From: Darrick J. Wong <darrick.wong@oracle.com>
Date: Sun, 3 Jun 2018 23:10:14 +0000 (-0700)
Subject: xfs: xfs_alloc_get_rec should return EFSCORRUPTED for obvious bnobt corruption
X-Git-Tag: v4.19~795^2~26
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=a37f7b127ed3dcfab3edc105482891711c1966b3;p=platform%2Fkernel%2Flinux-rpi.git

xfs: xfs_alloc_get_rec should return EFSCORRUPTED for obvious bnobt corruption

Return -EFSCORRUPTED when the bnobt/cntbt return obviously corrupt
values, rather than letting them bounce around in the internal code.

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

diff --git a/fs/xfs/libxfs/xfs_alloc.c b/fs/xfs/libxfs/xfs_alloc.c
index dc9dd38..0214a77 100644
--- a/fs/xfs/libxfs/xfs_alloc.c
+++ b/fs/xfs/libxfs/xfs_alloc.c
@@ -231,10 +231,14 @@ xfs_alloc_get_rec(
 	int			error;
 
 	error = xfs_btree_get_rec(cur, &rec, stat);
-	if (!error && *stat == 1) {
-		*bno = be32_to_cpu(rec->alloc.ar_startblock);
-		*len = be32_to_cpu(rec->alloc.ar_blockcount);
-	}
+	if (error || !(*stat))
+		return error;
+	if (rec->alloc.ar_blockcount == 0)
+		return -EFSCORRUPTED;
+
+	*bno = be32_to_cpu(rec->alloc.ar_startblock);
+	*len = be32_to_cpu(rec->alloc.ar_blockcount);
+
 	return error;
 }