In the Linux kernel, the following vulnerability has been resolved:
futex/pi: Plug private futex exec() race
The check for private futexes whether the waiter's mm, which is stored in
the futex_key and copied into the pi_state, is the same as the owner's mm
is not sufficient for exec(). exec() has a gap where the mm check fails to
give the correct answer:
exec()
...
exec_release_mm()
futex_exec_release()
tsk::futex::exit_state = EXITING;
cleanup_robust_list();
1) tsk::futex::exit_state = OK;
...
old_mm = tsk::mm;
2) tsk::mm = ->mm;
Between #1 and #2 the check for the mm is wrong as that mm is about to be
swapped out and eventually freed.
Plug this gap by:
1) Setting tsk::futex::exit_state to FUTEX_STATE_DEAD in
futex_exec_release()
2) Setting tsk::futex::exit_state to FUTEX_STATE_OK after
the mm has been switched.
From a futex point of view the task is dead after it finished the robust
list cleanup up to the point where it sets the state to OK again.
futex/pi: Plug private futex exec() race
The check for private futexes whether the waiter's mm, which is stored in
the futex_key and copied into the pi_state, is the same as the owner's mm
is not sufficient for exec(). exec() has a gap where the mm check fails to
give the correct answer:
exec()
...
exec_release_mm()
futex_exec_release()
tsk::futex::exit_state = EXITING;
cleanup_robust_list();
1) tsk::futex::exit_state = OK;
...
old_mm = tsk::mm;
2) tsk::mm = ->mm;
Between #1 and #2 the check for the mm is wrong as that mm is about to be
swapped out and eventually freed.
Plug this gap by:
1) Setting tsk::futex::exit_state to FUTEX_STATE_DEAD in
futex_exec_release()
2) Setting tsk::futex::exit_state to FUTEX_STATE_OK after
the mm has been switched.
From a futex point of view the task is dead after it finished the robust
list cleanup up to the point where it sets the state to OK again.
Metrics
Affected Vendors & Products
Advisories
No advisories yet.
Fixes
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
References
History
Fri, 04 Sep 2026 15:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: futex/pi: Plug private futex exec() race The check for private futexes whether the waiter's mm, which is stored in the futex_key and copied into the pi_state, is the same as the owner's mm is not sufficient for exec(). exec() has a gap where the mm check fails to give the correct answer: exec() ... exec_release_mm() futex_exec_release() tsk::futex::exit_state = EXITING; cleanup_robust_list(); 1) tsk::futex::exit_state = OK; ... old_mm = tsk::mm; 2) tsk::mm = ->mm; Between #1 and #2 the check for the mm is wrong as that mm is about to be swapped out and eventually freed. Plug this gap by: 1) Setting tsk::futex::exit_state to FUTEX_STATE_DEAD in futex_exec_release() 2) Setting tsk::futex::exit_state to FUTEX_STATE_OK after the mm has been switched. From a futex point of view the task is dead after it finished the robust list cleanup up to the point where it sets the state to OK again. | |
| Title | futex/pi: Plug private futex exec() race | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
Projects
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MITRE
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-09-04T15:12:49.215Z
Reserved: 2026-08-26T14:34:25.792Z
Link: CVE-2026-80777
Vulnrichment
No data.
NVD
Status : Received
Published: 2026-09-04T16:18:03.373
Modified: 2026-09-04T16:18:03.373
Link: CVE-2026-80777
Redhat
No data.
OpenCVE Enrichment
No data.
Weaknesses
No weakness.