{"id":"CVE-2026-98149","state":"PUBLISHED","title":"bpf: Fix percpu map update indexing with sparse CPU IDs","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Fix percpu map update indexing with sparse CPU IDs\n\nPer-CPU array, hash, and cgroup storage map updates without BPF_F_CPU\nor BPF_F_ALL_CPUS use a value buffer whose per-CPU slots are packed in\npossible-CPU order. The buffer is sized as:\n\n  round_up(value_size, 8) * num_possible_cpus()\n\nThe update paths iterate over possible CPUs, but use the logical CPU ID\nto calculate the source offset:\n\n  value + size * cpu\n\nThis only works when possible CPU IDs are contiguous starting at zero.\n\nFor example, with a possible CPU mask of 0,2-3, the buffer contains\nthree slots corresponding to CPUs 0, 2, and 3. CPU2 is therefore\nexpected to use slot 1 and CPU3 slot 2. Instead, the current code uses\nslots 2 and 3 respectively, causing incorrect per-CPU values and an\nout-of-bounds read from the update buffer for CPU3.\n\nThe corresponding lookup paths already use a dense offset while\niterating over possible CPUs. Do the same for the array, hash, and\ncgroup storage update paths, advancing the source offset once for each\npossible CPU. BPF_F_ALL_CPUS continues to use the same value for every\nCPU.","publishedAt":"2026-09-25T10:36:22.182Z","updatedAt":"2026-10-19T09:14:42.350Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"8eb76cb03f0f6c2bd7b15cf45dcffcd6bd07a360","status":"affected","lessThan":"c16c62c91e5d6737a9fbb0a541b8b34610470a2b","versionType":"git"},{"version":"8eb76cb03f0f6c2bd7b15cf45dcffcd6bd07a360","status":"affected","lessThan":"75b0a6db4300e4c2c9e97a0848deaa7acfb42fb7","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["kernel/bpf/arraymap.c","kernel/bpf/hashtab.c","kernel/bpf/local_storage.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"7.0","status":"affected"},{"version":"0","status":"unaffected","lessThan":"7.0","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/arraymap.c","kernel/bpf/hashtab.c","kernel/bpf/local_storage.c"]}],"references":["https://git.kernel.org/stable/c/c16c62c91e5d6737a9fbb0a541b8b34610470a2b","https://git.kernel.org/stable/c/75b0a6db4300e4c2c9e97a0848deaa7acfb42fb7"],"weaknesses":[],"ingestedAt":"2026-10-29T20:13:43.249Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/98xxx/CVE-2026-98149.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-98149","state":"PUBLISHED","datePublished":"2026-09-25T10:36:22.182Z","dateUpdated":"2026-10-19T09:14:42.350Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-09-25T10:25:14.320Z"},"containers":{"cna":{"title":"bpf: Fix percpu map update indexing with sparse CPU IDs","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Fix percpu map update indexing with sparse CPU IDs\n\nPer-CPU array, hash, and cgroup storage map updates without BPF_F_CPU\nor BPF_F_ALL_CPUS use a value buffer whose per-CPU slots are packed in\npossible-CPU order. The buffer is sized as:\n\n  round_up(value_size, 8) * num_possible_cpus()\n\nThe update paths iterate over possible CPUs, but use the logical CPU ID\nto calculate the source offset:\n\n  value + size * cpu\n\nThis only works when possible CPU IDs are contiguous starting at zero.\n\nFor example, with a possible CPU mask of 0,2-3, the buffer contains\nthree slots corresponding to CPUs 0, 2, and 3. CPU2 is therefore\nexpected to use slot 1 and CPU3 slot 2. Instead, the current code uses\nslots 2 and 3 respectively, causing incorrect per-CPU values and an\nout-of-bounds read from the update buffer for CPU3.\n\nThe corresponding lookup paths already use a dense offset while\niterating over possible CPUs. Do the same for the array, hash, and\ncgroup storage update paths, advancing the source offset once for each\npossible CPU. BPF_F_ALL_CPUS continues to use the same value for every\nCPU."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"8eb76cb03f0f6c2bd7b15cf45dcffcd6bd07a360","status":"affected","lessThan":"c16c62c91e5d6737a9fbb0a541b8b34610470a2b","versionType":"git"},{"version":"8eb76cb03f0f6c2bd7b15cf45dcffcd6bd07a360","status":"affected","lessThan":"75b0a6db4300e4c2c9e97a0848deaa7acfb42fb7","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["kernel/bpf/arraymap.c","kernel/bpf/hashtab.c","kernel/bpf/local_storage.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"7.0","status":"affected"},{"version":"0","status":"unaffected","lessThan":"7.0","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/arraymap.c","kernel/bpf/hashtab.c","kernel/bpf/local_storage.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/c16c62c91e5d6737a9fbb0a541b8b34610470a2b"},{"url":"https://git.kernel.org/stable/c/75b0a6db4300e4c2c9e97a0848deaa7acfb42fb7"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-19T09:14:42.350Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"7.0","versionEndExcluding":"7.2.7"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"7.0","versionEndExcluding":"7.3"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}