{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-93137", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-17T16:02:15.088Z", "datePublished": "2026-09-17T16:11:38.135Z", "dateUpdated": "2026-10-19T09:06:10.069Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-19T09:06:10.069Z" }, "descriptions": [ { "lang": "en", "value": "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->mm 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->mm is stable. For a foreign task, pin the mm\nunder task->alloc_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->mm\n exit_mm():\n task->mm = NULL\n mmput(mm) -> frees mm_struct\n mmap_read_trylock(mm)\n // UAF on mm" } ], "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 - bpf_find_vma() is invoked only from a program loaded via bpf(BPF_PROG_LOAD): BPF_PROG_TYPE_SYSCALL (syscall_prog_func_proto) or tracing/raw_tp (bpf_tracing_func_proto), both reaching bpf_base_func_proto() for BPF_FUNC_find_vma. The stale mm comes from bpf_task_from_pid() or a tracing task argument, not from a remote protocol field.\nAC:L - The race is inside bpf_find_vma() between the lockless task->mm load and mmap_read_trylock(mm). The attacker forks a child, looks it up with bpf_task_from_pid(), and hammers BPF_PROG_RUN (or an attached raw_tp) while that child exits so exit_mm()→mmput() frees the mm; they control both sides.\nPR:L - bpf_base_func_proto() returns bpf_find_vma_proto only after bpf_token_capable(CAP_PERFMON); bpf_prog_load() also needs CAP_BPF, and RAW_TRACEPOINT/TRACING fail is_perfmon_prog_type() without CAP_PERFMON. bpf_token_capable() uses ns_capable() on a delegated token's userns, so this is not init-namespace root.\nUI:N - The attacker loads the program with BPF_PROG_LOAD, runs it via BPF_PROG_RUN or their own attached probe, and exits their own child so exit_mm() races bpf_find_vma(); no other user must mount a filesystem or open a file.\nS:U - mmap_read_trylock() and find_vma() operate on the host kernel mm_struct that bpf_find_vma() cached from task->mm. That is in-kernel memory corruption in the same authority as the bpf() caller, not a KVM/Xen guest-to-host or IOMMU escape.\nC:H - After exit_mm() mmput() frees the mm_struct (mm_cachep is not SLAB_TYPESAFE_BY_RCU), bpf_find_vma() still calls find_vma(mm, start) and hands the resulting vm_area_struct to the BPF callback, so the program can read reallocated kernel VMA/mm memory.\nI:H - The stale mm is used by mmap_read_trylock() (down_read_trylock on mm->mmap_lock) and bpf_mmap_unlock_mm(); those write a freed mm_struct, and find_vma() may walk a reallocated maple tree, which is UAF corruption exploitable for an arbitrary kernel write.\nA:H - down_read_trylock on a freed mm->mmap_lock or find_vma() walking a freed mm->mm_mt oopses or panics the kernel, and the attacker can repeat bpf_find_vma() against children they exit." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "kernel/bpf/task_iter.c" ], "versions": [ { "version": "7c7e3d31e7856a8260a254f8c71db416f7f9f5a1", "lessThan": "db347840d6b6ee9bb9b8e4a985d4b4419f9f3200", "status": "affected", "versionType": "git" }, { "version": "7c7e3d31e7856a8260a254f8c71db416f7f9f5a1", "lessThan": "8e1101fc4118019a69c96ced4aec93164f89cbd5", "status": "affected", "versionType": "git" }, { "version": "7c7e3d31e7856a8260a254f8c71db416f7f9f5a1", "lessThan": "c7ad910e987008e125eeff448892e86852173384", "status": "affected", "versionType": "git" }, { "version": "7c7e3d31e7856a8260a254f8c71db416f7f9f5a1", "lessThan": "86d54cf069fc5ae2e111c87933bebf6eb527978e", "status": "affected", "versionType": "git" }, { "version": "7c7e3d31e7856a8260a254f8c71db416f7f9f5a1", "lessThan": "2b2a903bee56d312539046d9defa8023eec94760", "status": "affected", "versionType": "git" }, { "version": "7c7e3d31e7856a8260a254f8c71db416f7f9f5a1", "lessThan": "47b079e2117a2ee52e21f8b72935900c702fc0b5", "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/bpf/task_iter.c" ], "versions": [ { "version": "5.17", "status": "affected" }, { "version": "0", "lessThan": "5.17", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.188", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.157", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.110", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.52", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2.6", "lessThanOrEqual": "7.2.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.3", "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": "5.17", "versionEndExcluding": "6.1.188" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.17", "versionEndExcluding": "6.6.157" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.17", "versionEndExcluding": "6.12.110" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.17", "versionEndExcluding": "6.18.52" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.17", "versionEndExcluding": "7.2.6" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.17", "versionEndExcluding": "7.3" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/db347840d6b6ee9bb9b8e4a985d4b4419f9f3200" }, { "url": "https://git.kernel.org/stable/c/8e1101fc4118019a69c96ced4aec93164f89cbd5" }, { "url": "https://git.kernel.org/stable/c/c7ad910e987008e125eeff448892e86852173384" }, { "url": "https://git.kernel.org/stable/c/86d54cf069fc5ae2e111c87933bebf6eb527978e" }, { "url": "https://git.kernel.org/stable/c/2b2a903bee56d312539046d9defa8023eec94760" }, { "url": "https://git.kernel.org/stable/c/47b079e2117a2ee52e21f8b72935900c702fc0b5" } ], "title": "bpf: Fix use-after-free on mm_struct in bpf_find_vma()", "x_generator": { "engine": "bippy-1.2.0" } } } }