From: Ursula Braun ubraun@linux.ibm.com
[ Upstream commit 301428ea3708188dc4a243e6e6b46c03b46a0fbc ]
If a nonblocking socket is immediately closed after connect(), the connect worker may not have started. This results in a refcount problem, since sock_hold() is called from the connect worker. This patch moves the sock_hold in front of the connect worker scheduling.
Reported-by: syzbot+4c063e6dea39e4b79f29@syzkaller.appspotmail.com Fixes: 50717a37db03 ("net/smc: nonblocking connect rework") Reviewed-by: Karsten Graul kgraul@linux.ibm.com Signed-off-by: Ursula Braun ubraun@linux.ibm.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/smc/af_smc.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
--- a/net/smc/af_smc.c +++ b/net/smc/af_smc.c @@ -707,8 +707,6 @@ static int __smc_connect(struct smc_sock int smc_type; int rc = 0;
- sock_hold(&smc->sk); /* sock put in passive closing */ - if (smc->use_fallback) return smc_connect_fallback(smc, smc->fallback_rsn);
@@ -853,6 +851,8 @@ static int smc_connect(struct socket *so rc = kernel_connect(smc->clcsock, addr, alen, flags); if (rc && rc != -EINPROGRESS) goto out; + + sock_hold(&smc->sk); /* sock put in passive closing */ if (flags & O_NONBLOCK) { if (schedule_work(&smc->connect_work)) smc->connect_nonblock = 1;