dm-pcache: validate seg_id fields from persistent memory
In the Linux kernel, the following vulnerability has been resolved: dm-pcache: validate seg_id fields from persistent memory cache_pos_decode(), cache_key_decode() and the last-kset branches of cache_replay(), the writeback worker and the GC worker take a cache segment id from the cache device metadata and index cache->segments[] with it without checking it against cache->n_segs. That metadata is only CRC-protected with a fixed public seed, so whoever supplies the cache device on a table load (CAP_SYS_ADMIN) controls the id; an out-of-range value forms a wild pcache_cache_segment pointer that is dereferenced and written through -- an out-of-bounds read and write driven by on-disk data. Add cache_seg_id_valid() and reject an out-of-range id at each decode site, failing the operation with -EIO instead of indexing past the array. Bound the id against the initialized-segment count (cache_info.n_segs) rather than the physical device total. A forged cache_info.n_segs below seg_num otherwise leaves segments[cache_info.n_segs..seg_num) as zeroed structs whose data pointer is NULL, so a forged id in that window would still be dereferenced. A later patch guarantees cache_info.n_segs <= seg_num, and a driver-created cache sets the two equal, so valid images are unaffected.
CVE-2026-93201
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-93201
Linux
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Linux
Source reference: /containers/cna/affected/1/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "1d57628ff95b32d5cfa8d8f50e07690c161e9cf0",
"lessThan": "96d4b275281b45aacd0f0510fa8bec85d9f7dc5a",
"versionType": "git"
},
{
"status": "affected",
"version": "1d57628ff95b32d5cfa8d8f50e07690c161e9cf0",
"lessThan": "b4bf8af5e7d7db4c5e179e15017da55857761ac4",
"versionType": "git"
},
{
"status": "affected",
"version": "1d57628ff95b32d5cfa8d8f50e07690c161e9cf0",
"lessThan": "90c990a68460d7b5720e5634cf650eccdf0f4098",
"versionType": "git"
}
],
"programFiles": [
"drivers/md/dm-pcache/cache.c",
"drivers/md/dm-pcache/cache.h",
"drivers/md/dm-pcache/cache_gc.c",
"drivers/md/dm-pcache/cache_key.c",
"drivers/md/dm-pcache/cache_writeback.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "6.18"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "6.18",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.18.57",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.2.6",
"versionType": "semver",
"lessThanOrEqual": "7.2.*"
},
{
"status": "unaffected",
"version": "7.3",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"drivers/md/dm-pcache/cache.c",
"drivers/md/dm-pcache/cache.h",
"drivers/md/dm-pcache/cache_gc.c",
"drivers/md/dm-pcache/cache_key.c",
"drivers/md/dm-pcache/cache_writeback.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-93201
Source reference:
/cveMetadata/cveId
Publisher severity
high
Source reference: /containers/cna/metrics
- Event
- #37906 · Revision 1
- Added to Heist Feed
- Publisher date