From f2e58e95273ce072ca95a2afa1f274825a1e1772 Mon Sep 17 00:00:00 2001 From: Abdun Nihaal Date: Sat, 1 Oct 2022 12:30:24 +0530 Subject: [PATCH] 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@syzkaller.appspotmail.com Signed-off-by: Abdun Nihaal Signed-off-by: Konstantin Komarov Signed-off-by: Sasha Levin --- 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 e92bbd7..1930640 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; -- 2.7.4