libceph: potential NULL dereference in ceph_msg_data_create()

If kmem_cache_zalloc() returns NULL then the INIT_LIST_HEAD(&data->links);
will Oops.  The callers aren't really prepared for NULL returns so it
doesn't make a lot of difference in real life.

Fixes: 5240d9f95dfe ("libceph: replace message data pointer with list")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

1 files changed, 4 insertions, 2 deletions

diff --git a/net/ceph/messenger.c b/net/ceph/messenger.c
index 0c31035bbfee..b7cc615d42ef 100644
--- a/net/ceph/messenger.c
+++ b/net/ceph/messenger.c
@@ -3203,8 +3203,10 @@ static struct ceph_msg_data *ceph_msg_data_create(enum ceph_msg_data_type type)
                 return NULL;
 
         data = kmem_cache_zalloc(ceph_msg_data_cache, GFP_NOFS);
-        if (data)
-                data->type = type;
+        if (!data)
+                return NULL;
+
+        data->type = type;
         INIT_LIST_HEAD(&data->links);
 
         return data;