btrfs: fix extent map leak in NOCOW direct I/O write
In the Linux kernel, the following vulnerability has been resolved: btrfs: fix extent map leak in NOCOW direct I/O write btrfs_dio_iomap_begin() calls btrfs_get_extent(), which returns an extent map reference that must be dropped on all exit paths. For direct writes into a NOCOW range, btrfs_get_blocks_direct_write() keeps using that extent map and asks btrfs_create_dio_extent() to allocate the ordered extent. If that fails, for example because btrfs_alloc_ordered_extent() fails, the function returns the error without dropping the input extent map. The PREALLOC path avoided this by dropping the input extent map before replacing it with the newly created one. Check the error from btrfs_create_dio_extent() before replacing the map and drop the input extent map on failure.
CVE-2026-89644
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-2026-89644
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": "5f9a8a51d8b95505d8de8b7191ae2ed8c504d4af",
"lessThan": "cb732d302245b14943a5017015fffa8e6db7a6c0",
"versionType": "git"
},
{
"status": "affected",
"version": "5f9a8a51d8b95505d8de8b7191ae2ed8c504d4af",
"lessThan": "b7c873765875645b11503f94c9bae2ca80127375",
"versionType": "git"
},
{
"status": "affected",
"version": "5f9a8a51d8b95505d8de8b7191ae2ed8c504d4af",
"lessThan": "f42efd634c0ae7ba0ce2fc5e30e291b0803b0ae2",
"versionType": "git"
},
{
"status": "affected",
"version": "5f9a8a51d8b95505d8de8b7191ae2ed8c504d4af",
"lessThan": "05a1a816eef8b3e4332620a64fc8cf45c4eb5c0d",
"versionType": "git"
},
{
"status": "affected",
"version": "5f9a8a51d8b95505d8de8b7191ae2ed8c504d4af",
"lessThan": "3f950867c307c5413d628a153ac44915bd117ffd",
"versionType": "git"
}
],
"programFiles": [
"fs/btrfs/direct-io.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "4.7"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "4.7",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.6.160",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.111",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.50",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.2.4",
"versionType": "semver",
"lessThanOrEqual": "7.2.*"
},
{
"status": "unaffected",
"version": "7.3",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"fs/btrfs/direct-io.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-89644
Source reference:
/cveMetadata/cveId
Publisher severity
No explicit severity was provided.
- Event
- #46695 · Revision 1
- Added to Heist Feed
- Publisher date