{"id":"CVE-2025-40143","summary":"bpf: dont report verifier bug for missing bpf_scc_visit on speculative path","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: dont report verifier bug for missing bpf_scc_visit on speculative path\n\nSyzbot generated a program that triggers a verifier_bug() call in\nmaybe_exit_scc(). maybe_exit_scc() assumes that, when called for a\nstate with insn_idx in some SCC, there should be an instance of struct\nbpf_scc_visit allocated for that SCC. Turns out the assumption does\nnot hold for speculative execution paths. See example in the next\npatch.\n\nmaybe_scc_exit() is called from update_branch_counts() for states that\nreach branch count of zero, meaning that path exploration for a\nparticular path is finished. Path exploration can finish in one of\nthree ways:\na. Verification error is found. In this case, update_branch_counts()\n   is called only for non-speculative paths.\nb. Top level BPF_EXIT is reached. Such instructions are never a part of\n   an SCC, so compute_scc_callchain() in maybe_scc_exit() will return\n   false, and maybe_scc_exit() will return early.\nc. A checkpoint is reached and matched. Checkpoints are created by\n   is_state_visited(), which calls maybe_enter_scc(), which allocates\n   bpf_scc_visit instances for checkpoints within SCCs.\n\nHence, for non-speculative symbolic execution paths, the assumption\nstill holds: if maybe_scc_exit() is called for a state within an SCC,\nbpf_scc_visit instance must exist.\n\nThis patch removes the verifier_bug() call for speculative paths.","modified":"2026-03-20T12:43:11.494809Z","published":"2025-11-12T10:23:25.489Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/40xxx/CVE-2025-40143.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/3861e7c4324aa20a632fb74eb3904114f6afdb57"},{"type":"WEB","url":"https://git.kernel.org/stable/c/a3c73d629ea1373af3c0c954d41fd1af555492e3"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/40xxx/CVE-2025-40143.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-40143"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"c9e31900b54cadf5398dfb838c0a63effa1defec"},{"fixed":"3861e7c4324aa20a632fb74eb3904114f6afdb57"},{"fixed":"a3c73d629ea1373af3c0c954d41fd1af555492e3"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2025-40143.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"6.17.0"},{"fixed":"6.17.3"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2025-40143.json"}}],"schema_version":"1.7.5"}