CVE-2026-97961 perf/core: Allow list_del during perf_event_overflow()
A local attacker can trigger list corruption in the Linux kernel perf subsystem, potentially causing a denial of service or privilege escalation.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-97961?
CVE-2026-97961 is an use after free vulnerability in Linux, published on 25 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
perf/core: Allow list_del during perf_event_overflow()
A PMU might use perf_sched_cb_inc() and perf_sched_cb_dec() interface to get the PMU call back function pmu::sched_task invoked at schedule in and schedule out. This is achieved by walking along the list anchored by sched_cb_list.
The following scenario might lead to a list corruption.
perf_pmu_sched_task() for_each_list_entry(..., &sched_cb_list) +--> __perf_pmu_sched_task() +--> event->pmu->sched_task()) +--> PMU_push_sample() +--> perf_event_overflow() +--> __perf_event_overflow() +--> pmu->stop() +--> perf_sched_cb_dec() remove entry from sched_cb_list while list node in use.
This happens when ioctl(fd, PERF_EVENT_IOC_REFRESH, xxx) has been invoked and perf_event::event_limit hits zero.
Prevent the list corruption and convert for_each_list_entry() to for_each_list_entry_safe().
Which versions are affected by CVE-2026-97961?
How do I fix CVE-2026-97961?
Apply the vendor's patch.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2026-97961 being exploited?
There is no known exploitation of CVE-2026-97961 in the wild and no public exploit code.
Sources
Also known as AZL-104247, BELL-CVE-2026-97961, DEBIAN-CVE-2026-97961, GHSA-prpp-c3xm-jcfh, UBUNTU-CVE-2026-97961.