This is a note to let you know that I've just added the patch titled
fs/ntfs3: Fix slab-out-of-bounds read in ntfs_trim_fs
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
fs-ntfs3-fix-slab-out-of-bounds-read-in-ntfs_trim_fs.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 2ba0ac03f215b55ee446e7b2666f58988a1b86fa
Author: Abdun Nihaal <abdun.nihaal@xxxxxxxxx>
Date: Sat Oct 1 12:30:24 2022 +0530
fs/ntfs3: Fix slab-out-of-bounds read in ntfs_trim_fs
[ Upstream commit 557d19675a470bb0a98beccec38c5dc3735c20fa ]
Syzbot reports an out of bound access in ntfs_trim_fs.
The cause of this is using a loop termination condition that compares
window index (iw) with wnd->nbits instead of wnd->nwnd, due to which the
index used for wnd->free_bits exceeds the size of the array allocated.
Fix the loop condition.
Fixes: 3f3b442b5ad2 ("fs/ntfs3: Add bitmap")
Link: https://syzkaller.appspot.com/bug?extid=b892240eac461e488d51
Reported-by: syzbot+b892240eac461e488d51@xxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Abdun Nihaal <abdun.nihaal@xxxxxxxxx>
Signed-off-by: Konstantin Komarov <almaz.alexandrovich@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/fs/ntfs3/bitmap.c b/fs/ntfs3/bitmap.c
index aa184407520f..7f2055b7427a 100644
--- a/fs/ntfs3/bitmap.c
+++ b/fs/ntfs3/bitmap.c
@@ -1432,7 +1432,7 @@ int ntfs_trim_fs(struct ntfs_sb_info *sbi, struct fstrim_range *range)
down_read_nested(&wnd->rw_lock, BITMAP_MUTEX_CLUSTERS);
- for (; iw < wnd->nbits; iw++, wbit = 0) {
+ for (; iw < wnd->nwnd; iw++, wbit = 0) {
CLST lcn_wnd = iw * wbits;
struct buffer_head *bh;
