CVE-2026-63802
Description
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.
How to fix
- linux linux_kernel6.4, 6.6.144, 6.12.95, 6.18.38, 7.1.3 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| linux linux_kernel | 6.3.9 ≤ v < 6.4, 6.4.1 ≤ v < 6.6.144, 6.7 ≤ v < 6.12.95, 6.13 ≤ v < 6.18.38, 6.19 ≤ v < 7.1.3, 6.4 | 6.4, 6.6.144, 6.12.95, 6.18.38, 7.1.3 |
Check your version
Choose the product and enter the version you run to see whether it falls in the affected range.
Attack Surface Management
See the assets tied to your domains, the technologies they run and known vulnerabilities in one list.