CVE-2023-34256

Name of the Vulnerable Software and Affected Versions Linux kernel versions prior to 6.3.3

Description The issue is related to an out-of-bounds read in the crc16 function in lib/crc16.c when called from fs/ext4/super.c. This occurs because the ext4 group desc csum function does not properly check an offset. The exploitation of this issue may allow an attacker to impact the confidentiality, integrity, and availability of protected information. Note that this issue is disputed by third parties, as the kernel is not intended to defend against attackers with the stated access.

Recommendations To resolve the issue, update the Linux kernel to version 6.3.3 or later. As a temporary workaround, consider restricting access to the vulnerable module fs/ext4/super.c to minimize the risk of exploitation. Avoid modifying the block device while it is mounted by the filesystem to reduce the potential impact of this issue.