{"id":"CVE-2026-98043","state":"PUBLISHED","title":"bpf: Don't infer non-NULL from a pointer with an unbounded offset","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Don't infer non-NULL from a pointer with an unbounded offset\n\nreg_not_null() decides that a register holds a non-NULL value by\nlooking at its type alone. For pointer types that allow arithmetic the\ntype only guarantees a non-NULL base, in case of an unbound offset\nthe runtime offset value might still add up to NULL.\nConsider the followng program:\n\n  r6 = bpf_map_lookup_elem(map, &0);  /* present */\n  if (r6 == 0) return 0;\n  r7 = bpf_map_lookup_elem(map, &1);  /* absent, NULL at runtime */\n  r8 = r7;\n  r8 -= r6;     /* pointer - pointer: unknown scalar, -r6 */\n  r8 <<= 1;\n  r8 >>= 1;     /* any non-negative offset is accepted by */\n                /* check_reg_sane_offset_ptr() */\n  r6 += r8;     /* verifier: map value;    runtime: zero  */\n  if (r7 != r6) return 0;\n  *(u8 *)(r7 + 0);  /* r7 is inferred non-NULL, both are zero */\n\nAt runtime both registers are zero, the comparison is true and the\nload faults with NULL pointer dereference.\n\nRequire the offset to be within +-BPF_MAX_VAR_OFF in reg_not_null().","publishedAt":"2026-09-25T10:23:54.865Z","updatedAt":"2026-10-21T12:54:11.750Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"cac616db39c207dc63465a4e05c6ce0e60b2cce4","status":"affected","lessThan":"8b414dbe97fcefd116e5a620c3bd9993014aa4ce","versionType":"git"},{"version":"cac616db39c207dc63465a4e05c6ce0e60b2cce4","status":"affected","lessThan":"019d845a08b8ccfe8eefaaf4bca6870f2b8c58ae","versionType":"git"},{"version":"cac616db39c207dc63465a4e05c6ce0e60b2cce4","status":"affected","lessThan":"65bea674f43c09c0eda033a140dfac6a2842a19f","versionType":"git"},{"version":"cac616db39c207dc63465a4e05c6ce0e60b2cce4","status":"affected","lessThan":"cb6642048739bf4ee5aa09fe465511f1e87caa63","versionType":"git"},{"version":"cac616db39c207dc63465a4e05c6ce0e60b2cce4","status":"affected","lessThan":"67b529f521a6676cdfc78b91b0217d7eaa84216b","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["kernel/bpf/verifier.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.8","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.8","versionType":"semver"},{"version":"6.6.160","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.114","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.57","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.7","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["kernel/bpf/verifier.c"]}],"references":["https://git.kernel.org/stable/c/8b414dbe97fcefd116e5a620c3bd9993014aa4ce","https://git.kernel.org/stable/c/019d845a08b8ccfe8eefaaf4bca6870f2b8c58ae","https://git.kernel.org/stable/c/65bea674f43c09c0eda033a140dfac6a2842a19f","https://git.kernel.org/stable/c/cb6642048739bf4ee5aa09fe465511f1e87caa63","https://git.kernel.org/stable/c/67b529f521a6676cdfc78b91b0217d7eaa84216b"],"weaknesses":[],"ingestedAt":"2026-10-29T20:13:43.249Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/98xxx/CVE-2026-98043.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-98043","state":"PUBLISHED","datePublished":"2026-09-25T10:23:54.865Z","dateUpdated":"2026-10-21T12:54:11.750Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-09-25T10:19:56.071Z"},"containers":{"cna":{"title":"bpf: Don't infer non-NULL from a pointer with an unbounded offset","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Don't infer non-NULL from a pointer with an unbounded offset\n\nreg_not_null() decides that a register holds a non-NULL value by\nlooking at its type alone. For pointer types that allow arithmetic the\ntype only guarantees a non-NULL base, in case of an unbound offset\nthe runtime offset value might still add up to NULL.\nConsider the followng program:\n\n  r6 = bpf_map_lookup_elem(map, &0);  /* present */\n  if (r6 == 0) return 0;\n  r7 = bpf_map_lookup_elem(map, &1);  /* absent, NULL at runtime */\n  r8 = r7;\n  r8 -= r6;     /* pointer - pointer: unknown scalar, -r6 */\n  r8 <<= 1;\n  r8 >>= 1;     /* any non-negative offset is accepted by */\n                /* check_reg_sane_offset_ptr() */\n  r6 += r8;     /* verifier: map value;    runtime: zero  */\n  if (r7 != r6) return 0;\n  *(u8 *)(r7 + 0);  /* r7 is inferred non-NULL, both are zero */\n\nAt runtime both registers are zero, the comparison is true and the\nload faults with NULL pointer dereference.\n\nRequire the offset to be within +-BPF_MAX_VAR_OFF in reg_not_null()."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"cac616db39c207dc63465a4e05c6ce0e60b2cce4","status":"affected","lessThan":"8b414dbe97fcefd116e5a620c3bd9993014aa4ce","versionType":"git"},{"version":"cac616db39c207dc63465a4e05c6ce0e60b2cce4","status":"affected","lessThan":"019d845a08b8ccfe8eefaaf4bca6870f2b8c58ae","versionType":"git"},{"version":"cac616db39c207dc63465a4e05c6ce0e60b2cce4","status":"affected","lessThan":"65bea674f43c09c0eda033a140dfac6a2842a19f","versionType":"git"},{"version":"cac616db39c207dc63465a4e05c6ce0e60b2cce4","status":"affected","lessThan":"cb6642048739bf4ee5aa09fe465511f1e87caa63","versionType":"git"},{"version":"cac616db39c207dc63465a4e05c6ce0e60b2cce4","status":"affected","lessThan":"67b529f521a6676cdfc78b91b0217d7eaa84216b","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["kernel/bpf/verifier.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.8","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.8","versionType":"semver"},{"version":"6.6.160","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.114","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.57","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.7","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["kernel/bpf/verifier.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/8b414dbe97fcefd116e5a620c3bd9993014aa4ce"},{"url":"https://git.kernel.org/stable/c/019d845a08b8ccfe8eefaaf4bca6870f2b8c58ae"},{"url":"https://git.kernel.org/stable/c/65bea674f43c09c0eda033a140dfac6a2842a19f"},{"url":"https://git.kernel.org/stable/c/cb6642048739bf4ee5aa09fe465511f1e87caa63"},{"url":"https://git.kernel.org/stable/c/67b529f521a6676cdfc78b91b0217d7eaa84216b"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-21T12:54:11.750Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.8","versionEndExcluding":"6.6.160"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.8","versionEndExcluding":"6.12.114"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.8","versionEndExcluding":"6.18.57"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.8","versionEndExcluding":"7.2.7"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.8","versionEndExcluding":"7.3"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}