CVE-2026-53320

Name of the Vulnerable Software and Affected Versions Linux kernel (affected versions not specified)

Description An issue exists in the nilfs2 file system where the nilfs ioctl mark blocks dirty() function fails to validate the bd oblocknr variable. The function uses bd oblocknr to identify dead blocks by comparing it to the current block number bd blocknr. Because block 0 is reserved for the primary superblock and is not a valid garbage collection target, bd oblocknr should never be 0. A corrupted ioctl request setting bd oblocknr to 0 can cause an incorrect match when a lookup returns -ENOENT and sets bd blocknr to 0. This bypasses the dead block check and leads to the nilfs bmap mark() function being called on a non-existent block, which subsequently causes nilfs btree do lookup() to return -ENOENT and trigger a system warning.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.