Race Condition Affecting perf package, versions *


Severity

Recommended
0.0
medium
0
10

Based on CentOS security rating.

Threat Intelligence

EPSS
0.02% (6th percentile)

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  • Snyk IDSNYK-CENTOS6-PERF-13266705
  • published4 Oct 2025
  • disclosed1 Oct 2025

Introduced: 1 Oct 2025

CVE-2025-39900  (opens in a new tab)
CWE-362  (opens in a new tab)

How to fix?

There is no fixed version for Centos:6 perf.

NVD Description

Note: Versions mentioned in the description apply only to the upstream perf package and not the perf package as distributed by Centos. See How to fix? for Centos:6 relevant fixed versions and status.

In the Linux kernel, the following vulnerability has been resolved:

net_sched: gen_estimator: fix est_timer() vs CONFIG_PREEMPT_RT=y

syzbot reported a WARNING in est_timer() [1]

Problem here is that with CONFIG_PREEMPT_RT=y, timer callbacks can be preempted.

Adopt preempt_disable_nested()/preempt_enable_nested() to fix this.

[1] WARNING: CPU: 0 PID: 16 at ./include/linux/seqlock.h:221 _seqprop_assert include/linux/seqlock.h:221 [inline] WARNING: CPU: 0 PID: 16 at ./include/linux/seqlock.h:221 est_timer+0x6dc/0x9f0 net/core/gen_estimator.c:93 Modules linked in: CPU: 0 UID: 0 PID: 16 Comm: ktimers/0 Not tainted syzkaller #0 PREEMPT{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:__seqprop_assert include/linux/seqlock.h:221 [inline] RIP: 0010:est_timer+0x6dc/0x9f0 net/core/gen_estimator.c:93 Call Trace: <TASK> call_timer_fn+0x17e/0x5f0 kernel/time/timer.c:1747 expire_timers kernel/time/timer.c:1798 [inline] __run_timers kernel/time/timer.c:2372 [inline] __run_timer_base+0x648/0x970 kernel/time/timer.c:2384 run_timer_base kernel/time/timer.c:2393 [inline] run_timer_softirq+0xb7/0x180 kernel/time/timer.c:2403 handle_softirqs+0x22c/0x710 kernel/softirq.c:579 __do_softirq kernel/softirq.c:613 [inline] run_ktimerd+0xcf/0x190 kernel/softirq.c:1043 smpboot_thread_fn+0x53f/0xa60 kernel/smpboot.c:160 kthread+0x70e/0x8a0 kernel/kthread.c:463 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 </TASK>

CVSS Base Scores

version 3.1