Commit 96a3aefb authored Dec 05, 2016 by Darrick J. Wong Committed by Dave Chinner Dec 05, 2016

xfs: don't crash if reading a directory results in an unexpected hole



In xfs_dir3_data_read, we can encounter the situation where err == 0 and
*bpp == NULL if the given bno offset happens to be a hole; this leads to
a crash if we try to set the buffer type after the _da_read_buf call.
Holes can happen due to corrupt or malicious entries in the bmbt data,
so be a little more careful when we're handling buffers.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

parent 356a3225

fs/xfs/libxfs/xfs_dir2_data.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -329,7 +329,7 @@ xfs_dir3_data_read(

		err = xfs_da_read_buf(tp, dp, bno, mapped_bno, bpp,
		XFS_DATA_FORK, &xfs_dir3_data_buf_ops);
		if (!err && tp)
		if (!err && tp && *bpp)
		xfs_trans_buf_set_type(tp, *bpp, XFS_BLFT_DIR_DATA_BUF);
		return err;
		}