From: Jonathan Liu <net147@gmail.com>
Date: Tue, 12 Apr 2011 08:28:01 +0000 (+1000)
Subject: Monitor: avoid NULL dereference with 0.90 metadata
X-Git-Tag: mdadm-3.2.2~100
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=4019ad07013a5d8618b867f724d1c4a13c5cb05d;p=thirdparty%2Fmdadm.git

Monitor: avoid NULL dereference with 0.90 metadata

0.90 array do not report the metadata type in /proc/mdstat, so
we cannot assume that mse->metadata_version is non-NULL.

So add an appropriate check.

This adds an additional check missed by commit
eb28e119b03fd5149886ed516fa4bb006ad3602e.

Signed-off-by: NeilBrown <neilb@suse.de>
---

diff --git a/Monitor.c b/Monitor.c
index a3ea7247..55aebeba 100644
--- a/Monitor.c
+++ b/Monitor.c
@@ -577,7 +577,8 @@ static int check_array(struct state *st, struct mdstat_ent *mdstat,
 			info[i].major = info[i].minor = 0;
 	}
 
-	if (strncmp(mse->metadata_version, "external:", 9) == 0 &&
+	if (mse->metadata_version &&
+	    strncmp(mse->metadata_version, "external:", 9) == 0 &&
 	    is_subarray(mse->metadata_version+9))
 		st->parent_dev =
 			devname2devnum(mse->metadata_version+10);