CVE-2023-54264

A NULL pointer dereference vulnerability was found in the Linux kernel's System V filesystem (sysv). The code fails to check if sb_getblk() returns NULL before attempting to take a lock on the returned buffer head. When sb_getblk() fails and returns NULL, the subsequent lock operation dereferences the NULL pointer, causing a kernel crash.

This flaw affects systems mounting System V (sysv) filesystems. The NULL pointer dereference occurs when the kernel fails to allocate a buffer block during filesystem operations. While sysv is a legacy filesystem format rarely used in modern systems, mounting a crafted or corrupted sysv filesystem image could trigger this crash.

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 the sysv module from being loaded. See https://access.redhat.com/solutions/41278 for instructions.