CVE-2025-21889
MediumIn the Linux kernel, the following vulnerability has been resolved: perf/core: Add RCU read lock protection to perf_iterate_ctx() The perf_iterate_ctx() function performs RCU list traversal but currently lacks RCU read lock protection. This causes lockdep warnings when running perf probe with unshare(1) under CONFIG_PROVE_RCU_LIST=y: WARNING: suspicious RCU usage kernel/events/core.c:8168 RCU-list traversed in non-reader section!! Call Trace: lockdep_rcu_suspicious ? perf_event_addr_filters_apply perf_iterate_ctx perf_event_exec begin_new_exec ? load_elf_phdrs load_elf_binary ? lock_acquire ? find_held_lock ? bprm_execve bprm_execve do_execveat_common.isra.0 __x64_sys_execve do_syscall_64 entry_SYSCALL_64_after_hwframe This protection was previously present but was removed in commit bd2756811766 ("perf: Rewrite core context handling"). Add back the necessary rcu_read_lock()/rcu_read_unlock() pair around perf_iterate_ctx() call in perf_event_exec(). [ mingo: Use scoped_guard() as suggested by Peter ]
CVSS 3.1 score
5.5
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Affected versions
Linux kernel versions
6.2
and later are affected. Fixed in
6.6.81,
6.12.18,
6.13.6,
6.14
and their respective stable series.
References
The following references provide additional information about CVE-2025-21889 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.
-
PatchKernel patch commithttps://git.kernel.org/stable/c/0fe8813baf4b2e865d3b2c735ce1a15b86002c74
-
PatchKernel patch commithttps://git.kernel.org/stable/c/a2475ccad6120546ea45dbcd6cd1f74dc565ef6b
-
PatchKernel patch commithttps://git.kernel.org/stable/c/dd536566dda9a551fc2a2acfab5313a5bb13ed02
Frequently asked questions
-
What is CVE-2025-21889?
CVE-2025-21889 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10 . It affects Linux kernel versions from 6.2 onward and has been patched in 6.6.81, 6.12.18, 6.13.6 and others. CVE-2025-21889 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
-
What is the CVSS score for CVE-2025-21889?
CVE-2025-21889 has a CVSS score of 5.5 out of 10, rated Medium severity (CVSS 3.1). The vector string is
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H. -
Is there a patch available for CVE-2025-21889?
Yes — CVE-2025-21889 has been patched. Fixed versions include 6.6.81, 6.12.18, 6.13.6 and others. If you are running Linux kernel 6.2 or later up to the fix versions, apply the relevant patch for your kernel branch.
-
Is CVE-2025-21889 actively exploited?
No — CVE-2025-21889 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.