Withdrawn by the publisher.

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]

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]

Affected: Ubuntu:16.04:LTS: linux-hwe-edge, Ubuntu:18.04:LTS: linux-aws-5.0, Ubuntu:18.04:LTS: linux-aws-5.3, Ubuntu:18.04:LTS: linux-azure, Ubuntu:18.04:LTS: linux-azure-5.3, Ubuntu:18.04:LTS: linux-azure-edge, Ubuntu:18.04:LTS: linux-gcp, Ubuntu:18.04:LTS: linux-gcp-5.3, Ubuntu:18.04:LTS: linux-gke-4.15, Ubuntu:18.04:LTS: linux-gke-5.4 and 115 more

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]

Ein Angreifer kann mehrere Schwachstellen in Linux Kernel ausnutzen, um root Rechte zu erlangen, um einen Denial of Service herbeizuführen oder einen nicht näher spezifizierten Angriff durchzuführen.