{"api_version":"1","generated_at":"2026-10-28T03:42:08+00:00","cve":"CVE-2025-21889","urls":{"html":"https://cve.report/CVE-2025-21889","api":"https://cve.report/api/cve/CVE-2025-21889.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2025-21889","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2025-21889"},"summary":{"title":"perf/core: Add RCU read lock protection to perf_iterate_ctx()","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 ]","state":"PUBLISHED","assigner":"Linux","published_at":"2025-03-27 15:15:56","updated_at":"2026-10-15 22:18:11"},"problem_types":["NVD-CWE-noinfo"],"metrics":[{"version":"3.1","source":"nvd@nist.gov","type":"Primary","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","data":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","baseScore":5.5,"baseSeverity":"MEDIUM","attackVector":"LOCAL","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"NONE","availabilityImpact":"HIGH"}},{"version":"3.1","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","type":"Secondary","score":"7.8","severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","data":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH","attackVector":"LOCAL","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH"}},{"version":"3.1","source":"CNA","type":"DECLARED","score":"7.8","severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","data":{"baseScore":7.8,"baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","version":"3.1"}}],"references":[{"url":"https://git.kernel.org/stable/c/f390c2eea571945f357a2d3b9fcb1c015767132e","name":"https://git.kernel.org/stable/c/f390c2eea571945f357a2d3b9fcb1c015767132e","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":["Patch"],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/a2475ccad6120546ea45dbcd6cd1f74dc565ef6b","name":"https://git.kernel.org/stable/c/a2475ccad6120546ea45dbcd6cd1f74dc565ef6b","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":["Patch"],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/0fe8813baf4b2e865d3b2c735ce1a15b86002c74","name":"https://git.kernel.org/stable/c/0fe8813baf4b2e865d3b2c735ce1a15b86002c74","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":["Patch"],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/dd536566dda9a551fc2a2acfab5313a5bb13ed02","name":"https://git.kernel.org/stable/c/dd536566dda9a551fc2a2acfab5313a5bb13ed02","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":["Patch"],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2025-21889","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2025-21889","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected bd27568117664b8b3e259721393df420ed51f57b f390c2eea571945f357a2d3b9fcb1c015767132e git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected bd27568117664b8b3e259721393df420ed51f57b a2475ccad6120546ea45dbcd6cd1f74dc565ef6b git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected bd27568117664b8b3e259721393df420ed51f57b dd536566dda9a551fc2a2acfab5313a5bb13ed02 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected bd27568117664b8b3e259721393df420ed51f57b 0fe8813baf4b2e865d3b2c735ce1a15b86002c74 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 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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 ]"}],"metrics":[{"cvssV3_1":{"baseScore":7.8,"baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","version":"3.1"},"scenarios":[{"lang":"en","value":"AV:L - The vulnerable path is entered through local syscalls only — `execve()` reaching `perf_event_exec()` via `begin_new_exec()`, with the racing side driven by `perf_event_open()`/`close()`. No network or remote input reaches this code.\nAC:L - The attacker controls both sides of the race, looping `execve()` in one process while closing perf event fds attached to it from another, and can widen the window arbitrarily via CPU pinning and the cross-CPU IPI that `perf_event_stop()` issues inside the unprotected walk. Nothing about the trigger depends on conditions outside the attacker's influence.\nPR:L - An ordinary unprivileged user suffices: `sysctl_perf_event_paranoid` defaults to 2, which permits task-bound user-space perf events on same-uid processes, and no capability is checked anywhere on the `execve()` side of the race.\nUI:N - Both the exec'ing process and the event-closing process are attacker-controlled; no victim action or cooperation is needed.\nS:U - The corruption stays within the kernel's own security authority — a standard local kernel memory-safety flaw with no crossing of a VM, IOMMU, or sandbox boundary.\nC:H - The unprotected RCU walk dereferences a freed `struct perf_event`, and the reclaimed slot can be groomed with attacker-sprayed perf events, giving a use-after-free read primitive that leaks kernel memory and pointers.\nI:H - `perf_event_addr_filters_exec()` writes into the freed object — zeroing `addr_filter_ranges[count].start/.size` through a pointer read out of reclaimed memory and incrementing `addr_filters_gen` — yielding an attacker-influenced kernel write suitable for privilege escalation.\nA:H - Traversing a freed list entry corrupts the walk and readily produces list corruption, an oops, or a full kernel panic, and the race can be retriggered in a loop."}]}],"providerMetadata":{"dateUpdated":"2026-08-05T11:55:10.093Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/f390c2eea571945f357a2d3b9fcb1c015767132e"},{"url":"https://git.kernel.org/stable/c/a2475ccad6120546ea45dbcd6cd1f74dc565ef6b"},{"url":"https://git.kernel.org/stable/c/dd536566dda9a551fc2a2acfab5313a5bb13ed02"},{"url":"https://git.kernel.org/stable/c/0fe8813baf4b2e865d3b2c735ce1a15b86002c74"}],"title":"perf/core: Add RCU read lock protection to perf_iterate_ctx()","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2025-21889","datePublished":"2025-03-27T14:57:15.897Z","dateReserved":"2024-12-29T08:45:45.782Z","dateUpdated":"2026-10-15T21:51:54.984Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2025-03-27 15:15:56","lastModifiedDate":"2026-10-15 22:18:11","problem_types":["NVD-CWE-noinfo"],"metrics":{"cvssMetricV31":[{"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH","attackVector":"LOCAL","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH"},"exploitabilityScore":1.8,"impactScore":5.9},{"source":"nvd@nist.gov","type":"Primary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","baseScore":5.5,"baseSeverity":"MEDIUM","attackVector":"LOCAL","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"NONE","availabilityImpact":"HIGH"},"exploitabilityScore":1.8,"impactScore":3.6}],"ssvcV203":[{"source":"134c704f-9b21-4f2e-91b3-4a467353bcc0","ssvcData":{"timestamp":"2026-10-15T21:43:34.538197Z","id":"CVE-2025-21889","options":[{"exploitation":"none"},{"automatable":"no"},{"technicalImpact":"total"}],"role":"CISA Coordinator","version":"2.0.3"}}]},"configurations":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.2","versionEndExcluding":"6.6.81","matchCriteriaId":"8C92C9CD-2ADE-412E-A7FF-DC9E0630B25D"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.7","versionEndExcluding":"6.12.18","matchCriteriaId":"3D5C8D9A-4013-4C1A-810F-AA540BB5737C"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.13","versionEndExcluding":"6.13.6","matchCriteriaId":"64F12D9B-71C2-4CD7-A288-0D5EF1709620"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:6.14:rc1:*:*:*:*:*:*","matchCriteriaId":"186716B6-2B66-4BD0-852E-D48E71C0C85F"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:6.14:rc2:*:*:*:*:*:*","matchCriteriaId":"0D3E781C-403A-498F-9DA9-ECEE50F41E75"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:6.14:rc3:*:*:*:*:*:*","matchCriteriaId":"66619FB8-0AAF-4166-B2CF-67B24143261D"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:6.14:rc4:*:*:*:*:*:*","matchCriteriaId":"D3D6550E-6679-4560-902D-AF52DCFE905B"}]}]}]},"legacy_mitre":{"record":{"CveYear":"2025","CveId":"21889","Ordinal":"1","Title":"perf/core: Add RCU read lock protection to perf_iterate_ctx()","CVE":"CVE-2025-21889","Year":"2025"},"notes":[{"CveYear":"2025","CveId":"21889","Ordinal":"1","NoteData":"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 ]","Type":"Description","Title":"perf/core: Add RCU read lock protection to perf_iterate_ctx()"}]}}}