Answer in brief
CVE-2026-74321 records a Unknown severity vulnerability in btrfs: fix invalid pointer dereference in __btrfs_run_delayed_refs(). The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
Answer in brief
CVE-2026-74321 records a Unknown severity vulnerability in btrfs: fix invalid pointer dereference in __btrfs_run_delayed_refs(). The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=0110a4c43451533de1ea1bbdc57b5d452f9d8b25 <c372ca227e16bace86f1df1fa4ae6849e2fcfa28 || >=0110a4c43451533de1ea1bbdc57b5d452f9d8b25 <a71143590ce9764dbcb47617647592ff8b4d48bc || >=0110a4c43451533de1ea1bbdc57b5d452f9d8b25 <65770111a2d47c2b15e20b2ba92bb12198f289d4 || >=0110a4c43451533de1ea1bbdc57b5d452f9d8b25 <015dc4a1e0c2cba551d4620eba13d26d5081dc34 || >=0110a4c43451533de1ea1bbdc57b5d452f9d8b25 <ba9fa2ff5981589bb49094d3358c339b37c47f53 || >=0110a4c43451533de1ea1bbdc57b5d452f9d8b25 <3b15d02be05e74321adb1e0ae0cb4ccfba7c6cb1 || >=0110a4c43451533de1ea1bbdc57b5d452f9d8b25 <9faa6b69ad73f03c7bde53e07d75a28822dc9a1a || >=0110a4c43451533de1ea1bbdc57b5d452f9d8b25 <486f8298b6188ff11ef1f4be7f1d5d2e4d1b1fae | c372ca227e16bace86f1df1fa4ae6849e2fcfa28, a71143590ce9764dbcb47617647592ff8b4d48bc, 65770111a2d47c2b15e20b2ba92bb12198f289d4, 015dc4a1e0c2cba551d4620eba13d26d5081dc34, ba9fa2ff5981589bb49094d3358c339b37c47f53, 3b15d02be05e74321adb1e0ae0cb4ccfba7c6cb1, 9faa6b69ad73f03c7bde53e07d75a28822dc9a1a, 486f8298b6188ff11ef1f4be7f1d5d2e4d1b1fae |
| Linux/Linuxgeneric | 4.20 | Not reported |
Published upstream
Aug 15, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 15, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 15, 2026
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.
Quoted source text, attributed separately from HOL analysis.
A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=0110a4c43451533de1ea1bbdc57b5d452f9d8b25 <c372ca227e16bace86f1df1fa4ae6849e2fcfa28 || >=0110a4c43451533de1ea1bbdc57b5d452f9d8b25 <a71143590ce9764dbcb47617647592ff8b4d48bc || >=0110a4c43451533de1ea1bbdc57b5d452f9d8b25 <65770111a2d47c2b15e20b2ba92bb12198f289d4 || >=0110a4c43451533de1ea1bbdc57b5d452f9d8b25 <015dc4a1e0c2cba551d4620eba13d26d5081dc34 || >=0110a4c43451533de1ea1bbdc57b5d452f9d8b25 <ba9fa2ff5981589bb49094d3358c339b37c47f53 || >=0110a4c43451533de1ea1bbdc57b5d452f9d8b25 <3b15d02be05e74321adb1e0ae0cb4ccfba7c6cb1 || >=0110a4c43451533de1ea1bbdc57b5d452f9d8b25 <9faa6b69ad73f03c7bde53e07d75a28822dc9a1a || >=0110a4c43451533de1ea1bbdc57b5d452f9d8b25 <486f8298b6188ff11ef1f4be7f1d5d2e4d1b1fae | c372ca227e16bace86f1df1fa4ae6849e2fcfa28, a71143590ce9764dbcb47617647592ff8b4d48bc, 65770111a2d47c2b15e20b2ba92bb12198f289d4, 015dc4a1e0c2cba551d4620eba13d26d5081dc34, ba9fa2ff5981589bb49094d3358c339b37c47f53, 3b15d02be05e74321adb1e0ae0cb4ccfba7c6cb1, 9faa6b69ad73f03c7bde53e07d75a28822dc9a1a, 486f8298b6188ff11ef1f4be7f1d5d2e4d1b1fae |
| Linux/Linuxgeneric | 4.20 | Not reported |
Published upstream
Aug 15, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 15, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 15, 2026
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.
Quoted source text, attributed separately from HOL analysis.