{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2024-42075","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2024-07-29T15:50:41.169Z","datePublished":"2024-07-29T15:52:38.154Z","dateUpdated":"2026-08-05T11:35:31.428Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-08-05T11:35:31.428Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Fix remap of arena.\n\nThe bpf arena logic didn't account for mremap operation. Add a refcnt for\nmultiple mmap events to prevent use-after-free in arena_vm_close."}],"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 - The vulnerability is reached through the bpf(2) syscall (map creation or BPF_OBJ_GET on a bpffs pin) followed by mmap()/mremap()/fork() on the arena map fd, all of which require local access to the system. There is no network-facing path into kernel/bpf/arena.c.\nAC:L - Triggering is fully deterministic with no race involved — mmap the arena, then either fork() and let both processes exit, or mremap() the VMA to a new address and unmap it, and arena_vm_close() runs twice on the same vma_list object. No unusual kernel config is needed since arena.c is built with CONFIG_BPF_SYSCALL.\nPR:L - The trigger (mmap/mremap/fork on an arena map fd) needs no privileges at all, and an fd can be obtained by an unprivileged process via a bpffs pin, since bpf_obj_do_get() gates only on path_permission() and bpf_map_mmap() performs no capability check. Arena map creation itself is reachable by an unprivileged user in a user namespace through a delegated BPF token (bpf_token_capable() uses ns_capable() against token->userns), which is the intended container delegation model shipped in the same release.\nUI:N - The attacking process performs every step itself — create/obtain the map fd, mmap, then fork or mremap and exit. No action by any other user or victim process is required.\nS:U - The corruption is confined to kernel slab memory and the BPF arena's own bookkeeping, all within the kernel's security authority. No VM, IOMMU, or sandbox boundary is crossed.\nC:H - The dangling vma_list pointer is dereferenced after being freed from the kmalloc-32 cache, so an attacker who reclaims the object with a heap spray gets the kernel reading and acting on attacker-shaped data, and the unlink write can be aimed to disclose arbitrary kernel memory. The corrupted arena->vma_list also breaks the liveness check in arena_map_free(), extending the exposure to arena-backed pages.\nI:H - The second arena_vm_close() performs list_del() on freed, attacker-reclaimable memory, giving the classic unlink write-what-where primitive with both the prev and next pointers under attacker control, and then kfree()s the object a second time. Combined, this yields arbitrary kernel memory write and a controlled double free, i.e. a realistic path to privilege escalation.\nA:H - Even without any exploitation attempt, the double free and use-after-free reliably produce slab corruption, list poison dereferences, and kernel panics (immediately so with KASAN, CONFIG_DEBUG_LIST, or CONFIG_LIST_HARDENED). An unprivileged local user can repeat this at will to crash the machine."}]}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["kernel/bpf/arena.c"],"versions":[{"version":"317460317a02a1af512697e6e964298dedd8a163","lessThan":"87496a1b01e8e2e399428c0db25e106f7961d01e","status":"affected","versionType":"git"},{"version":"317460317a02a1af512697e6e964298dedd8a163","lessThan":"b90d77e5fd784ada62ddd714d15ee2400c28e1cf","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/arena.c"],"versions":[{"version":"6.9","status":"affected"},{"version":"0","lessThan":"6.9","status":"unaffected","versionType":"semver"},{"version":"6.9.8","lessThanOrEqual":"6.9.*","status":"unaffected","versionType":"semver"},{"version":"6.10","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":"6.9","versionEndExcluding":"6.9.8"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.9","versionEndExcluding":"6.10"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/87496a1b01e8e2e399428c0db25e106f7961d01e"},{"url":"https://git.kernel.org/stable/c/b90d77e5fd784ada62ddd714d15ee2400c28e1cf"}],"title":"bpf: Fix remap of arena.","x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"providerMetadata":{"orgId":"af854a3a-2127-422b-91ae-364da2661108","shortName":"CVE","dateUpdated":"2024-08-02T04:54:32.802Z"},"title":"CVE Program Container","references":[{"url":"https://git.kernel.org/stable/c/87496a1b01e8e2e399428c0db25e106f7961d01e","tags":["x_transferred"]},{"url":"https://git.kernel.org/stable/c/b90d77e5fd784ada62ddd714d15ee2400c28e1cf","tags":["x_transferred"]}]},{"metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2024-42075","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"version":"2.0.3","timestamp":"2024-09-10T16:19:30.060305Z"}}}],"title":"CISA ADP Vulnrichment","providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2024-09-11T17:33:57.585Z"}}]}}