From: Darrick J. Wong <darrick.wong@oracle.com>
Date: Thu, 28 Jun 2018 20:11:57 +0000 (-0500)
Subject: xfs: xfs_rtbuf_get should check the bmapi_read results
X-Git-Tag: v4.18.0-rc0~31
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=5e28c9c80acc4ef2dbf25853e4c18fec258779ce;p=thirdparty%2Fxfsprogs-dev.git

xfs: xfs_rtbuf_get should check the bmapi_read results

Source kernel commit: a03f1641c7a6d4e88c6aae0cd3d52305cdb967a0

The xfs_rtbuf_get function should check the block mapping it gets back
from bmapi_read.  If there are no mappings or the mapping isn't a real
extent, we should return -EFSCORRUPTED rather than trying to read a
garbage value.  We also require realtime bitmap blocks to be real,
written allocations.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Allison Henderson <allison.henderson@oracle.com>
Reviewed-by: Bill O'Donnell <billodo@redhat.com>
Signed-off-by: Eric Sandeen <sandeen@sandeen.net>
---

diff --git a/libxfs/xfs_rtbitmap.c b/libxfs/xfs_rtbitmap.c
index cf04ccac4..652eb4f69 100644
--- a/libxfs/xfs_rtbitmap.c
+++ b/libxfs/xfs_rtbitmap.c
@@ -85,6 +85,9 @@ xfs_rtbuf_get(
 	if (error)
 		return error;
 
+	if (nmap == 0 || !xfs_bmap_is_real_extent(&map))
+		return -EFSCORRUPTED;
+
 	ASSERT(map.br_startblock != NULLFSBLOCK);
 	error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp,
 				   XFS_FSB_TO_DADDR(mp, map.br_startblock),