{"id":"CVE-2026-93137","summary":"bpf: Fix use-after-free on mm_struct in bpf_find_vma()","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Fix use-after-free on mm_struct in bpf_find_vma()\n\nbpf_find_vma() reads task-\u003emm and calls mmap_read_trylock(mm) without\nholding a reference on the mm. On a foreign task, a concurrent exit_mm()\ncan free the mm_struct between the lockless read and the trylock,\nresulting in a use-after-free. mm_struct is not SLAB_TYPESAFE_BY_RCU.\n\nFor the current task, task-\u003emm is stable. For a foreign task, pin the mm\nunder task-\u003ealloc_lock and release it with mmput_async(), mirroring commit\nd8e27d2d22b6 (\"bpf: fix mm lifecycle in open-coded task_vma iterator\").\nUse spin_trylock() instead of get_task_mm() so BPF context does not block\non alloc_lock. Reject irqs-disabled contexts and !CONFIG_MMU on the\nforeign-task path because dropping the mm reference is not safe there.\n\nRace:\n\n  CPU0 (BPF program)                  CPU1 (exiting task)\n  ============================        ==========================\n  bpf_find_vma(foreign_task):\n    mm = task-\u003emm\n                                      exit_mm():\n                                        task-\u003emm = NULL\n                                        mmput(mm) -\u003e frees mm_struct\n    mmap_read_trylock(mm)\n        // UAF on mm","modified":"2026-09-19T03:47:27.886402526Z","published":"2026-09-17T16:11:38.135Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/93xxx/CVE-2026-93137.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/2b2a903bee56d312539046d9defa8023eec94760"},{"type":"WEB","url":"https://git.kernel.org/stable/c/47b079e2117a2ee52e21f8b72935900c702fc0b5"},{"type":"WEB","url":"https://git.kernel.org/stable/c/86d54cf069fc5ae2e111c87933bebf6eb527978e"},{"type":"WEB","url":"https://git.kernel.org/stable/c/8e1101fc4118019a69c96ced4aec93164f89cbd5"},{"type":"WEB","url":"https://git.kernel.org/stable/c/c7ad910e987008e125eeff448892e86852173384"},{"type":"WEB","url":"https://git.kernel.org/stable/c/db347840d6b6ee9bb9b8e4a985d4b4419f9f3200"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/93xxx/CVE-2026-93137.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-93137"},{"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":"7c7e3d31e7856a8260a254f8c71db416f7f9f5a1"},{"fixed":"db347840d6b6ee9bb9b8e4a985d4b4419f9f3200"},{"fixed":"8e1101fc4118019a69c96ced4aec93164f89cbd5"},{"fixed":"c7ad910e987008e125eeff448892e86852173384"},{"fixed":"86d54cf069fc5ae2e111c87933bebf6eb527978e"},{"fixed":"2b2a903bee56d312539046d9defa8023eec94760"},{"fixed":"47b079e2117a2ee52e21f8b72935900c702fc0b5"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-93137.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"5.17.0"},{"fixed":"6.1.188"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.6.157"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.110"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.52"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.2.6"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-93137.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"}]}