{"id":"CVE-2026-43333","state":"PUBLISHED","title":"bpf: reject direct access to nullable PTR_TO_BUF pointers","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: reject direct access to nullable PTR_TO_BUF pointers\n\ncheck_mem_access() matches PTR_TO_BUF via base_type() which strips\nPTR_MAYBE_NULL, allowing direct dereference without a null check.\n\nMap iterator ctx->key and ctx->value are PTR_TO_BUF | PTR_MAYBE_NULL.\nOn stop callbacks these are NULL, causing a kernel NULL dereference.\n\nAdd a type_may_be_null() guard to the PTR_TO_BUF branch, matching the\nexisting PTR_TO_BTF_ID pattern.","publishedAt":"2026-05-08T13:31:20.107Z","updatedAt":"2026-05-23T16:06:46.060Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"b453361384c2db1c703dacb806d5fd36aec4ceca","status":"affected","lessThan":"10bc4a4dcded509c5d5c67d497900c3922c604cd","versionType":"git"},{"version":"20b2aff4bc15bda809f994761d5719827d66c0b4","status":"affected","lessThan":"21a10c06ffae24cb01fd174a7ab7736001d2ea56","versionType":"git"},{"version":"20b2aff4bc15bda809f994761d5719827d66c0b4","status":"affected","lessThan":"8755066f7bd0f4ac46a29d1708c7b20894539252","versionType":"git"},{"version":"20b2aff4bc15bda809f994761d5719827d66c0b4","status":"affected","lessThan":"70abd9d118da2f56beb4ec22e3a29becae373535","versionType":"git"},{"version":"20b2aff4bc15bda809f994761d5719827d66c0b4","status":"affected","lessThan":"63276547debc4d8a73eefb2c5273b2a905c961b0","versionType":"git"},{"version":"20b2aff4bc15bda809f994761d5719827d66c0b4","status":"affected","lessThan":"4f6c99dc0420f1a3d671c1b8ab8a7ac84d9cba09","versionType":"git"},{"version":"20b2aff4bc15bda809f994761d5719827d66c0b4","status":"affected","lessThan":"b0db1accbc7395657c2b79db59fa9fae0d6656f3","versionType":"git"},{"version":"e982070f8970bb62e69ed7c9cafff886ed200349","status":"affected","versionType":"git"},{"version":"5.15.37","status":"affected","lessThan":"5.15.203","versionType":"semver"},{"version":"5.16.11","status":"affected","lessThan":"5.17","versionType":"semver"}],"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":"5.17","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.17","versionType":"semver"},{"version":"5.15.203","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.168","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.134","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.81","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.22","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"6.19.12","status":"unaffected","lessThanOrEqual":"6.19.*","versionType":"semver"},{"version":"7.0","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/10bc4a4dcded509c5d5c67d497900c3922c604cd","https://git.kernel.org/stable/c/21a10c06ffae24cb01fd174a7ab7736001d2ea56","https://git.kernel.org/stable/c/8755066f7bd0f4ac46a29d1708c7b20894539252","https://git.kernel.org/stable/c/70abd9d118da2f56beb4ec22e3a29becae373535","https://git.kernel.org/stable/c/63276547debc4d8a73eefb2c5273b2a905c961b0","https://git.kernel.org/stable/c/4f6c99dc0420f1a3d671c1b8ab8a7ac84d9cba09","https://git.kernel.org/stable/c/b0db1accbc7395657c2b79db59fa9fae0d6656f3"],"weaknesses":[],"ingestedAt":"2026-10-29T20:11:57.932Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/43xxx/CVE-2026-43333.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-43333","state":"PUBLISHED","datePublished":"2026-05-08T13:31:20.107Z","dateUpdated":"2026-05-23T16:06:46.060Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-05-01T14:12:56.002Z"},"containers":{"cna":{"title":"bpf: reject direct access to nullable PTR_TO_BUF pointers","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: reject direct access to nullable PTR_TO_BUF pointers\n\ncheck_mem_access() matches PTR_TO_BUF via base_type() which strips\nPTR_MAYBE_NULL, allowing direct dereference without a null check.\n\nMap iterator ctx->key and ctx->value are PTR_TO_BUF | PTR_MAYBE_NULL.\nOn stop callbacks these are NULL, causing a kernel NULL dereference.\n\nAdd a type_may_be_null() guard to the PTR_TO_BUF branch, matching the\nexisting PTR_TO_BTF_ID pattern."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"b453361384c2db1c703dacb806d5fd36aec4ceca","status":"affected","lessThan":"10bc4a4dcded509c5d5c67d497900c3922c604cd","versionType":"git"},{"version":"20b2aff4bc15bda809f994761d5719827d66c0b4","status":"affected","lessThan":"21a10c06ffae24cb01fd174a7ab7736001d2ea56","versionType":"git"},{"version":"20b2aff4bc15bda809f994761d5719827d66c0b4","status":"affected","lessThan":"8755066f7bd0f4ac46a29d1708c7b20894539252","versionType":"git"},{"version":"20b2aff4bc15bda809f994761d5719827d66c0b4","status":"affected","lessThan":"70abd9d118da2f56beb4ec22e3a29becae373535","versionType":"git"},{"version":"20b2aff4bc15bda809f994761d5719827d66c0b4","status":"affected","lessThan":"63276547debc4d8a73eefb2c5273b2a905c961b0","versionType":"git"},{"version":"20b2aff4bc15bda809f994761d5719827d66c0b4","status":"affected","lessThan":"4f6c99dc0420f1a3d671c1b8ab8a7ac84d9cba09","versionType":"git"},{"version":"20b2aff4bc15bda809f994761d5719827d66c0b4","status":"affected","lessThan":"b0db1accbc7395657c2b79db59fa9fae0d6656f3","versionType":"git"},{"version":"e982070f8970bb62e69ed7c9cafff886ed200349","status":"affected","versionType":"git"},{"version":"5.15.37","status":"affected","lessThan":"5.15.203","versionType":"semver"},{"version":"5.16.11","status":"affected","lessThan":"5.17","versionType":"semver"}],"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":"5.17","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.17","versionType":"semver"},{"version":"5.15.203","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.168","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.134","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.81","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.22","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"6.19.12","status":"unaffected","lessThanOrEqual":"6.19.*","versionType":"semver"},{"version":"7.0","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/10bc4a4dcded509c5d5c67d497900c3922c604cd"},{"url":"https://git.kernel.org/stable/c/21a10c06ffae24cb01fd174a7ab7736001d2ea56"},{"url":"https://git.kernel.org/stable/c/8755066f7bd0f4ac46a29d1708c7b20894539252"},{"url":"https://git.kernel.org/stable/c/70abd9d118da2f56beb4ec22e3a29becae373535"},{"url":"https://git.kernel.org/stable/c/63276547debc4d8a73eefb2c5273b2a905c961b0"},{"url":"https://git.kernel.org/stable/c/4f6c99dc0420f1a3d671c1b8ab8a7ac84d9cba09"},{"url":"https://git.kernel.org/stable/c/b0db1accbc7395657c2b79db59fa9fae0d6656f3"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-05-23T16:06:46.060Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.15.37","versionEndExcluding":"5.15.203"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.17","versionEndExcluding":"6.1.168"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.17","versionEndExcluding":"6.6.134"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.17","versionEndExcluding":"6.12.81"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.17","versionEndExcluding":"6.18.22"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.17","versionEndExcluding":"6.19.12"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.17","versionEndExcluding":"7.0"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.16.11"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}