{"id":"CVE-2026-53085","summary":"bpf: fix mm lifecycle in open-coded task_vma iterator","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: fix mm lifecycle in open-coded task_vma iterator\n\nThe open-coded task_vma iterator reads task-\u003emm locklessly and acquires\nmmap_read_trylock() but never calls mmget(). If the task exits\nconcurrently, the mm_struct can be freed as it is not\nSLAB_TYPESAFE_BY_RCU, resulting in a use-after-free.\n\nSafely read task-\u003emm with a trylock on alloc_lock and acquire an mm\nreference. Drop the reference via bpf_iter_mmput_async() in _destroy()\nand error paths. bpf_iter_mmput_async() is a local wrapper around\nmmput_async() with a fallback to mmput() on !CONFIG_MMU.\n\nReject irqs-disabled contexts (including NMI) up front. Operations used\nby _next() and _destroy() (mmap_read_unlock, bpf_iter_mmput_async)\ntake spinlocks with IRQs disabled (pool-\u003elock, pi_lock). Running from\nNMI or from a tracepoint that fires with those locks held could\ndeadlock.\n\nA trylock on alloc_lock is used instead of the blocking task_lock()\n(get_task_mm) to avoid a deadlock when a softirq BPF program iterates\na task that already holds its alloc_lock on the same CPU.","modified":"2026-07-08T08:07:23.723027557Z","published":"2026-06-24T16:30:25.232Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/53xxx/CVE-2026-53085.json","cna_assigner":"Linux"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/239cec25a22662dbd80f57d94b38178c8be95269"},{"type":"WEB","url":"https://git.kernel.org/stable/c/43683bb280330f3d36f0f2a3932a4867b9603e9c"},{"type":"WEB","url":"https://git.kernel.org/stable/c/d0862de7c866c5bd7c32531f66738c21197af888"},{"type":"WEB","url":"https://git.kernel.org/stable/c/d8e27d2d22b6e2df3a0125b8c08e9aace38c954c"},{"type":"WEB","url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-53085.json"},{"type":"ADVISORY","url":"https://access.redhat.com/security/cve/CVE-2026-53085"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/53xxx/CVE-2026-53085.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-53085"},{"type":"REPORT","url":"https://bugzilla.redhat.com/show_bug.cgi?id=2492404"},{"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":"4ac4546821584736798aaa9e97da9f6eaf689ea3"},{"fixed":"239cec25a22662dbd80f57d94b38178c8be95269"},{"fixed":"d0862de7c866c5bd7c32531f66738c21197af888"},{"fixed":"43683bb280330f3d36f0f2a3932a4867b9603e9c"},{"fixed":"d8e27d2d22b6e2df3a0125b8c08e9aace38c954c"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-53085.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.91"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.33"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.0.10"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-53085.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"}]}