Overview
About vulnerability
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]
Details
- Affected product:
- Debian 10 ELS
- Affected packages:
- linux @ 4.19.0