{"id":"CVE-2026-31413","summary":"bpf: Fix unsound scalar forking in maybe_fork_scalars() for BPF_OR","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Fix unsound scalar forking in maybe_fork_scalars() for BPF_OR\n\nmaybe_fork_scalars() is called for both BPF_AND and BPF_OR when the\nsource operand is a constant.  When dst has signed range [-1, 0], it\nforks the verifier state: the pushed path gets dst = 0, the current\npath gets dst = -1.\n\nFor BPF_AND this is correct: 0 & K == 0.\nFor BPF_OR this is wrong:    0 | K == K, not 0.\n\nThe pushed path therefore tracks dst as 0 when the runtime value is K,\nproducing an exploitable verifier/runtime divergence that allows\nout-of-bounds map access.\n\nFix this by passing env-\u003einsn_idx (instead of env-\u003einsn_idx + 1) to\npush_stack(), so the pushed path re-executes the ALU instruction with\ndst = 0 and naturally computes the correct result for any opcode.","modified":"2026-04-14T05:03:16.621921Z","published":"2026-04-12T05:36:14.632Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/31xxx/CVE-2026-31413.json"},"references":[{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"},{"type":"WEB","url":"https://git.kernel.org/stable/c/342aa1ee995ef5bbf876096dc3a5e51218d76fa4"},{"type":"WEB","url":"https://git.kernel.org/stable/c/58bd87d0e69204dbd739e4387a1edb0c4b1644e7"},{"type":"WEB","url":"https://git.kernel.org/stable/c/c845894ebd6fb43226b3118d6b017942550910c5"},{"type":"WEB","url":"https://git.kernel.org/stable/c/d13281ae7ea8902b21d99d10a2c8caf0bdec0455"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/31xxx/CVE-2026-31413.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-31413"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"dea9989a3f3961faede93752cd81eb5a9514d911"},{"fixed":"342aa1ee995ef5bbf876096dc3a5e51218d76fa4"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"4c122e8ae14950cf6b59d208fc5160f7c601e746"},{"fixed":"58bd87d0e69204dbd739e4387a1edb0c4b1644e7"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"e52567173ba86dbffb990595fbe60e2e83899372"},{"fixed":"d13281ae7ea8902b21d99d10a2c8caf0bdec0455"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"bffacdb80b93b7b5e96b26fad64cc490a6c7d6c7"},{"fixed":"c845894ebd6fb43226b3118d6b017942550910c5"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-31413.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"6.12.75"},{"fixed":"6.12.80"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.18.16"},{"fixed":"6.18.21"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.6"},{"fixed":"6.19.11"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-31413.json"}}],"schema_version":"1.7.5"}