a0a7f5983280fe284a0ff0836c34 upstream. A panic happens in ima_match_policy: BUG: unable to handle kernel NULL pointer dereference at 0000000000000010 PGD 42f873067 P4D 0 Oops: 0000 [#1] SMP NOPTI CPU: 5 PID: 1286325 Comm: kubeletmonit.sh Kdump: loaded Tainted: P Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 0.0.0 02/06/2015 RIP: 0010:ima_match_policy+0x84/0x450 Code: 49 89 fc 41 89 cf 31 ed 89 44 24 14 eb 1c 44 39 7b 18 74 26 41 83 ff 05 74 20 48 8b 1b 48 3b 1d f2 b9 f4 00 0f 84 9c 01 00 00 <44> 85 73 10 74 ea 44 8b 6b 14 41 f6 c5 01 75 d4 41 f6 c5 02 74 0f RSP: 0018:ff71570009e07a80 EFLAGS: 00010207 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000200 RDX: ffffffffad8dc7c0 RSI: 0000000024924925 RDI: ff3e27850dea2000 RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffffabfce739 R10: ff3e27810cc42400 R11: 0000000000000000 R12: ff3e2781825ef970 R13: 00000000ff3e2785 R14: 000000000000000c R15: 0000000000000001 FS: 00007f5195b51740(0000) GS:ff3e278b12d40000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000010 CR3: 0000000626d24002 CR4: 0000000000361ee0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: ima_get_action+0x22/0x30 process_measurement+0xb0/0x830 ? page_add_file_rmap+0x15/0x170 ? alloc_set_pte+0x269/0x4c0 ? prep_new_page+0x81/0x140 ? simple_xattr_get+0x75/0xa0 ? selinux_file_open+0x9d/0xf0 ima_file_check+0x64/0x90 path_openat+0x571/0x1720 do_filp_open+0x9b/0x110 ? page_counter_try_charge+0x57/0xc0 ? files_cgroup_alloc_fd+0x38/0x60 ? __alloc_fd+0xd4/0x250 ? do_sys_open+0x1bd/0x250 do_sys_open+0x1bd/0x250 do_syscall_64+0x5d/0x1d0 entry_SYSCALL_64_after_hwframe+0x65/0xca Commit c7423dbdbc9e ("ima: Handle -ESTALE returned by ima_filter_rule_match()") introduced call to ima_lsm_copy_rule within a RCU read-side critical section which contains kmalloc with GFP_KERNEL. This implies a possible sleep and violates limitations of RCU read-side critical sections on non-PREEMPT systems. Sleeping within RCU read-side critical section might cause synchronize_rcu() returning early and break RCU protection, allowing a UAF to happen. The root cause of this issue could be described as follows: | Thread A | Thread B | | |ima_match_policy | | | rcu_read_lock | |ima_lsm_update_rule | | | synchronize_rcu | | | | kmalloc(GFP_KERNEL)| | | sleep | ==> synchronize_rcu returns early | kfree(entry) | | | | entry = entry->next| ==> UAF happens and entry now becomes NULL (or could be anything). | | entry->action | ==> Accessing entry might cause panic. To fix this issue, we are converting all kmalloc that is called within RCU read-side critical section to use GFP_ATOMIC. Fixes: c7423dbdbc9e ("ima: Handle -ESTALE returned by ima_filter_rule_match()") Cc: stable@vger.kernel.org Signed-off-by: GUO Zihua Acked-by: John Johansen Reviewed-by: Mimi Zohar Reviewed-by: Casey Schaufler [PM: fixed missing comment, long lines, !CONFIG_IMA_LSM_RULES case] Signed-off-by: Paul Moore Signed-off-by: Mimi Zohar Signed-off-by: Greg Kroah-Hartman

selinux: avoid dereference of garbage after mount failure

2024-04-10T14:35:48+00:00

commit 37801a36b4d68892ce807264f784d818f8d0d39b upstream. In case kern_mount() fails and returns an error pointer return in the error branch instead of continuing and dereferencing the error pointer. While on it drop the never read static variable selinuxfs_mount. Cc: stable@vger.kernel.org Fixes: 0619f0f5e36f ("selinux: wrap selinuxfs state") Signed-off-by: Christian Göttsche Signed-off-by: Paul Moore Signed-off-by: Greg Kroah-Hartman

lsm: new security_file_ioctl_compat() hook

2024-02-01T00:18:54+00:00

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 Reviewed-by: Stephen Smalley [PM: subject tweak, line length fixes, and alignment corrections] Signed-off-by: Paul Moore Signed-off-by: Greg Kroah-Hartman