CVE-2023-53377

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

cifs: prevent use-after-free by freeing the cfile later

In smb2_compound_op we have a possible use-after-free which can cause hard to debug problems later on.

This was revealed during stress testing with KASAN enabled kernel. Fixing it by moving the cfile free call to a few lines below, after the usage.

A use-after-free in the Linux CIFS client (smb2_compound_op) could be triggered when handling SMB2 compound operations (notably around symlink handling), leading to kernel memory corruption on the client. The bug is remotely reachable only if a client accesses a malicious or misbehaving SMB server and performs the affected operations. For the Red Hat Enterprise Linux both bug and fix introduced starting from 9.4 (so it didn't exist before 9.4 and already fixed starting from 9.4).

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.