cbcvebase.
CVE-2025-40327
published 2025-12-09

CVE-2025-40327: In the Linux kernel, the following vulnerability has been resolved: perf/core: Fix system hang caused by cpu-clock usage cpu-clock usage by the async-profiler…

PriorityP421medium6.5
EPSS
0.21%
10.9th percentile
In the Linux kernel, the following vulnerability has been resolved: perf/core: Fix system hang caused by cpu-clock usage cpu-clock usage by the async-profiler tool can trigger a system hang, which got bisected back to the following commit by Octavia Togami: 18dbcbfabfff ("perf: Fix the POLL_HUP delivery breakage") causes this issue The root cause of the hang is that cpu-clock is a special type of SW event which relies on hrtimers. The __perf_event_overflow() callback is invoked from the hrtimer handler for cpu-clock events, and __perf_event_overflow() tries to call cpu_clock_event_stop() to stop the event, which calls htimer_cancel() to cancel the hrtimer. But that's a recursion into the hrtimer code from a hrtimer handler, which (unsurprisingly) deadlocks. To fix this bug, use hrtimer_try_to_cancel() instead, and set the PERF_HES_STOPPED flag, which causes perf_swevent_hrtimer() to stop the event once it sees the PERF_HES_STOPPED flag. [ mingo: Fixed the comments and improved the changelog. ]

Affected

11 ranges
VendorProductVersion rangeFixed in
debianlinux< linux 6.17.8-1 (forky)linux 6.17.8-1 (forky)
linuxlinux
linuxlinux
linuxlinux>= 18dbcbfabfffc4a5d3ea10290c5ad27f22b0d240 < 6b8c512811644cf2f5eaf6f44e928683c54127f06b8c512811644cf2f5eaf6f44e928683c54127f0
linuxlinux>= 18dbcbfabfffc4a5d3ea10290c5ad27f22b0d240 < eb3182ef0405ff2f6668fd3e5ff9883f60ce8801eb3182ef0405ff2f6668fd3e5ff9883f60ce8801
linuxlinux>= 6.16.8 < 6.176.17
linuxlinux_kernel>= 0 < 6.17.8-16.17.8-1
linuxlinux_kernel>= 0 < 6.17.0-14.146.17.0-14.14
linuxlinux_kernel>= 6.17.0 < 6.17.86.17.8
ubuntulinux-aws
ubuntulinux-oracle
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