CVE-2025-21889: linux
Vulnerability summary
CVE-2025-21889 is a high (CVSS 7.8) vulnerability in linux. EPSS estimates a 0.20% chance of exploitation in the next 30 days, higher than 9.3% of scored vulnerabilities.
Advisory lineage
Upstream 0 · Downstream 26 · Related 27Timeline
- 27-03-2025PublishedVulnerability first disclosed.
- 15-10-2026Last modifiedVulnerability information updated.
Description
In 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 metrics
4 scores · 4 sources · 1 version- OSV · UbuntuEcosystem advisory · calculated7.8HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- OSV · DebianEcosystem advisory · calculated5.5MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HDiffers
- NVDNIST5.5MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HDiffers
EPSS trend
Probability
0.20%
Chance of exploitation in the next 30 days
Percentile
9%
Versus all other CVEs
30-day change
0.00 pp
From 0.20% on 19-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeNo weakness data has been published for this record.
Affected systems
Ubuntu110 products
- linux< 6.8.0-84.84
- linux-allwinner-5.19All versions (No fix recorded)
- linux-aws< 6.8.0-1039.41
- linux-aws-5.0All versions (No fix recorded)
- linux-aws-5.11All versions (No fix recorded)
Linux2 products
- linux≥ bd27568117664b8b3e259721393df420ed51f57b, < f390c2eea571945f357a2d3b9fcb1c015767132e | ≥ bd27568117664b8b3e259721393df420ed51f57b, < a2475ccad6120546ea45dbcd6cd1f74dc565ef6b | ≥ bd27568117664b8b3e259721393df420ed51f57b, < dd536566dda9a551fc2a2acfab5313a5bb13ed02 | ≥ bd27568117664b8b3e259721393df420ed51f57b, < 0fe8813baf4b2e865d3b2c735ce1a15b86002c74 | 6.2
- linux_kernel≥ 6.2, < 6.6.81 | ≥ 6.7, < 6.12.18 | ≥ 6.13, < 6.13.6 | 6.14:rc1 | 6.14:rc2 | 6.14:rc3 | 6.14:rc4
Debian1 product
- linux< 6.12.19-1
3 vendors · 113 products