From 672ca65d9aa8578f382784fe73578cd499664828 Mon Sep 17 00:00:00 2001 From: Parthasarathy Bhuvaragan Date: Wed, 10 Aug 2016 14:07:34 +0200 Subject: [PATCH] tipc: fix variable dereference before NULL check In commit cf6f7e1d5109 ("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: cf6f7e1d5109 ("tipc: dump monitor attributes") Reported-by: Dan Carpenter Signed-off-by: Parthasarathy Bhuvaragan Signed-off-by: David S. Miller --- net/tipc/monitor.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/net/tipc/monitor.c b/net/tipc/monitor.c index b62caa1c770c..ed97a5876ebe 100644 --- 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) -- 2.20.1