{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2025-38352", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2025-04-16T04:51:24.006Z", "datePublished": "2025-07-22T08:04:25.277Z", "dateUpdated": "2026-08-05T12:01:20.234Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:01:20.234Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nposix-cpu-timers: fix race between handle_posix_cpu_timers() and posix_cpu_timer_del()\n\nIf an exiting non-autoreaping task has already passed exit_notify() and\ncalls handle_posix_cpu_timers() from IRQ, it can be reaped by its parent\nor debugger right after unlock_task_sighand().\n\nIf a concurrent posix_cpu_timer_del() runs at that moment, it won't be\nable to detect timer->it.cpu.firing != 0: cpu_timer_task_rcu() and/or\nlock_task_sighand() will fail.\n\nAdd the tsk->exit_state check into run_posix_cpu_timers() to fix this.\n\nThis fix is not needed if CONFIG_POSIX_CPU_TIMERS_TASK_WORK=y, because\nexit_task_work() is called before exit_notify(). But the check still\nmakes sense, task_work_add(&tsk->posix_cputimers_work.work) will fail\nanyway in this case." } ], "metrics": [ { "cvssV3_1": { "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" }, "scenarios": [ { "lang": "en", "value": "AV:L - The vulnerability is reached purely through local syscalls — `timer_create`/`timer_settime`/`timer_delete` (or `clock_nanosleep`) plus `ptrace`/`waitpid` to control task reaping — with the trigger arriving via the local timer tick. There is no network-facing path into posix-cpu-timers.\nAC:L - The attacker controls both sides of the race: it arms the CPU timer expiry, chooses the precise moment of `release_task()` by calling `waitpid()` from its own parent/tracer, and issues the concurrent `timer_delete()` from a sibling thread — retryable in a tight loop and widenable by queueing up to 20 timers on the firing list. Real-world exploitation of this exact bug confirms it is reliably winnable.\nPR:L - No capability or permission check exists anywhere on the path — `validate_clock_permissions()`/`pid_for_clock()` gate only on thread-group/pid existence, and `grep` for `capable`/`CAP_` in both posix-timers files returns nothing. Any unprivileged local user, including a seccomp-confined Android app UID, can reach it.\nUI:N - The attacker's own processes and threads perform every step — creating the timer, exiting the traced thread, reaping it, and deleting the timer. No victim action of any kind is needed.\nS:U - The use-after-free corrupts kernel heap objects and escalates within the kernel's own security authority, which is standard kernel privilege escalation. No hypervisor, IOMMU, or other security-authority boundary is crossed.\nC:H - The freed `struct sigqueue` is linked into the signal pending list by `send_sigqueue()` and later copied out to userspace through `dequeue_signal()`/`rt_sigtimedwait()`, disclosing whatever now occupies the reclaimed slab object — an effectively arbitrary kernel-memory read. The `do_cpu_nanosleep()` variant additionally exposes reclaimed kernel stack.\nI:H - `send_sigqueue()` writes into the freed object (`q->info.si_overrun++`) and performs a `list_add_tail()` linked-list insertion on attacker-resprayable memory, followed by a double free on dequeue — a classic controlled-write primitive leading to full privilege escalation, as demonstrated by in-the-wild exploitation of this flaw.\nA:H - Even without successful exploitation the race causes `BUG_ON(!(q->flags & SIGQUEUE_PREALLOC))` in `send_sigqueue()`, `WARN_ON_ONCE()` in the delete path, list corruption, and a double free — any of which oops or panic the kernel. Spinning the race is trivially repeatable as a denial of service." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "kernel/time/posix-cpu-timers.c" ], "versions": [ { "version": "0bdd2ed4138ec04e09b4f8165981efc99e439f55", "lessThan": "78a4b8e3795b31dae58762bc091bb0f4f74a2200", "status": "affected", "versionType": "git" }, { "version": "0bdd2ed4138ec04e09b4f8165981efc99e439f55", "lessThan": "c076635b3a42771ace7d276de8dc3bc76ee2ba1b", "status": "affected", "versionType": "git" }, { "version": "0bdd2ed4138ec04e09b4f8165981efc99e439f55", "lessThan": "2f3daa04a9328220de46f0d5c919a6c0073a9f0b", "status": "affected", "versionType": "git" }, { "version": "0bdd2ed4138ec04e09b4f8165981efc99e439f55", "lessThan": "764a7a5dfda23f69919441f2eac2a83e7db6e5bb", "status": "affected", "versionType": "git" }, { "version": "0bdd2ed4138ec04e09b4f8165981efc99e439f55", "lessThan": "2c72fe18cc5f9f1750f5bc148cf1c94c29e106ff", "status": "affected", "versionType": "git" }, { "version": "0bdd2ed4138ec04e09b4f8165981efc99e439f55", "lessThan": "c29d5318708e67ac13c1b6fc1007d179fb65b4d7", "status": "affected", "versionType": "git" }, { "version": "0bdd2ed4138ec04e09b4f8165981efc99e439f55", "lessThan": "460188bc042a3f40f72d34b9f7fc6ee66b0b757b", "status": "affected", "versionType": "git" }, { "version": "0bdd2ed4138ec04e09b4f8165981efc99e439f55", "lessThan": "f90fff1e152dedf52b932240ebbd670d83330eca", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "kernel/time/posix-cpu-timers.c" ], "versions": [ { "version": "2.6.36", "status": "affected" }, { "version": "0", "lessThan": "2.6.36", "status": "unaffected", "versionType": "semver" }, { "version": "5.4.295", "lessThanOrEqual": "5.4.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.239", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.186", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.142", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.94", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.34", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.15.3", "lessThanOrEqual": "6.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.16", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.36", "versionEndExcluding": "5.4.295" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.36", "versionEndExcluding": "5.10.239" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.36", "versionEndExcluding": "5.15.186" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.36", "versionEndExcluding": "6.1.142" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.36", "versionEndExcluding": "6.6.94" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.36", "versionEndExcluding": "6.12.34" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.36", "versionEndExcluding": "6.15.3" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.36", "versionEndExcluding": "6.16" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/78a4b8e3795b31dae58762bc091bb0f4f74a2200" }, { "url": "https://git.kernel.org/stable/c/c076635b3a42771ace7d276de8dc3bc76ee2ba1b" }, { "url": "https://git.kernel.org/stable/c/2f3daa04a9328220de46f0d5c919a6c0073a9f0b" }, { "url": "https://git.kernel.org/stable/c/764a7a5dfda23f69919441f2eac2a83e7db6e5bb" }, { "url": "https://git.kernel.org/stable/c/2c72fe18cc5f9f1750f5bc148cf1c94c29e106ff" }, { "url": "https://git.kernel.org/stable/c/c29d5318708e67ac13c1b6fc1007d179fb65b4d7" }, { "url": "https://git.kernel.org/stable/c/460188bc042a3f40f72d34b9f7fc6ee66b0b757b" }, { "url": "https://git.kernel.org/stable/c/f90fff1e152dedf52b932240ebbd670d83330eca" } ], "title": "posix-cpu-timers: fix race between handle_posix_cpu_timers() and posix_cpu_timer_del()", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "metrics": [ { "cvssV3_1": { "scope": "UNCHANGED", "version": "3.1", "baseScore": 7.4, "attackVector": "LOCAL", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "HIGH", "availabilityImpact": "HIGH", "privilegesRequired": "NONE", "confidentialityImpact": "HIGH" } }, { "other": { "type": "ssvc", "content": { "id": "CVE-2025-38352", "role": "CISA Coordinator", "options": [ { "Exploitation": "active" }, { "Automatable": "no" }, { "Technical Impact": "total" } ], "version": "2.0.3", "timestamp": "2025-09-05T03:55:31.566379Z" } } }, { "other": { "type": "kev", "content": { "dateAdded": "2025-09-04", "reference": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-38352" } } } ], "references": [ { "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-38352", "tags": [ "government-resource" ] }, { "url": "https://github.com/farazsth98/chronomaly", "tags": [ "exploit" ] } ], "problemTypes": [ { "descriptions": [ { "lang": "en", "type": "CWE", "cweId": "CWE-367", "description": "CWE-367 Time-of-check Time-of-use (TOCTOU) Race Condition" } ] } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-02-26T17:50:25.787Z" } }, { "title": "CVE Program Container", "references": [ { "url": "https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html" }, { "url": "https://lists.debian.org/debian-lts-announce/2025/10/msg00007.html" } ], "providerMetadata": { "orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2025-11-03T17:37:02.965Z" } } ] } }