{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2024-50253","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2024-10-21T19:36:19.979Z","datePublished":"2024-11-09T10:15:06.891Z","dateUpdated":"2026-08-05T11:42:47.547Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-08-05T11:42:47.547Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Check the validity of nr_words in bpf_iter_bits_new()\n\nCheck the validity of nr_words in bpf_iter_bits_new(). Without this\ncheck, when multiplication overflow occurs for nr_bits (e.g., when\nnr_words = 0x0400-0001, nr_bits becomes 64), stack corruption may occur\ndue to bpf_probe_read_kernel_common(..., nr_bytes = 0x2000-0008).\n\nFix it by limiting the maximum value of nr_words to 511. The value is\nderived from the current implementation of BPF memory allocator. To\nensure compatibility if the BPF memory allocator's size limitation\nchanges in the future, use the helper bpf_mem_alloc_check_size() to\ncheck whether nr_bytes is too larger. And return -E2BIG instead of\n-ENOMEM for oversized nr_bytes."}],"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 by loading and running an eBPF program via the bpf(2) syscall, which requires local system access. Per kernel CNA guidance, BPF subsystem bugs are Local.\nAC:L - Triggering is fully deterministic — the attacker simply calls bpf_iter_bits_new() with nr_words = 0x04000001, requiring no race, no memory-layout grooming, and no non-default configuration. The kfunc is in the COMMON kfunc set, available to every BPF program type on any stock kernel with CONFIG_DEBUG_INFO_BTF.\nPR:L - Calling the kfunc requires bpf_capable(), which is satisfied by an unprivileged container process holding a delegated BPF token (bpffs delegate_cmds/delegate_progs grants ns_capable(CAP_BPF) inside a user namespace) or by any non-root CAP_BPF-only daemon such as a tracing/observability or Cilium-style agent. CAP_BPF is a deliberately non-root, delegable capability, so this is Low rather than High privilege.\nUI:N - The attacker loads and triggers its own BPF program end to end; no victim action, mount, or file open is involved.\nS:U - The corruption stays within the kernel's own security authority — this is a standard local kernel memory-corruption/privilege-escalation primitive with no VM, IOMMU, or sandbox boundary crossed.\nC:H - The attacker supplies an arbitrary kernel source address whose contents are copied far past the 8-byte destination, and the resulting large-scale kernel memory corruption can be leveraged to disclose sensitive kernel data. Per guidance, out-of-bounds access of this magnitude is High.\nI:H - This is an unbounded out-of-bounds write of 512 MB to 3.5 GB starting at an 8-byte kernel-stack object, overwriting saved registers and return addresses with either attacker-chosen kernel memory contents or zeros; the commit itself states \"stack corruption may occur.\" Such corruption is exploitable for control-flow hijacking and, on non-VMAP_STACK builds, zeroes adjacent kernel structures including credentials.\nA:H - Even the failure path unconditionally executes memset(dst, 0, 512MB) over the kernel stack, so the frame is destroyed and the write runs into the VMAP_STACK guard page, guaranteeing an oops or panic. The attacker can repeat this at will."}]}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["kernel/bpf/helpers.c"],"versions":[{"version":"4665415975b0827e9646cab91c61d02a6b364d59","lessThan":"c9539e09c67880ecd88b51188c346a2cc078b06c","status":"affected","versionType":"git"},{"version":"4665415975b0827e9646cab91c61d02a6b364d59","lessThan":"393397fbdcad7396639d7077c33f86169184ba99","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/helpers.c"],"versions":[{"version":"6.11","status":"affected"},{"version":"0","lessThan":"6.11","status":"unaffected","versionType":"semver"},{"version":"6.11.7","lessThanOrEqual":"6.11.*","status":"unaffected","versionType":"semver"},{"version":"6.12","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":"6.11","versionEndExcluding":"6.11.7"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.11","versionEndExcluding":"6.12"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/c9539e09c67880ecd88b51188c346a2cc078b06c"},{"url":"https://git.kernel.org/stable/c/393397fbdcad7396639d7077c33f86169184ba99"}],"title":"bpf: Check the validity of nr_words in bpf_iter_bits_new()","x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"metrics":[{"cvssV3_1":{"scope":"UNCHANGED","version":"3.1","baseScore":5.5,"attackVector":"LOCAL","baseSeverity":"MEDIUM","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","integrityImpact":"NONE","userInteraction":"NONE","attackComplexity":"LOW","availabilityImpact":"HIGH","privilegesRequired":"LOW","confidentialityImpact":"NONE"}},{"other":{"type":"ssvc","content":{"id":"CVE-2024-50253","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"version":"2.0.3","timestamp":"2025-10-01T20:15:44.047457Z"}}}],"problemTypes":[{"descriptions":[{"lang":"en","type":"CWE","description":"CWE-noinfo Not enough information"}]}],"title":"CISA ADP Vulnrichment","providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2025-10-01T20:17:24.826Z"}}]}}