[linux-next:master 8182/13385] net/rds/tcp_listen.c:136 rds_tcp_accept_one() error: we previously assumed 'new_sock' could be null (see line 131)

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

BCC: lkp@intel.com
CC: oe-kbuild-all@lists.linux.dev
TO: Gerd Rausch <gerd.rausch@oracle.com>
CC: Jakub Kicinski <kuba@kernel.org>
CC: Jack Vogel <jack.vogel@oracle.com>
CC: Allison Henderson <allison.henderson@oracle.com>

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master
head:   e98d21c170b01ddef366f023bbfcf6b31509fa83
commit: db69e9b838c39f4fb17d0547aeb71d55a7f28061 [8182/13385] net/rds: rds_tcp_accept_one ought to not discard messages
:::::: branch date: 4 days ago
:::::: commit date: 4 months ago
config: sparc-randconfig-r073-20260508 (https://download.01.org/0day-ci/archive/20260512/202605121815.5u1tbtZK-lkp@intel.com/config)
compiler: sparc64-linux-gcc (GCC) 13.4.0
smatch: v0.5.0-9065-ge9cc34fd

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>
| Reported-by: Dan Carpenter <error27@gmail.com>
| Closes: https://lore.kernel.org/r/202605121815.5u1tbtZK-lkp@intel.com/

smatch warnings:
net/rds/tcp_listen.c:136 rds_tcp_accept_one() error: we previously assumed 'new_sock' could be null (see line 131)

vim +/new_sock +136 net/rds/tcp_listen.c

db69e9b838c39f Gerd Rausch       2026-01-21  107  
db69e9b838c39f Gerd Rausch       2026-01-21  108  int rds_tcp_accept_one(struct rds_tcp_net *rtn)
70041088e3b976 Andy Grover       2009-08-21  109  {
db69e9b838c39f Gerd Rausch       2026-01-21  110  	struct socket *listen_sock = rtn->rds_tcp_listen_sock;
70041088e3b976 Andy Grover       2009-08-21  111  	struct socket *new_sock = NULL;
70041088e3b976 Andy Grover       2009-08-21  112  	struct rds_connection *conn;
70041088e3b976 Andy Grover       2009-08-21  113  	int ret;
70041088e3b976 Andy Grover       2009-08-21  114  	struct inet_sock *inet;
bd7c5f983f3185 Sowmini Varadhan  2016-05-02  115  	struct rds_tcp_connection *rs_tcp = NULL;
bd7c5f983f3185 Sowmini Varadhan  2016-05-02  116  	int conn_state;
ea3b1ea5393087 Sowmini Varadhan  2016-06-30  117  	struct rds_conn_path *cp;
1e2b44e78eead7 Ka-Cheong Poon    2018-07-23  118  	struct in6_addr *my_addr, *peer_addr;
e65d4d96334e3f Ka-Cheong Poon    2018-07-30  119  #if !IS_ENABLED(CONFIG_IPV6)
e65d4d96334e3f Ka-Cheong Poon    2018-07-30  120  	struct in6_addr saddr, daddr;
e65d4d96334e3f Ka-Cheong Poon    2018-07-30  121  #endif
e65d4d96334e3f Ka-Cheong Poon    2018-07-30  122  	int dev_if = 0;
70041088e3b976 Andy Grover       2009-08-21  123  
db69e9b838c39f Gerd Rausch       2026-01-21  124  	if (!listen_sock) /* module unload or netns delete in progress */
37e14f4fe2991f Sowmini Varadhan  2016-05-18  125  		return -ENETUNREACH;
37e14f4fe2991f Sowmini Varadhan  2016-05-18  126  
db69e9b838c39f Gerd Rausch       2026-01-21  127  	mutex_lock(&rtn->rds_tcp_accept_lock);
db69e9b838c39f Gerd Rausch       2026-01-21  128  	new_sock = rtn->rds_tcp_accepted_sock;
db69e9b838c39f Gerd Rausch       2026-01-21  129  	rtn->rds_tcp_accepted_sock = NULL;
db69e9b838c39f Gerd Rausch       2026-01-21  130  
db69e9b838c39f Gerd Rausch       2026-01-21 @131  	if (!new_sock) {
db69e9b838c39f Gerd Rausch       2026-01-21  132  		ret = kernel_accept(listen_sock, &new_sock, O_NONBLOCK);
70041088e3b976 Andy Grover       2009-08-21  133  		if (ret)
db69e9b838c39f Gerd Rausch       2026-01-21  134  			goto out;
84eef2b2187ed7 Ka-Cheong Poon    2018-03-01  135  
480aeb9639d6a0 Christoph Hellwig 2020-05-28 @136  		rds_tcp_keepalive(new_sock);
6997fbd7a3dafa Tetsuo Handa      2022-05-05  137  		if (!rds_tcp_tune(new_sock)) {
6997fbd7a3dafa Tetsuo Handa      2022-05-05  138  			ret = -EINVAL;
6997fbd7a3dafa Tetsuo Handa      2022-05-05  139  			goto out;
6997fbd7a3dafa Tetsuo Handa      2022-05-05  140  		}
db69e9b838c39f Gerd Rausch       2026-01-21  141  	}
70041088e3b976 Andy Grover       2009-08-21  142  
70041088e3b976 Andy Grover       2009-08-21  143  	inet = inet_sk(new_sock->sk);
70041088e3b976 Andy Grover       2009-08-21  144  

:::::: The code at line 136 was first introduced by commit
:::::: 480aeb9639d6a077c611b303a22f9b1e5937d081 tcp: add tcp_sock_set_keepcnt

:::::: TO: Christoph Hellwig <hch@lst.de>
:::::: CC: David S. Miller <davem@davemloft.net>

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