diff options
| author | Raphael Pinsonneault-Thibeault <rpthibeault@gmail.com> | 2025-10-12 16:16:34 -0400 |
|---|---|---|
| committer | Konstantin Komarov <almaz.alexandrovich@paragon-software.com> | 2025-10-17 16:45:37 +0200 |
| commit | 73e6b9dacf72a1e7a4265eacca46f8f33e0997d6 (patch) | |
| tree | d894aec2124994e952816f9350efdce403b81c46 | |
| parent | 02f312754c873efe076888a2fdca982e56617929 (diff) | |
ntfs3: fix uninit memory after failed mi_read in mi_format_new
Fix a KMSAN un-init bug found by syzkaller.
ntfs_get_bh() expects a buffer from sb_getblk(), that buffer may not be
uptodate. We do not bring the buffer uptodate before setting it as
uptodate. If the buffer were to not be uptodate, it could mean adding a
buffer with un-init data to the mi record. Attempting to load that record
will trigger KMSAN.
Avoid this by setting the buffer as uptodate, if it’s not already, by
overwriting it.
Reported-by: syzbot+7a2ba6b7b66340cff225@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=7a2ba6b7b66340cff225
Tested-by: syzbot+7a2ba6b7b66340cff225@syzkaller.appspotmail.com
Fixes: 4342306f0f0d5 ("fs/ntfs3: Add file operations and implementation")
Signed-off-by: Raphael Pinsonneault-Thibeault <rpthibeault@gmail.com>
Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
| -rw-r--r-- | fs/ntfs3/fsntfs.c | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/fs/ntfs3/fsntfs.c b/fs/ntfs3/fsntfs.c index c7a2f191254d..5ae910e9ecbd 100644 --- a/fs/ntfs3/fsntfs.c +++ b/fs/ntfs3/fsntfs.c @@ -1349,7 +1349,14 @@ int ntfs_get_bh(struct ntfs_sb_info *sbi, const struct runs_tree *run, u64 vbo, } if (buffer_locked(bh)) __wait_on_buffer(bh); - set_buffer_uptodate(bh); + + lock_buffer(bh); + if (!buffer_uptodate(bh)) + { + memset(bh->b_data, 0, blocksize); + set_buffer_uptodate(bh); + } + unlock_buffer(bh); } else { bh = ntfs_bread(sb, block); if (!bh) { |