{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-80962", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-08-26T14:34:25.809Z", "datePublished": "2026-09-11T19:42:28.500Z", "dateUpdated": "2026-10-19T08:45:46.216Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-19T08:45:46.216Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ndm-pcache: validate geometry fields from on-disk cache_info\n\ncache_segs_init() iterates cache_info->n_segs times indexing\ncache->segments[], which is sized to the cache device geometry, and\nget_seg_id() takes each segment id from the on-media cache_info and the\nper-segment next_seg link. Both come from cache device metadata that is\nonly CRC-protected with a fixed public seed, so whoever supplies the\ncache device on a table load (CAP_SYS_ADMIN) controls them: an oversized\nn_segs or an out-of-range id drives an out-of-bounds access of\ncache->segments[] and a wild CACHE_DEV_SEGMENT() pointer into the device\nmapping -- an out-of-bounds read and write from on-disk data.\n\nReject an n_segs that exceeds the device segment count and a segment id\nthat is out of range before either is used. Valid metadata is unaffected." } ], "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 - The OOB access is reached only through a local device-mapper table load on /dev/mapper/control (ctl_ioctl → table_load → populate_table → dm_pcache_ctr → pcache_start → pcache_cache_start → cache_segs_init/get_seg_id). No network, Bluetooth, or USB path feeds on-disk cache_info geometry.\nAC:L - The attacker fully controls on-media cache_info.n_segs, cache_info.seg_id and each segment next_seg, and can forge a passing CRC because PCACHE_CRC_SEED (0x3B15A) is public, so a crafted INIT_DONE image with oversized n_segs or out-of-range ids hits the OOB on every table load with no race.\nPR:L - ctl_ioctl gates DM_TABLE_LOAD with capable(CAP_SYS_ADMIN). In the most severe reasonable deployment that capability is held by a container or storage-stack administrator with delegated mapper and DAX/pmem nodes rather than exclusive host root, which kernel-CNA scoring of device-mapper table-load bugs maps to Low.\nUI:N - The attacker crafts the DAX cache-device metadata and issues DM_TABLE_LOAD themselves; no separate victim must mount a filesystem, open a file, or otherwise interact.\nS:U - Out-of-bounds indexing of cache->segments[] and wild CACHE_DEV_SEGMENT() pointers corrupt kernel memory on the same host that loaded the table. This stays within one kernel security authority and is not a VM escape or IOMMU bypass.\nC:H - An out-of-range seg_id makes CACHE_DEV_SEGMENT() point past the DAX mapping into kernel memory, and cache_seg_meta_load() copy_mc_to_kernel's that region; oversized n_segs also reads past the kvalloc'd segments[] array. That kernel memory-corruption read primitive is Confidentiality High.\nI:H - cache_seg_init() writes pcache_cache_segment fields past the kvalloc'd cache->segments[] when n_segs exceeds seg_num, and a wild CACHE_DEV_SEGMENT() is later written through memcpy_flushcache/memset. That out-of-bounds kernel write is Integrity High and exploitable for code execution.\nA:H - Heap overflow of cache->segments[] or dereference of a mapping-relative pointer past the DAX device causes a kernel oops or panic at table load, fully denying availability." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/md/dm-pcache/cache.c" ], "versions": [ { "version": "1d57628ff95b32d5cfa8d8f50e07690c161e9cf0", "lessThan": "ab5dcde6fa96bc115b85f3621c60e39c66229a90", "status": "affected", "versionType": "git" }, { "version": "1d57628ff95b32d5cfa8d8f50e07690c161e9cf0", "lessThan": "3e19172089ec81132a8a48e802b1034a744209f4", "status": "affected", "versionType": "git" }, { "version": "1d57628ff95b32d5cfa8d8f50e07690c161e9cf0", "lessThan": "32d1809da31094ef76fd98dc1f1a8b55ca1295dd", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/md/dm-pcache/cache.c" ], "versions": [ { "version": "6.18", "status": "affected" }, { "version": "0", "lessThan": "6.18", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.50", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2.4", "lessThanOrEqual": "7.2.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.3", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "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" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/ab5dcde6fa96bc115b85f3621c60e39c66229a90" }, { "url": "https://git.kernel.org/stable/c/3e19172089ec81132a8a48e802b1034a744209f4" }, { "url": "https://git.kernel.org/stable/c/32d1809da31094ef76fd98dc1f1a8b55ca1295dd" } ], "title": "dm-pcache: validate geometry fields from on-disk cache_info", "x_generator": { "engine": "bippy-1.2.0" } } } }