{ "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" } } ] } }