[PATCH 4.9 194/206] xfs: complain if we dont get nextents bmap records

[Greg Kroah-Hartman]

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------


From: "Darrick J. Wong" <darrick.wong@xxxxxxxxxx>

commit 356a3225222e5bc4df88aef3419fb6424f18ab69 upstream.

When reading into memory all extents of a btree-format inode fork,
complain if the number of extents we find is not the same as the number
of extents reported in the inode core.  This is needed to stop an IO
action from accessing the garbage areas of the in-core fork.

[dchinner: removed redundant assert]

Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
Reviewed-by: Dave Chinner <dchinner@xxxxxxxxxx>
Signed-off-by: Dave Chinner <david@xxxxxxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 fs/xfs/libxfs/xfs_bmap.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

--- a/fs/xfs/libxfs/xfs_bmap.c
+++ b/fs/xfs/libxfs/xfs_bmap.c
@@ -1377,8 +1377,9 @@ xfs_bmap_read_extents(
 			return error;
 		block = XFS_BUF_TO_BLOCK(bp);
 	}
+	if (i != XFS_IFORK_NEXTENTS(ip, whichfork))
+		return -EFSCORRUPTED;
 	ASSERT(i == xfs_iext_count(ifp));
-	ASSERT(i == XFS_IFORK_NEXTENTS(ip, whichfork));
 	XFS_BMAP_TRACE_EXLIST(ip, i, whichfork);
 	return 0;
 error0: