From: Darrick J. Wong <darrick.wong@oracle.com>
Date: Thu, 28 Jun 2018 20:11:57 +0000 (-0500)
Subject: xfs: xfs_alloc_get_rec should return EFSCORRUPTED for obvious bnobt corruption
X-Git-Tag: v4.18.0-rc0~24
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=3741f971f3c99d00ee9bb61dded0a1e049045c8b;p=thirdparty%2Fxfsprogs-dev.git

xfs: xfs_alloc_get_rec should return EFSCORRUPTED for obvious bnobt corruption

Source kernel commit: a37f7b127ed3dcfab3edc105482891711c1966b3

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>
Signed-off-by: Eric Sandeen <sandeen@sandeen.net>
---

diff --git a/libxfs/xfs_alloc.c b/libxfs/xfs_alloc.c
index 5205d5ce0..24db8152e 100644
--- a/libxfs/xfs_alloc.c
+++ b/libxfs/xfs_alloc.c
@@ -227,10 +227,14 @@ 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;
 }