CVE-2026-53320

In the Linux kernel, the following vulnerability has been resolved: nilfs2: reject zero bd_oblocknr in nilfs_ioctl_mark_blocks_dirty() nilfs_ioctl_mark_blocks_dirty() uses bd_oblocknr to detect dead blocks by comparing it with the current block number bd_blocknr. If they differ, the block is considered dead and skipped. However, bd_oblocknr should never be 0 since block 0 typically stores the primary superblock and is never a valid GC target block. A corrupted ioctl request with bd_oblocknr set to 0 causes the comparison to incorrectly match when the lookup returns -ENOENT and sets bd_blocknr to 0, bypassing the dead block check and calling nilfs_bmap_mark() on a non-existent block. This causes nilfs_btree_do_lookup() to return -ENOENT, triggering the WARN_ON(ret == -ENOENT). Fix this by rejecting ioctl requests with bd_oblocknr set to 0 at the beginning of each iteration. [ryusuke: slightly modified the commit message and comments for accuracy]

• linux linux kernel (>= 2.6.30 < 5.10.258) • linux linux kernel (>= 5.11 < 5.15.209) • linux linux kernel (>= 5.16 < 6.1.175) • linux linux kernel (>= 6.2 < 6.6.141) • linux linux kernel (>= 6.7 < 6.12.91) • linux linux kernel (>= 6.13 < 6.18.33) • linux linux kernel (>= 6.19 < 7.0.10)