CVE-2023-52983

In the Linux kernel, the following vulnerability has been resolved:

block, bfq: fix uaf for bfqq in bic_set_bfqq()

After commit 64dc8c732f5c ("block, bfq: fix possible uaf for 'bfqq->bic'"), bic->bfqq will be accessed in bic_set_bfqq(), however, in some context bic->bfqq will be freed, and bic_set_bfqq() is called with the freed bic->bfqq.

Fix the problem by always freeing bfqq after bic_set_bfqq().

Red Hat Enterprise Linux (all versions) not affected, because the part of the source code that contains the bug not introduced yet.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

To mitigate this issue, prevent module bfq from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.