CVE-2023-53569

An integer overflow vulnerability was found in the Linux kernel ext2 filesystem's block size validation during mount. A local user with privileges to mount filesystems can mount a crafted ext2 image with an excessively large log_block_size value in the superblock, causing the shift operation computing the actual block size to overflow and trigger undefined behavior, which results in denial of service through kernel crash or unpredictable system behavior.

When mounting an ext2 filesystem, ext2_fill_super() fails to validate the s_log_block_size field from the superblock before using it in a shift operation. The kernel computes the actual block size as (1 << s_log_block_size). If s_log_block_size is crafted to be an extremely large value, this shift operation causes integer overflow, resulting in undefined behavior per the C specification.

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.