From: Abdun Nihaal Date: Sat, 1 Oct 2022 07:00:24 +0000 (+0530) Subject: fs/ntfs3: Fix slab-out-of-bounds read in ntfs_trim_fs X-Git-Tag: v6.0.16~288 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=7e686013b7071f4c16644cfad8808e76097724c4;p=thirdparty%2Fkernel%2Fstable.git 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 --- diff --git a/fs/ntfs3/bitmap.c b/fs/ntfs3/bitmap.c index 5d44ceac855b7..087282cb130b7 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;