{"id":"CVE-2026-80956","summary":"dm-pcache: only hand out initialized cache segments","details":"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-\u003en_segs, the\nphysical device segment count, but cache_segs_init() only initializes\nthe first cache_info-\u003en_segs segments. A crafted image with\ncache_info-\u003en_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-\u003en_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.","modified":"2026-09-13T03:46:54.938990016Z","published":"2026-09-11T19:42:24.541Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/80xxx/CVE-2026-80956.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/2df0fc042e299bae3c0f60ea5cd2af9285658e9f"},{"type":"WEB","url":"https://git.kernel.org/stable/c/692037ae1a7cfacc2f0c22c6e034c1dfee0e553f"},{"type":"WEB","url":"https://git.kernel.org/stable/c/83e3116283ed2c6a6a1fa662862a4b4d7d2701a2"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/80xxx/CVE-2026-80956.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-80956"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"1d57628ff95b32d5cfa8d8f50e07690c161e9cf0"},{"fixed":"83e3116283ed2c6a6a1fa662862a4b4d7d2701a2"},{"fixed":"692037ae1a7cfacc2f0c22c6e034c1dfee0e553f"},{"fixed":"2df0fc042e299bae3c0f60ea5cd2af9285658e9f"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-80956.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"6.18.0"},{"fixed":"6.18.50"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.2.4"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-80956.json"}}],"schema_version":"1.9.0"}