{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-72111", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-08-09T03:40:39.906Z", "datePublished": "2026-08-15T05:52:52.538Z", "dateUpdated": "2026-10-16T18:44:56.296Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-17T05:40:25.647Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Reset register bounds before narrowing retval range in check_mem_access()\n\nWhen the BPF verifier processes a context load of an LSM hook return\nvalue, it calls __mark_reg_s32_range() to narrow the register to the\nhook's valid range. However, __mark_reg_s32_range() intersects the new\nrange with the register's existing bounds using max_t()/min_t() rather\nthan replacing them.\n\nIf the destination register carries stale bounds from a prior instruction\n(e.g. BPF_MOV64_IMM), the intersection can produce a range narrower than\nreality. The verifier then believes it knows the register's exact value,\nwhile at runtime the actual hook return value is loaded, creating a\nverifier/runtime mismatch that can be used to bypass BPF memory safety\nchecks.\n\nThe else branch already calls mark_reg_unknown() to reset register state\nbefore any narrowing. Apply the same reset in the is_retval path so\nstale bounds are cleared before __mark_reg_s32_range() intersects." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H", "baseScore": 8.8, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - The flaw is reached only through bpf(BPF_PROG_LOAD) during bpf_check()->check_mem_access() when a BPF_LSM_MAC program loads the LSM hook return value from PTR_TO_CTX; per kernel CNA guidance BPF verifier issues are Local even if attached programs later run on file, socket, or network LSM hooks.\nAC:L - An attacker fully controls the BPF instruction sequence (e.g., BPF_MOV64_IMM to leave stale bounds, then a ctx retval load) and can deterministically force __mark_reg_s32_range() to intersect into an overly narrow range without races, special memory layout, or other uncontrollable conditions.\nPR:L - Loading BPF_PROG_TYPE_LSM programs requires CAP_BPF and CAP_PERFMON (is_perfmon_prog_type), both blocked for unprivileged users when kernel.unprivileged_bpf_disabled is set but obtainable inside user namespaces on typical CONFIG_BPF_LSM systems per kernel CNA BPF guidance.\nUI:N - No victim interaction is required; the attacker loads, verifies, and attaches their own malicious BPF LSM program and triggers the attached LSM hook with their own local syscalls or network operations.\nS:C - A container or user-namespace tenant with namespace-granted CAP_BPF can load a verifier-bypassing BPF LSM program whose runtime memory corruption executes in host kernel context on LSM hook firing, crossing the container-to-host security boundary on multi-tenant cloud and Android-style deployments.\nC:H - The verifier/runtime register-bounds mismatch lets unsafe BPF programs pass verification and perform out-of-bounds reads on ctx, stack, or map memory at runtime, a memory-corruption primitive that can be developed into arbitrary kernel memory disclosure.\nI:H - False exact-knowledge of the LSM return-value register enables verifier-approved pointer arithmetic and memory writes that are invalid at runtime, enabling out-of-bounds writes and control-flow hijacking toward arbitrary kernel code execution from BPF context.\nA:H - Running verifier-incorrect BPF LSM programs can trigger kernel oops or panic from corrupted memory accesses, and once attached the attacker can repeatedly invoke the hook to cause repeatable host-wide denial of service." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "kernel/bpf/verifier.c" ], "versions": [ { "version": "5d99e198be279045e6ecefe220f5c52f8ce9bfd5", "lessThan": "bde92f65042ec14389782dd223f706bf6b59ce5d", "status": "affected", "versionType": "git" }, { "version": "5d99e198be279045e6ecefe220f5c52f8ce9bfd5", "lessThan": "0993dc5fc619c0b25ab1310cb11d65e78351c0fe", "status": "affected", "versionType": "git" }, { "version": "5d99e198be279045e6ecefe220f5c52f8ce9bfd5", "lessThan": "5a55f9aecc08990940e70f0c7048a80850c5a16a", "status": "affected", "versionType": "git" }, { "version": "5d99e198be279045e6ecefe220f5c52f8ce9bfd5", "lessThan": "5e0b273e0a62cc04ec338c7b502797c66c2ed42a", "status": "affected", "versionType": "git" }, { "version": "1050727d83e70449991c29dd1cf29fe936a63da3", "status": "affected", "versionType": "git" }, { "version": "27ca3e20fe80be85a92b10064dfeb56cb2564b1c", "status": "affected", "versionType": "git" }, { "version": "6.10.13", "lessThan": "6.11", "status": "affected", "versionType": "semver" }, { "version": "6.11.2", "lessThan": "6.12", "status": "affected", "versionType": "semver" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "kernel/bpf/verifier.c" ], "versions": [ { "version": "6.12", "status": "affected" }, { "version": "0", "lessThan": "6.12", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.103", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.40", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1.5", "lessThanOrEqual": "7.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2", "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": "6.12", "versionEndExcluding": "6.12.103" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.12", "versionEndExcluding": "6.18.40" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.12", "versionEndExcluding": "7.1.5" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.12", "versionEndExcluding": "7.2" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.10.13" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.11.2" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/bde92f65042ec14389782dd223f706bf6b59ce5d" }, { "url": "https://git.kernel.org/stable/c/0993dc5fc619c0b25ab1310cb11d65e78351c0fe" }, { "url": "https://git.kernel.org/stable/c/5a55f9aecc08990940e70f0c7048a80850c5a16a" }, { "url": "https://git.kernel.org/stable/c/5e0b273e0a62cc04ec338c7b502797c66c2ed42a" } ], "title": "bpf: Reset register bounds before narrowing retval range in check_mem_access()", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "metrics": [ { "other": { "type": "ssvc", "content": { "id": "CVE-2026-72111", "role": "CISA Coordinator", "options": [ { "Exploitation": "none" }, { "Automatable": "no" }, { "Technical Impact": "total" } ], "version": "2.0.3", "timestamp": "2026-10-16T18:41:38.213605Z" } } } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-10-16T18:44:56.296Z" } } ] } }