CVE-2026-68096

Status: UPDATED  |  Advisory ID: CVE-2026-68096

Key Details

Affected Products, Subsystems & Sectors

What to Know

In the Linux kernel, the following vulnerability has been resolved:

audit: fix recursive locking deadlock in audit_dupe_exe()

A deadlock occurs in the audit subsystem when duplicating

executable-related rules.

When a file is moved (e.g., via do_renameat2()), the VFS layer locks

the parent directory (I_MUTEX_PARENT), which synchronously triggers an

fsnotify_move event. If an existing executable audit rule matches the

file being moved, the audit subsystem catches this event and calls

audit_dupe_exe() to duplicate the watch and update the rule. Then,

audit_alloc_mark() would call kern_path_parent() to resolve the path,

leading to a blind attempt to acquire the exact same I_MUTEX_PARENT lock

already held by the task, resulting in the following recursive locking

deadlock:

============================================

WARNING: possible recursive locking detected

6.12.0-55.27.1.el10_0.x86_64+debug #1 Not tainted

--------------------------------------------

mv/5099 is trying to acquire lock:

ffff888132845358 (&inode->i_sb->s_type->i_mutex_dir_key/1){+.+.}-{3:3},

at: __kern_path_locked+0x10a/0x2f0

but task is already holding lock:

ffff888132846b58 (&inode->i_sb->s_type->i_mutex_dir_key/1){+.+.}-{3:3},

at: lock_two_directories+0x13f/0x2b0

other info that might help us debug this:

Possible unsafe locking scenario:

CPU0

----

lock(&inode->i_sb->s_type->i_mutex_dir_key/1);

lock(&inode->i_sb->s_type->i_mutex_dir_key/1);

*** DEADLOCK ***

May be due to missing lock nesting notation

6 locks held by mv/5099:

#0: ffff888112a9c440 (sb_writers#13)

at: do_renameat2+0x34c/0xbc0

#1: ffff888112a9c790 (&type->s_vfs_rename_key#3)

at: do_renameat2+0x415/0xbc0

#2: ffff888132846b58 (&inode->i_sb->s_type->i_mutex_dir_key/1)

at: lock_two_directories+0x13f/0x2b0

#3: ffff888132845358 (&inode->i_sb->s_type->i_mutex_dir_key/5)

at: lock_two_directories+0x175/0x2b0

#4: ffffffffb3a1fb10 (&fsnotify_mark_srcu)

at: fsnotify+0x454/0x28a0

#5: ffffffffaf886230 (audit_filter_mutex)

at: audit_update_watch+0x36/0x11e0

stack backtrace:

Call Trace:

<TASK>

dump_stack_lvl+0x6f/0xb0

print_deadlock_bug.cold+0xbd/0xca

validate_chain+0x83a/0xf00

__lock_acquire+0xcac/0x1d20

lock_acquire.part.0+0x11b/0x360

down_write_nested+0x9f/0x230

__kern_path_locked+0x10a/0x2f0

kern_path_locked+0x26/0x40

audit_alloc_mark+0xfb/0x4f0

audit_dupe_exe+0x6c/0xe0

audit_dupe_rule+0x6c2/0xc00

audit_update_watch+0x4cc/0x11e0

audit_watch_handle_event+0x12c/0x1b0

send_to_group+0x5d0/0x8b0

fsnotify+0x615/0x28a0

fsnotify_move+0x1d8/0x630

vfs_rename+0xdcd/0x1df0

do_renameat2+0x9d4/0xbc0

__x64_sys_renameat+0x192/0x260

do_syscall_64+0x92/0x180

entry_SYSCALL_64_after_hwframe+0x76/0x7e

RIP: 0033:0x7f0491fe8c4e

Code: 0f 1f 40 00 48 8b 15 c1 e1 16 00 f7 d8 64 89 02 b8 ff ff ff ff

c3 66 0f 1f 44 00 00 f3 0f 1e fa 49 89 ca b8 08 01 00 00 0f 05 <48>

3d 00 f0 ff ff 77 0a c3 66 0f 1f 84 00 00 00 00 00 48 8b 15 89

RSP: 002b:00007ffc7210bf38 EFLAGS: 00000246 ORIG_RAX: 0000000000000108

RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f0491fe8c4e

RDX: 0000000000000003 RSI: 00007ffc7210e6c8 RDI: 00000000ffffff9c

RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000001

R10: 00005575eb2dae2a R11: 0000000000000246 R12: 00005575eb2dae2a

R13: 00007ffc7210e6c8 R14: 0000000000000003 R15: 00000000ffffff9c

</TASK>

The aforementioned deadlock can be consistently reproduced by running

the script below:

audit-dupe-exe-deadlock.sh

--------------------------

#!/bin/bash

auditctl -D

mkdir -p /tmp/foo

touch /tmp/file

auditctl -a always,exit -F exe=/tmp/file -F path=/tmp/file -S all -k dr

mv /tmp/file /tmp/foo/file

rm -Rf /tmp/foo

This patch fixes the issue by introducing struct audit_watch_ctx to pass

the fsnotify event context down to audit_alloc_mark(). By utilizing the

already-resolved directory inode provided by the event, we bypass the

kern_path_parent() path resol

---truncated--- (NVD)

What to Do

Monitor Linux's web page for any future patch releases.

References