{"id":"CVE-2026-46173","summary":"exit: prevent preemption of oopsing TASK_DEAD task","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nexit: prevent preemption of oopsing TASK_DEAD task\n\nWhen an already-exiting task oopses, make_task_dead() currently calls\ndo_task_dead() with preemption enabled.  That is forbidden:\ndo_task_dead() calls __schedule(), which has a comment saying \"WARNING:\nmust be called with preemption disabled!\".\n\nIf an oopsing task is preempted in do_task_dead(), between becoming\nTASK_DEAD and entering the scheduler explicitly, bad things happen:\nfinish_task_switch() assumes that once the scheduler has switched away\nfrom a TASK_DEAD task, the task can never run again and its stack is no\nlonger needed; but that assumption apparently doesn't hold if the dead\ntask was preempted (the SM_PREEMPT case).\n\nThis means that the scheduler ends up repeatedly dropping references on\nthe dead task's stack, which can lead to use-after-free or double-free\nof the entire task stack; in other words, two tasks can end up running\non the same stack, resulting in various kinds of memory corruption.\n\n(This does not just affect \"recursively oopsing\" tasks; it is enough to\noops once during task exit, for example in a file_operations::release\nhandler)","modified":"2026-06-23T15:29:20.184168539Z","published":"2026-05-28T09:36:27.892Z","related":["ALSA-2026:27789","openSUSE-SU-2026:10954-1"],"database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/46xxx/CVE-2026-46173.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/3d6fb8a7690c23e3213c4b008f64d89a44b98737"},{"type":"WEB","url":"https://git.kernel.org/stable/c/640b4c00fb0e2920327435f6176cbefc3c546165"},{"type":"WEB","url":"https://git.kernel.org/stable/c/6f49f94f3b11fe8bff1bf2a054143789e76aaf17"},{"type":"WEB","url":"https://git.kernel.org/stable/c/7b2800ba5f5f77a8ee7f4cbadb19cf1264597a34"},{"type":"WEB","url":"https://git.kernel.org/stable/c/9756b3db5db6c2f5eccb32dddbd88eb4c54f575e"},{"type":"WEB","url":"https://git.kernel.org/stable/c/c1fa0bb633e4a6b11e83ffc57fa5abe8ebb87891"},{"type":"WEB","url":"https://project-zero.issues.chromium.org/issues/510793286"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/46xxx/CVE-2026-46173.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-46173"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"7f80a2fd7db9a55894fd841915236aca611291b5"},{"fixed":"3d6fb8a7690c23e3213c4b008f64d89a44b98737"},{"fixed":"640b4c00fb0e2920327435f6176cbefc3c546165"},{"fixed":"7b2800ba5f5f77a8ee7f4cbadb19cf1264597a34"},{"fixed":"6f49f94f3b11fe8bff1bf2a054143789e76aaf17"},{"fixed":"9756b3db5db6c2f5eccb32dddbd88eb4c54f575e"},{"fixed":"c1fa0bb633e4a6b11e83ffc57fa5abe8ebb87891"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-46173.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"5.17.0"},{"fixed":"6.1.175"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.6.140"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.88"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.30"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.0.7"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-46173.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"}]}