Description (CNA)
In the Linux kernel, the following vulnerability has been resolved: perf: Fix event leak upon exit When a task is scheduled out, pending sigtrap deliveries are deferred to the target task upon resume to userspace via task_work. However failures while adding an event's callback to the task_work engine are ignored. And since the last call for events exit happen after task work is eventually closed, there is a small window during which pending sigtrap can be queued though ignored, leaking the event refcount addition such as in the following scenario: TASK A ----- do_exit() exit_task_work(tsk); <IRQ> perf_event_overflow() event->pending_sigtrap = pending_id; irq_work_queue(&event->pending_irq); </IRQ> =========> PREEMPTION: TASK A -> TASK B event_sched_out() event->pending_sigtrap = 0; atomic_long_inc_not_zero(&event->refcount) // FAILS: task work has exited task_work_add(&event->pending_task) [...] <IRQ WORK> perf_pending_irq() // early return: event->oncpu = -1 </IRQ WORK> [...] =========> TASK B -> TASK A perf_event_exit_task(tsk) perf_event_exit_event() free_event() WARN(atomic_long_cmpxchg(&event->refcount, 1, 0) != 1) // leak event due to unexpected refcount == 2 As a result the event is never released while the task exits. Fix this with appropriate task_work_add()'s error handling.
Affected (CNA)
| Vendor / product | Versions |
|---|---|
| Linux / Linux | affected 8bffa95ac19ff27c8261904f89d36c7fcf215d59 before 67fad724f1b568b356c1065d50df46e6b30eb2f7; affected 517e6a301f34613bff24a8e35b5455884f2d83d8 before 70882d7fa74f0731492a0d493e8515a4f7131831; affected 517e6a301f34613bff24a8e35b5455884f2d83d8 before 05d3fd599594abf79aad4484bccb2b26e1cb0b51; affected 517e6a301f34613bff24a8e35b5455884f2d83d8 before 3d7a63352a93bdb8a1cdf29606bf617d3ac1c22a; affected 517e6a301f34613bff24a8e35b5455884f2d83d8 before 2fd5ad3f310de22836cdacae919dd99d758a1f1b; affected 78e1317a174edbfd1182599bf76c092a2877672c; affected 5.15.84 before 5.15.165; affected 6.0.14 before 6.1 |
| Linux / Linux | affected 6.1; unaffected 0 before 6.1; unaffected 5.15.165 through 5.15.*; unaffected 6.1.103 through 6.1.*; unaffected 6.6.44 through 6.6.*; unaffected 6.10.3 through 6.10.*; unaffected 6.11 through * |
CWE
No CWE identifiers supplied.
References
- https://git.kernel.org/stable/c/67fad724f1b568b356c1065d50df46e6b30eb2f7
- https://git.kernel.org/stable/c/70882d7fa74f0731492a0d493e8515a4f7131831
- https://git.kernel.org/stable/c/05d3fd599594abf79aad4484bccb2b26e1cb0b51
- https://git.kernel.org/stable/c/3d7a63352a93bdb8a1cdf29606bf617d3ac1c22a
- https://git.kernel.org/stable/c/2fd5ad3f310de22836cdacae919dd99d758a1f1b
ADP enrichment
No English description supplied.
No references supplied.
No English description supplied.