perf/core: Fix system hang caused by cpu-clock usage
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. ]
CVE 정보
EPSS
EPSS는 취약점이 악용될 가능성을 예측하는 점수 모델입니다.
EPSS 점수
EPSS 모델은 0과 1(0~100%) 사이의 확률 점수를 생성합니다. 점수가 높을수록 취약점이 악용될 가능성이 높습니다.
날짜
EPSS V0
EPSS V1
EPSS V2 (> 2022-02-04)
EPSS V3 (> 2025-03-07)
EPSS V4 (> 2025-03-17)
2025-12-09
–
–
–
–
0.02%
2025-12-15
–
–
–
–
0.02%
2026-01-10
–
–
–
–
0.03%
2026-02-22
–
–
–
–
0.03%
2026-03-01
–
–
–
–
0.03%
2026-03-08
–
–
–
–
0.03%
2026-03-22
–
–
–
–
0.03%
2026-04-12
–
–
–
–
0.04%
2026-04-26
–
–
–
–
0.04%
2026-05-10
–
–
–
–
0.02%
2026-05-31
–
–
–
–
0.03%
EPSS 백분위수
백분위수는 EPSS 점수에 따라 CVE의 순위를 매기는 데 사용됩니다. 예를 들어 EPSS 점수 기준 95번째 백분위수의 CVE는 다른 CVE의 95%보다 악용될 가능성이 높습니다.