CVE-2026-99169
In the Linux kernel, the following vulnerability has been resolved: futex: Fix mm reuse handling for FUT_OFF_MMSHARED A FUT_OFF_MMSHARED futex is a shared futex that refers to an MM. It is possible for a process to wait on a shared futex with a different MM because a FUT_OFF_INODE waiter can be requeued onto a FUT_OFF_MMSHARED futex by another process. This can cause FUT_OFF_MMSHARED waiters on a freed MM to consume wakeups intended for a newly allocated MM at the same address. Fix it by keying FUT_OFF_MMSHARED using a unique 64-bit per-MM ID. Leave private futexes as before to avoid influencing the performance of the hotpath. (Multi-threaded processes typically implicitly use FUT_OFF_MMSHARED by setting clear_child_tid such that it points into anonymous memory, which causes mm_release() in a multi-threaded mm to perform FUTEX_WAKE.)
- Status
- Received - 416baaa9-dc9f-4396-8d5f-8c081fb06d67
- Published
- 2026-10-28
- Last modified
- 2026-10-28
Affected products
References
- https://git.kernel.org/stable/c/c17cc2027773e8e4913c5ab0fe3a489b1ed5bf81
- https://git.kernel.org/stable/c/2855ddc6844f527e375e78afb55ec2a5182f23b3
- https://git.kernel.org/stable/c/3267512ad1c2cc0c7768c5b014dc2cceb398a801
