{"id":"CVE-2026-80956","state":"PUBLISHED","title":"dm-pcache: only hand out initialized cache segments","description":"In the Linux kernel, the following vulnerability has been resolved:\n\ndm-pcache: only hand out initialized cache segments\n\nget_cache_segment() scans the segment map up to cache->n_segs, the\nphysical device segment count, but cache_segs_init() only initializes\nthe first cache_info->n_segs segments. A crafted image with\ncache_info->n_segs smaller than the device count leaves the remaining\npcache_cache_segment structs zeroed (segment.data == NULL), and the\nallocator can hand one to cache_kset_close(), which writes through the\nreturned segment's data pointer with no NULL check.\n\nBound the allocator's search to cache_info->n_segs so only initialized\nsegments are ever returned. A conforming cache sets n_segs equal to the\ndevice segment count, so this rejects nothing legitimate.","publishedAt":"2026-09-11T19:42:24.541Z","updatedAt":"2026-10-19T08:45:40.093Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"1d57628ff95b32d5cfa8d8f50e07690c161e9cf0","status":"affected","lessThan":"83e3116283ed2c6a6a1fa662862a4b4d7d2701a2","versionType":"git"},{"version":"1d57628ff95b32d5cfa8d8f50e07690c161e9cf0","status":"affected","lessThan":"692037ae1a7cfacc2f0c22c6e034c1dfee0e553f","versionType":"git"},{"version":"1d57628ff95b32d5cfa8d8f50e07690c161e9cf0","status":"affected","lessThan":"2df0fc042e299bae3c0f60ea5cd2af9285658e9f","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/md/dm-pcache/cache_segment.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.18","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.18","versionType":"semver"},{"version":"6.18.50","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.4","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":["drivers/md/dm-pcache/cache_segment.c"]}],"references":["https://git.kernel.org/stable/c/83e3116283ed2c6a6a1fa662862a4b4d7d2701a2","https://git.kernel.org/stable/c/692037ae1a7cfacc2f0c22c6e034c1dfee0e553f","https://git.kernel.org/stable/c/2df0fc042e299bae3c0f60ea5cd2af9285658e9f"],"weaknesses":[],"ingestedAt":"2026-10-29T20:13:07.220Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/80xxx/CVE-2026-80956.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-80956","state":"PUBLISHED","datePublished":"2026-09-11T19:42:24.541Z","dateUpdated":"2026-10-19T08:45:40.093Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-08-26T14:34:25.804Z"},"containers":{"cna":{"title":"dm-pcache: only hand out initialized cache segments","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\ndm-pcache: only hand out initialized cache segments\n\nget_cache_segment() scans the segment map up to cache->n_segs, the\nphysical device segment count, but cache_segs_init() only initializes\nthe first cache_info->n_segs segments. A crafted image with\ncache_info->n_segs smaller than the device count leaves the remaining\npcache_cache_segment structs zeroed (segment.data == NULL), and the\nallocator can hand one to cache_kset_close(), which writes through the\nreturned segment's data pointer with no NULL check.\n\nBound the allocator's search to cache_info->n_segs so only initialized\nsegments are ever returned. A conforming cache sets n_segs equal to the\ndevice segment count, so this rejects nothing legitimate."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"1d57628ff95b32d5cfa8d8f50e07690c161e9cf0","status":"affected","lessThan":"83e3116283ed2c6a6a1fa662862a4b4d7d2701a2","versionType":"git"},{"version":"1d57628ff95b32d5cfa8d8f50e07690c161e9cf0","status":"affected","lessThan":"692037ae1a7cfacc2f0c22c6e034c1dfee0e553f","versionType":"git"},{"version":"1d57628ff95b32d5cfa8d8f50e07690c161e9cf0","status":"affected","lessThan":"2df0fc042e299bae3c0f60ea5cd2af9285658e9f","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/md/dm-pcache/cache_segment.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.18","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.18","versionType":"semver"},{"version":"6.18.50","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.4","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":["drivers/md/dm-pcache/cache_segment.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/83e3116283ed2c6a6a1fa662862a4b4d7d2701a2"},{"url":"https://git.kernel.org/stable/c/692037ae1a7cfacc2f0c22c6e034c1dfee0e553f"},{"url":"https://git.kernel.org/stable/c/2df0fc042e299bae3c0f60ea5cd2af9285658e9f"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-19T08:45:40.093Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.18","versionEndExcluding":"6.18.50"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.18","versionEndExcluding":"7.2.4"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.18","versionEndExcluding":"7.3"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}