{"id":"CVE-2026-74305","state":"PUBLISHED","title":"bpf: Tighten cgroup storage cookie checks for prog arrays","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Tighten cgroup storage cookie checks for prog arrays\n\nThe fix in commit abad3d0bad72 (\"bpf: Fix oob access in cgroup local\nstorage\") is still incomplete. The prog-array compatibility check\ntreats a program with no cgroup storage as compatible with any stored\nstorage cookie. This allows a storage-less program to bridge a tail\ncall chain between an entry program and a storage-using callee even\nthough cgroup local storage at runtime still follows the caller's\ncontext, that is, A -> B(no storage) -> C(storage) path.\n\nRequiring exact cookie equality would break the legitimate case of a\nstorage-less leaf program being tail called from a storage-using one.\nInstead, only accept a zero storage cookie if the program cannot\nperform tail calls itself. This keeps A -> B(no storage) working\nwhile rejecting the A -> B(no storage) -> C(storage) bridge.","publishedAt":"2026-08-15T05:58:06.654Z","updatedAt":"2026-10-16T18:55:31.883Z","severity":{"score":7.8,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"c1c74584b9b4043c52e41fec415226e582d266a3","status":"affected","lessThan":"87177497cca90bf4fcfb759eb898560eb5b46a10","versionType":"git"},{"version":"66da7cee78590259b400e51a70622ccd41da7bb2","status":"affected","lessThan":"1c762d28698483ce7c372091f34d86e4d4828652","versionType":"git"},{"version":"7acfa07c585e3d7a64654d38f0a5c762877d0b9b","status":"affected","lessThan":"eb73056ce2a6f101ddd3bdba89af6b24ebffff85","versionType":"git"},{"version":"41688d1fc5d163a6c2c0e95c0419e2cb31a44648","status":"affected","lessThan":"9ca06849c4239aa2d580c54651f8588c51cb398b","versionType":"git"},{"version":"abad3d0bad72a52137e0c350c59542d75ae4f513","status":"affected","lessThan":"46fbafe3d2d569d828e8d24a7dbe1659f63685cf","versionType":"git"},{"version":"abad3d0bad72a52137e0c350c59542d75ae4f513","status":"affected","lessThan":"cb22dc79528eb26a46d346c3118dbd6b14c70609","versionType":"git"},{"version":"abad3d0bad72a52137e0c350c59542d75ae4f513","status":"affected","lessThan":"10627ddc0167aab5c1c390a10ef461e9937aba08","versionType":"git"},{"version":"19341d5c59e8c7e8528e40f8663e99d67810473c","status":"affected","versionType":"git"},{"version":"5.15.192","status":"affected","lessThan":"5.15.212","versionType":"semver"},{"version":"6.1.151","status":"affected","lessThan":"6.1.178","versionType":"semver"},{"version":"6.6.105","status":"affected","lessThan":"6.6.145","versionType":"semver"},{"version":"6.12.46","status":"affected","lessThan":"6.12.97","versionType":"semver"},{"version":"6.16.1","status":"affected","lessThan":"6.17","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["kernel/bpf/core.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.17","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.17","versionType":"semver"},{"version":"5.15.212","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.178","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.145","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.97","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.40","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.5","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["kernel/bpf/core.c"]}],"references":["https://git.kernel.org/stable/c/87177497cca90bf4fcfb759eb898560eb5b46a10","https://git.kernel.org/stable/c/1c762d28698483ce7c372091f34d86e4d4828652","https://git.kernel.org/stable/c/eb73056ce2a6f101ddd3bdba89af6b24ebffff85","https://git.kernel.org/stable/c/9ca06849c4239aa2d580c54651f8588c51cb398b","https://git.kernel.org/stable/c/46fbafe3d2d569d828e8d24a7dbe1659f63685cf","https://git.kernel.org/stable/c/cb22dc79528eb26a46d346c3118dbd6b14c70609","https://git.kernel.org/stable/c/10627ddc0167aab5c1c390a10ef461e9937aba08"],"weaknesses":[],"ingestedAt":"2026-10-29T20:12:58.252Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/74xxx/CVE-2026-74305.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-74305","state":"PUBLISHED","datePublished":"2026-08-15T05:58:06.654Z","dateUpdated":"2026-10-16T18:55:31.883Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-08-15T05:44:03.882Z"},"containers":{"cna":{"title":"bpf: Tighten cgroup storage cookie checks for prog arrays","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Tighten cgroup storage cookie checks for prog arrays\n\nThe fix in commit abad3d0bad72 (\"bpf: Fix oob access in cgroup local\nstorage\") is still incomplete. The prog-array compatibility check\ntreats a program with no cgroup storage as compatible with any stored\nstorage cookie. This allows a storage-less program to bridge a tail\ncall chain between an entry program and a storage-using callee even\nthough cgroup local storage at runtime still follows the caller's\ncontext, that is, A -> B(no storage) -> C(storage) path.\n\nRequiring exact cookie equality would break the legitimate case of a\nstorage-less leaf program being tail called from a storage-using one.\nInstead, only accept a zero storage cookie if the program cannot\nperform tail calls itself. This keeps A -> B(no storage) working\nwhile rejecting the A -> B(no storage) -> C(storage) bridge."