Re: [PATCH net v2 6/6] tipc: fix NULL pointer dereference in named_distribute()

[kernel test robot <lkp@intel.com>]

Hi Tung,

kernel test robot noticed the following build warnings:

[auto build test WARNING on net/main]

url:    https://github.com/intel-lab-lkp/linux/commits/Tung-Nguyen/tipc-fix-memory-leak-in-tipc_node_xmit/20261102-104027
base:   net/main
patch link:    https://lore.kernel.org/r/20261102034207.10639-7-tung.quang.nguyen%40est.tech
patch subject: [PATCH net v2 6/6] tipc: fix NULL pointer dereference in named_distribute()
config: sparc64-randconfig-1001-20261102 (https://download.01.org/0day-ci/archive/20261102/202611022356.UddfVq4D-lkp@intel.com/config)
compiler: clang version 20.1.8 (https://github.com/llvm/llvm-project 87f0227cb60147a26a1eeb4fb06e3b505e9c7261)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20261102/202611022356.UddfVq4D-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202611022356.UddfVq4D-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> net/tipc/net.c:147:6: warning: variable 'p' is used uninitialized whenever 'if' condition is false [-Wsometimes-uninitialized]
     147 |         if (!tn->nt_self_node_exist)
         |             ^~~~~~~~~~~~~~~~~~~~~~~
   net/tipc/net.c:150:6: note: uninitialized use occurs here
     150 |         if (p || err == -EEXIST)
         |             ^
   net/tipc/net.c:147:2: note: remove the 'if' if its condition is always true
     147 |         if (!tn->nt_self_node_exist)
         |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
     148 |                 p = tipc_nametbl_insert(net, &ua, &sk, addr, &skb, &err);
   net/tipc/net.c:132:23: note: initialize the variable 'p' to silence this warning
     132 |         struct publication *p;
         |                              ^
         |                               = NULL
   1 warning generated.


vim +147 net/tipc/net.c

   125	
   126	static void tipc_net_finalize(struct net *net, u32 addr)
   127	{
   128		struct name_table *nt = tipc_name_table(net);
   129		struct tipc_socket_addr sk = {0, addr};
   130		struct tipc_net *tn = tipc_net(net);
   131		struct sk_buff *skb = NULL;
   132		struct publication *p;
   133		struct tipc_uaddr ua;
   134		u32 rc_dests;
   135		int err = 0;
   136	
   137		tipc_uaddr(&ua, TIPC_SERVICE_RANGE, TIPC_CLUSTER_SCOPE,
   138			   TIPC_NODE_STATE, addr, addr);
   139	
   140		if (cmpxchg(&tn->node_addr, 0, addr))
   141			return;
   142		tipc_set_node_addr(net, addr);
   143		tipc_named_reinit(net);
   144		tipc_sk_reinit(net);
   145		tipc_mon_reinit_self(net);
   146		spin_lock_bh(&tn->nametbl_lock);
 > 147		if (!tn->nt_self_node_exist)
   148			p = tipc_nametbl_insert(net, &ua, &sk, addr, &skb, &err);
   149	
   150		if (p || err == -EEXIST)
   151			tn->nt_self_node_exist = true;
   152		rc_dests = nt->rc_dests;
   153		spin_unlock_bh(&tn->nametbl_lock);
   154	
   155		if (skb)
   156			tipc_node_broadcast(net, skb, rc_dests);
   157	}
   158	

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