{"id":"CVE-2025-21889","url":"https://www.cyber-defence.io/tools/cve/CVE-2025-21889","generatedAt":"2026-10-28T02:19:52.177Z","title":"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.","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nperf/core: Add RCU read lock protection to perf_iterate_ctx()\n\nThe perf_iterate_ctx() function performs RCU list traversal but\ncurrently lacks RCU read lock protection. This causes lockdep warnings\nwhen running perf probe with unshare(1) under CONFIG_PROVE_RCU_LIST=y:\n\n\tWARNING: suspicious RCU usage\n\tkernel/events/core.c:8168 RCU-list traversed in non-reader section!!\n\n\t Call Trace:\n\t  lockdep_rcu_suspicious\n\t  ? perf_event_addr_filters_apply\n\t  perf_iterate_ctx\n\t  perf_event_exec\n\t  begin_new_exec\n\t  ? load_elf_phdrs\n\t  load_elf_binary\n\t  ? lock_acquire\n\t  ? find_held_lock\n\t  ? bprm_execve\n\t  bprm_execve\n\t  do_execveat_common.isra.0\n\t  __x64_sys_execve\n\t  do_syscall_64\n\t  entry_SYSCALL_64_after_hwframe\n\nThis protection was previously present but was removed in commit\nbd2756811766 (\"perf: Rewrite core context handling\"). Add back the\nnecessary rcu_read_lock()/rcu_read_unlock() pair around\nperf_iterate_ctx() call in perf_event_exec().\n\n[ mingo: Use scoped_guard() as suggested by Peter ]","published":"2025-03-27T15:15:57.000Z","lastModified":"2026-10-15T22:18:11.000Z","status":"Modified","sourceIdentifier":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","cvss":{"version":"3.1","score":5.5,"severity":"MEDIUM","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H"},"cwe":[],"affected":["linux/linux kernel"],"epss":{"score":0.00205,"percentile":0.10334,"date":"2026-10-26","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"low","text":"Lower severity and a low EPSS score (0.21%). Track it; it rarely justifies an emergency change on its own."},"changes":[],"references":[{"url":"https://git.kernel.org/stable/c/0fe8813baf4b2e865d3b2c735ce1a15b86002c74","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/a2475ccad6120546ea45dbcd6cd1f74dc565ef6b","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/dd536566dda9a551fc2a2acfab5313a5bb13ed02","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/f390c2eea571945f357a2d3b9fcb1c015767132e","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2025-21889","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}