btrfs: fix invalid pointer dereference in __btrfs_run_delayed_refs()
In the Linux kernel, the following vulnerability has been resolved: btrfs: fix invalid pointer dereference in __btrfs_run_delayed_refs() In the beginning of the loop, we try to obtain a locked delayed ref head, if 'locked_ref' is currently NULL, by calling btrfs_select_ref_head(), which can return an error pointer. If the error pointer is -EAGAIN we do a continue and go back to the beginning of the loop, which will not try again to call btrfs_select_ref_head() since 'locked_ref' is no longer NULL but it's ERR_PTR(-EAGAIN), and then we do: spin_lock(&locked_ref->lock); against a ERR_PTR(-EAGAIN) value, generating an invalid pointer dereference. Fix this by ensuring that 'locked_ref' is set to NULL when btrfs_select_ref_head() returns ERR_PTR(-EAGAIN) and incrementing 'count' as well, to prevent infinite looping. We do this by doing a goto to the bottom of the loop that already sets 'locked_ref' to NULL and does a cond_resched(), with an increment to 'count' right before the goto. These measures were in place before the refactoring in commit 0110a4c43451 ("btrfs: refactor __btrfs_run_delayed_refs loop") but were unintentionally lost afterwards.
CVE-2026-74321
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-2026-74321
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": "0110a4c43451533de1ea1bbdc57b5d452f9d8b25",
"lessThan": "c372ca227e16bace86f1df1fa4ae6849e2fcfa28",
"versionType": "git"
},
{
"status": "affected",
"version": "0110a4c43451533de1ea1bbdc57b5d452f9d8b25",
"lessThan": "a71143590ce9764dbcb47617647592ff8b4d48bc",
"versionType": "git"
},
{
"status": "affected",
"version": "0110a4c43451533de1ea1bbdc57b5d452f9d8b25",
"lessThan": "65770111a2d47c2b15e20b2ba92bb12198f289d4",
"versionType": "git"
},
{
"status": "affected",
"version": "0110a4c43451533de1ea1bbdc57b5d452f9d8b25",
"lessThan": "015dc4a1e0c2cba551d4620eba13d26d5081dc34",
"versionType": "git"
},
{
"status": "affected",
"version": "0110a4c43451533de1ea1bbdc57b5d452f9d8b25",
"lessThan": "ba9fa2ff5981589bb49094d3358c339b37c47f53",
"versionType": "git"
},
{
"status": "affected",
"version": "0110a4c43451533de1ea1bbdc57b5d452f9d8b25",
"lessThan": "3b15d02be05e74321adb1e0ae0cb4ccfba7c6cb1",
"versionType": "git"
},
{
"status": "affected",
"version": "0110a4c43451533de1ea1bbdc57b5d452f9d8b25",
"lessThan": "9faa6b69ad73f03c7bde53e07d75a28822dc9a1a",
"versionType": "git"
},
{
"status": "affected",
"version": "0110a4c43451533de1ea1bbdc57b5d452f9d8b25",
"lessThan": "486f8298b6188ff11ef1f4be7f1d5d2e4d1b1fae",
"versionType": "git"
}
],
"programFiles": [
"fs/btrfs/extent-tree.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "4.20"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "4.20",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "5.10.261",
"versionType": "semver",
"lessThanOrEqual": "5.10.*"
},
{
"status": "unaffected",
"version": "5.15.212",
"versionType": "semver",
"lessThanOrEqual": "5.15.*"
},
{
"status": "unaffected",
"version": "6.1.178",
"versionType": "semver",
"lessThanOrEqual": "6.1.*"
},
{
"status": "unaffected",
"version": "6.6.145",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.97",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.40",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.1.5",
"versionType": "semver",
"lessThanOrEqual": "7.1.*"
},
{
"status": "unaffected",
"version": "7.2",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"fs/btrfs/extent-tree.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-74321
Source reference:
/cveMetadata/cveId
Publisher severity
high
Source reference: /containers/cna/metrics
- Event
- #33097 · Revision 1
- Added to Heist Feed
- Publisher date