CVE-2023-53620

A logic flaw was found in the Linux kernel Multiple Device (software RAID) status reporting, where concurrent updates to resynchronization progress can overflow an internal difference calculation. This can cause the progress bar routine to loop excessively and trigger a soft lockup.

A local user could use this flaw to hang the system during array resynchronization, resulting in a denial of service.

status_resync() computes a difference between two fields that can change concurrently. If the subtraction wraps to a very large value, the code spends unbounded time emitting progress characters. The fix detects the inconsistent state and reports an “active” status without iterating, avoiding the long loop.

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 md_mod from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.