Description
In the Linux kernel, the following vulnerability has been resolved: fs/ntfs3: prevent uninitialized lcn caused by zero len syzbot reported a uninit-value in ntfs_iomap_begin [1]. Since runs was not touched yet, run_lookup_entry() immediately fails and returns false, which makes the value of "*len" 0. Simultaneously, the new value and err value are also 0, causing the logic in attr_data_get_block_locked() to jump directly to ok, ultimately resulting in *lcn being triggered before it is set [1]. In ntfs_iomap_begin(), the check for a 0 value in clen is moved forward to before updating lcn to avoid this [1]. [1] BUG: KMSAN: uninit-value in ntfs_iomap_begin+0x8c0/0x1460 fs/ntfs3/inode.c:825 ntfs_iomap_begin+0x8c0/0x1460 fs/ntfs3/inode.c:825 iomap_iter+0x9b7/0x1540 fs/iomap/iter.c:110 Local variable lcn created at: ntfs_iomap_begin+0x15d/0x1460 fs/ntfs3/inode.c:786
Product status
10d7c95af043b45a85dc738c3271bf760ff3577e (git) before 485f750cac3d8bdf5552a0e3d79ce5e3a03ece49
10d7c95af043b45a85dc738c3271bf760ff3577e (git) before e98266e823a1fa06fe6499df61aeaac2fd6f7a49
7.0
Any version before 7.0
7.0.10 (semver)
7.1 (original_commit_for_fix)
References
git.kernel.org/...c/485f750cac3d8bdf5552a0e3d79ce5e3a03ece49
git.kernel.org/...c/e98266e823a1fa06fe6499df61aeaac2fd6f7a49