{ "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" } } ] } }