perf: Make sure to use pmu_ctx->pmu for groups

Summary

In the Linux kernel, the following vulnerability has been resolved: perf: Make sure to use pmu_ctx->pmu for groups Oliver reported that x86_pmu_del() ended up doing an out-of-bound memory access when group_sched_in() fails and needs to roll back. This should be handled by the transaction callbacks, but he found that when the group leader is a software event, the transaction handlers of the wrong PMU are used. Despite the move_group case in perf_event_open() and group_sched_in() using pmu_ctx->pmu. Turns out, inherit uses event->pmu to clone the events, effectively undoing the move_group case for all inherited contexts. Fix this by also making inherit use pmu_ctx->pmu, ensuring all inherited counters end up in the same pmu context. Similarly, __perf_event_read() should use equally use pmu_ctx->pmu for the group case.

Timeline

1. Apr 22, 2026, 1:54 PM UTCCVE published
2. Oct 16, 2026, 3:10 PM UTCCISA SSVC assessment

   Exploitation: none · Automatable: no · Technical impact: total

3. Oct 19, 2026, 6:45 PM UTCRecord last updated

Affected versions

• Linux Linux

  From bd27568117664b8b3e259721393df420ed51f57b · fixed in 656f35b463995bee024d948440128230aacd81e1; From bd27568117664b8b3e259721393df420ed51f57b · fixed in 3a696e84a8b1fafdd774bb30d62919faf844d9e4; From bd27568117664b8b3e259721393df420ed51f57b · fixed in 35f7914e54fe7f13654c22ee045b05e4b6d8062b; From bd27568117664b8b3e259721393df420ed51f57b · fixed in 4c759446046500a1a6785b25725725c3ff087ace; From bd27568117664b8b3e259721393df420ed51f57b · fixed in 4b9ce671960627b2505b3f64742544ae9801df97

• Linux Linux

  6.2

• KernelLinux

  From 6.2.0 · fixed in 6.6.131; From 6.7.0 · fixed in 6.12.80; From 6.13.0 · fixed in 6.18.21; From 6.19.0 · fixed in 6.19.11

References 5