tipc: fix variable dereference before NULL check

In commit cf6f7e1 ("tipc: dump monitor attributes"), I dereferenced a pointer before checking if its valid. This is reported by static check Smatch as: net/tipc/monitor.c:733 tipc_nl_add_monitor_peer() warn: variable dereferenced before check 'mon' (see line 731) In this commit, we check for a valid monitor before proceeding with any other operation. Fixes: cf6f7e1 ("tipc: dump monitor attributes") Reported-by: Dan Carpenter <[email protected]> Signed-off-by: Parthasarathy Bhuvaragan <[email protected]> Signed-off-by: David S. Miller <[email protected]>
TechNexion · Aug 11, 2016 · 672ca65 · 672ca65
1 parent 293fddf
commit 672ca65
Showing 1 changed file with 2 additions and 1 deletion.
diff --git a/net/tipc/monitor.c b/net/tipc/monitor.c
@@ -728,12 +728,13 @@ int tipc_nl_add_monitor_peer(struct net *net, struct tipc_nl_msg *msg,
 			     u32 bearer_id, u32 *prev_node)
 {
 	struct tipc_monitor *mon = tipc_monitor(net, bearer_id);
-	struct tipc_peer *peer = mon->self;
+	struct tipc_peer *peer;
 
 	if (!mon)
 		return -EINVAL;
 
 	read_lock_bh(&mon->lock);
+	peer = mon->self;
 	do {
 		if (*prev_node) {
 			if (peer->addr == *prev_node)