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"c1c74584b9b4043c52e41fec415226e582d266a3","status":"affected","lessThan":"87177497cca90bf4fcfb759eb898560eb5b46a10","versionType":"git"},{"version":"66da7cee78590259b400e51a70622ccd41da7bb2","status":"affected","lessThan":"1c762d28698483ce7c372091f34d86e4d4828652","versionType":"git"},{"version":"7acfa07c585e3d7a64654d38f0a5c762877d0b9b","status":"affected","lessThan":"eb73056ce2a6f101ddd3bdba89af6b24ebffff85","versionType":"git"},{"version":"41688d1fc5d163a6c2c0e95c0419e2cb31a44648","status":"affected","lessThan":"9ca06849c4239aa2d580c54651f8588c51cb398b","versionType":"git"},{"version":"abad3d0bad72a52137e0c350c59542d75ae4f513","status":"affected","lessThan":"46fbafe3d2d569d828e8d24a7dbe1659f63685cf","versionType":"git"},{"version":"abad3d0bad72a52137e0c350c59542d75ae4f513","status":"affected","lessThan":"cb22dc79528eb26a46d346c3118dbd6b14c70609","versionType":"git"},{"version":"abad3d0bad72a52137e0c350c59542d75ae4f513","status":"affected","lessThan":"10627ddc0167aab5c1c390a10ef461e9937aba08","versionType":"git"},{"version":"19341d5c59e8c7e8528e40f8663e99d67810473c","status":"affected","versionType":"git"},{"version":"5.15.192","status":"affected","lessThan":"5.15.212","versionType":"semver"},{"version":"6.1.151","status":"affected","lessThan":"6.1.178","versionType":"semver"},{"version":"6.6.105","status":"affected","lessThan":"6.6.145","versionType":"semver"},{"version":"6.12.46","status":"affected","lessThan":"6.12.97","versionType":"semver"},{"version":"6.16.1","status":"affected","lessThan":"6.17","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["kernel/bpf/core.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.17","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.17","versionType":"semver"},{"version":"5.15.212","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.178","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.145","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.97","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.40","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.5","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["kernel/bpf/core.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/87177497cca90bf4fcfb759eb898560eb5b46a10"},{"url":"https://git.kernel.org/stable/c/1c762d28698483ce7c372091f34d86e4d4828652"},{"url":"https://git.kernel.org/stable/c/eb73056ce2a6f101ddd3bdba89af6b24ebffff85"},{"url":"https://git.kernel.org/stable/c/9ca06849c4239aa2d580c54651f8588c51cb398b"},{"url":"https://git.kernel.org/stable/c/46fbafe3d2d569d828e8d24a7dbe1659f63685cf"},{"url":"https://git.kernel.org/stable/c/cb22dc79528eb26a46d346c3118dbd6b14c70609"},{"url":"https://git.kernel.org/stable/c/10627ddc0167aab5c1c390a10ef461e9937aba08"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - Exploitation requires local bpf() syscalls to load cgroup BPF programs/maps, populate a prog array, attach or test-run them; per kernel guidance BPF/cgroup hooks are Local even when later triggered by sockets or packets.\nAC:L - The attacker fully controls crafting programs A/B/C, prog-array insertion order, and triggering the cgroup hook or BPF_PROG_TEST_RUN; no race or victim-dependent state is required to reach the mismatched-storage OOB path.\nPR:L - Reaching the buggy compatibility check needs only local BPF privileges (CAP_BPF or unprivileged BPF where enabled) plus cgroup attach/test-run access obtainable by unprivileged users in delegated cgroups or user namespaces, not init-namespace root.\nUI:N - The attacker loads, wires, and triggers the malicious BPF program chain itself (e.g., creating a socket or using BPF_PROG_TEST_RUN); no action by another user or administrator is required.\nS:U - The out-of-bounds cgroup local storage access corrupts kernel heap memory within the same kernel security domain and enables local privilege escalation, not a cross-boundary VM, IOMMU, or sandbox escape.\nC:H - Tail-called program C obtains a pointer from bpf_get_local_storage() backed by entry program A's smaller cgroup storage while verifier-approved helpers perform larger accesses, yielding controllable out-of-bounds kernel heap reads.\nI:H - The returned cgroup storage pointer is writable map memory, and size-mismatched helper copies (e.g., bpf_map_update_elem/copy_map_value_long) enable controllable out-of-bounds heap writes exploitable for kernel corruption and code execution.\nA:H - The heap out-of-bounds read/write can corrupt adjacent kernel objects and readily trigger kernel oops/panic or denial of service, as demonstrated by the cgroup_storage_oob selftest expecting KASAN reports without the fix."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-17T05:45:39.394Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.15.192","versionEndExcluding":"5.15.212"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.1.151","versionEndExcluding":"6.1.178"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.6.105","versionEndExcluding":"6.6.145"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.12.46","versionEndExcluding":"6.12.97"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.17","versionEndExcluding":"6.18.40"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.17","versionEndExcluding":"7.1.5"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.17","versionEndExcluding":"7.2"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.16.1"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2026-74305","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"version":"2.0.3","timestamp":"2026-10-16T18:52:53.092866Z"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-16T18:55:31.883Z"}}]}}}