In the Linux kernel, the following vulnerability has been resolved:
blk-cgroup: fix UAF in __blkcgrstatflush()
When multiple blkgs in the same blkcg are released concurrently, a use-after-free can occur. The race happens when one blkg's __blkcgrstatflush() removes another blkg's iostat entries via llistdelall(). 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 _blkgrelease() (RCU callback) to blkgrelease() (before callrcu). This ensures the RCU grace period waits for any concurrent flush's rcureadlock() section to complete before freeing.
{
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/63xxx/CVE-2026-63802.json",
"cna_assigner": "Linux"
}