[dm-devel] [PATCH 09/14] libmultipath: check whether mp->features is NULl in, assemble_map

[lixiaokeng]

In assemble_map func, if add_feature fails and mp->features is
default value (NULL), STRDUP(mp->features) will cause a seg-fault.
In addition, f = STRDUP(mp->features) is just used for APPEND().
We can directly pass mp->features to APPEND().

Here, we firstly check whether mp->features is null.

Signed-off-by: Zhiqiang Liu <liuzhiqiang26 at huawei.com>
Signed-off-by: lixiaokeng <lixiaokeng at huawei.com>
---
 libmultipath/dmparser.c | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/libmultipath/dmparser.c b/libmultipath/dmparser.c
index 482e9d0e..12182bf5 100644
--- a/libmultipath/dmparser.c
+++ b/libmultipath/dmparser.c
@@ -65,7 +65,7 @@ assemble_map (struct multipath * mp, char * params, int len)
 	int i, j;
 	int minio;
 	int nr_priority_groups, initial_pg_nr;
-	char * p, * f;
+	char * p;
 	const char *const end = params + len;
 	char no_path_retry[] = "queue_if_no_path";
 	char retain_hwhandler[] = "retain_attached_hw_handler";
@@ -86,9 +86,12 @@ assemble_map (struct multipath * mp, char * params, int len)
 	    get_linux_version_code() < KERNEL_VERSION(4, 3, 0))
 		add_feature(&mp->features, retain_hwhandler);

-	f = STRDUP(mp->features);
+	if (!mp->features) {
+		condlog(0, "mp->features is still NULL.");
+		goto err;
+	}

-	APPEND(p, end, "%s %s %i %i", f, mp->hwhandler, nr_priority_groups,
+	APPEND(p, end, "%s %s %i %i", mp->features, mp->hwhandler, nr_priority_groups,
 	       initial_pg_nr);

 	vector_foreach_slot (mp->pg, pgp, i) {
@@ -110,12 +113,10 @@ assemble_map (struct multipath * mp, char * params, int len)
 		}
 	}

-	FREE(f);
 	condlog(4, "%s: assembled map [%s]", mp->alias, params);
 	return 0;

 err:
-	FREE(f);
 	return 1;
 }

--