| Message ID | 20191029114126.59907-1-ubraun@linux.ibm.com |
|---|---|
| State | Accepted |
| Delegated to: | David Miller |
| Headers | show |
| Series | [net,1/1] net/smc: fix refcounting for non-blocking connect() | expand |
From: Ursula Braun <ubraun@linux.ibm.com> Date: Tue, 29 Oct 2019 12:41:26 +0100 > 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> Applied and queued up for -stable, thank you.
diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c index cea3c36ea0da..47946f489fd4 100644 --- a/net/smc/af_smc.c +++ b/net/smc/af_smc.c @@ -707,8 +707,6 @@ static int __smc_connect(struct smc_sock *smc) 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 *sock, struct sockaddr *addr, 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;
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> --- net/smc/af_smc.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)