CVE-2026-72471
HighCVSS 7.1Exploitation Probability (EPSS)
Low risk24th percentile - higher than 24% of all known CVEs
Summary
In the Linux kernel, the NTFS3 filesystem has a vulnerability involving the use of an uninitialized variable lcn. When the sought VCN is not found in runs[0], run_lookup() returns false, leading to premature exit from attr_data_get_block_locked() without initializing lcn, triggering a KMSAN bug. The fix moves the clen check before the lcn check in ni_seek_data_or_hole().
Risk Assessment
Use of an uninitialized variable can lead to unpredictable behavior, system crash, or potential data security compromise.
Recommendation
Apply the kernel patch that moves the clen check before the lcn check. Update the system to a kernel version with the fix.
Original NVD description (English source)
In the Linux kernel, the following vulnerability has been resolved: fs/ntfs3: prevent potential lcn remains uninitialized The target VCN being sought was not found within runs[0], causing run_lookup() to return false. This causes run_lookup_entry() to return false, which in turn results in a len value of 0, and the new parameter passed to attr_data_get_block() is NULL. Collectively, these factors ultimately cause attr_data_get_block_locked() to exit prematurely without initializing lcn, thereby triggering [1]. To prevent [1], the clen check within ni_seek_data_or_hole() has been moved to occur before the lcn check. [1] BUG: KMSAN: uninit-value in ni_seek_data_or_hole+0x24f/0x5f0 fs/ntfs3/frecord.c:2862 ni_seek_data_or_hole+0x24f/0x5f0 fs/ntfs3/frecord.c:2862 ntfs_llseek+0x22a/0x4a0 fs/ntfs3/file.c:1530 vfs_llseek fs/read_write.c:391 [inline]