Answer in brief
CVE-2026-63802 records a Unknown severity vulnerability in blk-cgroup: fix UAF in __blkcg_rstat_flush(). 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 | >=20cb1c2fb7568a6054c55defe044311397e01ddb <96e545410c4f74c89d496c1d5d9ef8d08f14368b || >=20cb1c2fb7568a6054c55defe044311397e01ddb <bbebd9425cad3573d1527441753899b926525a0f || >=20cb1c2fb7568a6054c55defe044311397e01ddb <5e5b7f2ef854936e95dceb6a2fdfefcb7152d2c6 || >=20cb1c2fb7568a6054c55defe044311397e01ddb <afebe44facc48a61761e885bbb7f0380d4a603ec || >=20cb1c2fb7568a6054c55defe044311397e01ddb <0ab5ee5a1badb58cbb2242617cb01a4972b1f2a2 || 0f6090d90f627d8c58f939067d6c6821ce1b3c68 || >=6.3.9 <6.4 | 96e545410c4f74c89d496c1d5d9ef8d08f14368b, bbebd9425cad3573d1527441753899b926525a0f, 5e5b7f2ef854936e95dceb6a2fdfefcb7152d2c6, afebe44facc48a61761e885bbb7f0380d4a603ec, 0ab5ee5a1badb58cbb2242617cb01a4972b1f2a2, 6.4 |
| Linux/Linuxgeneric | 6.4 | Not reported |
Published upstream
Jul 19, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 5, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 5, 2026
In the Linux kernel, the following vulnerability has been resolved: blk-cgroup: fix UAF in __blkcg_rstat_flush() When multiple blkgs in the same blkcg are released concurrently, a use-after-free can occur. The race happens when one blkg's __blkcg_rstat_flush() removes another blkg's iostat entries via llist_del_all(). The second blkg sees an empty list and proceeds to free itself while the first is still iterating over its entries. Move the flush from __blkg_release() (RCU callback) to blkg_release() (before call_rcu). This ensures the RCU grace period waits for any concurrent flush's rcu_read_lock() section to complete before freeing.
Quoted source text, attributed separately from HOL analysis.
Answer in brief
CVE-2026-63802 records a Unknown severity vulnerability in blk-cgroup: fix UAF in __blkcg_rstat_flush(). 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 | >=20cb1c2fb7568a6054c55defe044311397e01ddb <96e545410c4f74c89d496c1d5d9ef8d08f14368b || >=20cb1c2fb7568a6054c55defe044311397e01ddb <bbebd9425cad3573d1527441753899b926525a0f || >=20cb1c2fb7568a6054c55defe044311397e01ddb <5e5b7f2ef854936e95dceb6a2fdfefcb7152d2c6 || >=20cb1c2fb7568a6054c55defe044311397e01ddb <afebe44facc48a61761e885bbb7f0380d4a603ec || >=20cb1c2fb7568a6054c55defe044311397e01ddb <0ab5ee5a1badb58cbb2242617cb01a4972b1f2a2 || 0f6090d90f627d8c58f939067d6c6821ce1b3c68 || >=6.3.9 <6.4 | 96e545410c4f74c89d496c1d5d9ef8d08f14368b, bbebd9425cad3573d1527441753899b926525a0f, 5e5b7f2ef854936e95dceb6a2fdfefcb7152d2c6, afebe44facc48a61761e885bbb7f0380d4a603ec, 0ab5ee5a1badb58cbb2242617cb01a4972b1f2a2, 6.4 |
| Linux/Linuxgeneric | 6.4 | Not reported |
Published upstream
Jul 19, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 5, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 5, 2026
In the Linux kernel, the following vulnerability has been resolved: blk-cgroup: fix UAF in __blkcg_rstat_flush() When multiple blkgs in the same blkcg are released concurrently, a use-after-free can occur. The race happens when one blkg's __blkcg_rstat_flush() removes another blkg's iostat entries via llist_del_all(). The second blkg sees an empty list and proceeds to free itself while the first is still iterating over its entries. Move the flush from __blkg_release() (RCU callback) to blkg_release() (before call_rcu). This ensures the RCU grace period waits for any concurrent flush's rcu_read_lock() section to complete before freeing.
Quoted source text, attributed separately from HOL analysis.