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>
---
fs/ntfs3/bitmap.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/fs/ntfs3/bitmap.c b/fs/ntfs3/bitmap.c
index 1675c9a69788..629c1ee97268 100644
--- a/fs/ntfs3/bitmap.c
+++ b/fs/ntfs3/bitmap.c
@@ -1424,7 +1424,7 @@ 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;
--
2.37.3
