{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-99218", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-25T10:25:14.401Z", "datePublished": "2026-11-02T16:06:31.088Z", "dateUpdated": "2026-11-03T19:12:53.426Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-11-03T19:12:53.426Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ncoredump: hold RCU while releasing parked threads\n\ncoredump_finish() releases the parked threads by clearing ->task in\ntheir core_thread entry and calling wake_up_process() on each of them.\nIt does that without holding a reference on the task and without being\ninside rcu.\n\nBut calling wake_up_process(task) without rcu here isn't safe. A parked\nthread doesn't need that wakeup to leave. A spurious wakeup or a\npreemption after the store is enough for the task to go away.\n\nSo if the coredump client is preempted between the store and\nwake_up_process() the thread can exit and be freed in the meantime and\ntry_to_wake_up() takes pi_lock in freed memory.\n\nHold rcu across the loop." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - The UAF is in coredump_finish(), reached when a local dump signal is delivered via get_signal() -> vfs_coredump() -> do_coredump()/coredump_cleanup(). abort(), a user page-fault SIGSEGV, or tgkill() on the attacker's own thread group starts that path; no remote protocol supplies the curr->task pointer later handed to wake_up_process().\nAC:H - coredump_wait() parks siblings in coredump_task_exit() in TASK_IDLE (no TASK_WAKEKILL), so kill/tgkill cannot wake them. The UAF needs the dumper preempted between curr->task=NULL and wake_up_process() long enough for a spurious or freezer wakeup, full do_exit(), and an RCU GP via delayed_put_task_struct() — timing the attacker cannot force.\nPR:L - get_signal() dumps the caller's own dumpable thread group with no capability check. An ordinary user pthread_create()s a sibling and abort()s or faults into vfs_coredump(); coredump_skip() only bails on TASK_DUMPABLE_OFF, which a normal user process is not.\nUI:N - The attacker creates the extra thread and delivers the dump signal inside their own process; no other user must mount media, open a file, or otherwise act.\nS:U - try_to_wake_up() on the freed task_struct corrupts host kernel scheduler state inside the same kernel; this is ordinary in-kernel UAF impact, not a VM, IOMMU, or sandbox escape.\nC:H - wake_up_process() -> try_to_wake_up() reads __state, on_rq, and sched_class from the task_struct after delayed_put_task_struct() has freed it; a sprayable slab UAF read is High confidentiality per UAF guidance.\nI:H - try_to_wake_up() takes raw_spin_lock on the freed p->pi_lock, writes __state, and calls p->sched_class->enqueue_task(); reclaiming the task_struct slab yields a write and control-flow primitive.\nA:H - Taking pi_lock in memory already freed by delayed_put_task_struct(), as the fix describes, oopses or panics even without a successful spray, so availability is High." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/coredump.c" ], "versions": [ { "version": "a94e2d408eaedbd85aae259621d46fafc10479a2", "lessThan": "fd0fbe84312fda2fc187428c92c50b7d03a9d24c", "status": "affected", "versionType": "git" }, { "version": "a94e2d408eaedbd85aae259621d46fafc10479a2", "lessThan": "71146c437bae59e5280f657965dc6d006ee3989b", "status": "affected", "versionType": "git" }, { "version": "a94e2d408eaedbd85aae259621d46fafc10479a2", "lessThan": "0fce73efee40c65ce26641c5d93942462f9e8307", "status": "affected", "versionType": "git" }, { "version": "a94e2d408eaedbd85aae259621d46fafc10479a2", "lessThan": "16e94ed90b1b02398e044d41fd1db34828daa08e", "status": "affected", "versionType": "git" }, { "version": "a94e2d408eaedbd85aae259621d46fafc10479a2", "lessThan": "a0f09ff4c6b93312e565cfe75d76c3a551a3ec4c", "status": "affected", "versionType": "git" }, { "version": "a94e2d408eaedbd85aae259621d46fafc10479a2", "lessThan": "b0eca0edddf4c1dbaf6d1f6a8636b4235f5bc573", "status": "affected", "versionType": "git" }, { "version": "a94e2d408eaedbd85aae259621d46fafc10479a2", "lessThan": "61d58591aa0188bf2463e263962256316ff8b576", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/coredump.c" ], "versions": [ { "version": "2.6.27", "status": "affected" }, { "version": "0", "lessThan": "2.6.27", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.191", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.161", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.115", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.60", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2.14", "lessThanOrEqual": "7.2.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.3.1", "lessThanOrEqual": "7.3.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.4-rc1", "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": "2.6.27", "versionEndExcluding": "6.1.191" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.27", "versionEndExcluding": "6.6.161" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.27", "versionEndExcluding": "6.12.115" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.27", "versionEndExcluding": "6.18.60" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.27", "versionEndExcluding": "7.2.14" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.27", "versionEndExcluding": "7.3.1" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.27", "versionEndExcluding": "7.4-rc1" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/fd0fbe84312fda2fc187428c92c50b7d03a9d24c" }, { "url": "https://git.kernel.org/stable/c/71146c437bae59e5280f657965dc6d006ee3989b" }, { "url": "https://git.kernel.org/stable/c/0fce73efee40c65ce26641c5d93942462f9e8307" }, { "url": "https://git.kernel.org/stable/c/16e94ed90b1b02398e044d41fd1db34828daa08e" }, { "url": "https://git.kernel.org/stable/c/a0f09ff4c6b93312e565cfe75d76c3a551a3ec4c" }, { "url": "https://git.kernel.org/stable/c/b0eca0edddf4c1dbaf6d1f6a8636b4235f5bc573" }, { "url": "https://git.kernel.org/stable/c/61d58591aa0188bf2463e263962256316ff8b576" } ], "title": "coredump: hold RCU while releasing parked threads", "x_generator": { "engine": "bippy-1.2.0" } } } }