net/smc: keep clcsock reference in smc_tcp_listen_work()

Ursula Braun · davem330 · commit 070204a34884 · 2018-04-25T14:13:41.000-04:00
The internal CLC socket should exist till the SMC-socket is released. Function tcp_listen_worker() releases the internal CLC socket of a listen socket, if an smc_close_active() is called. This function is called for the final release(), but it is called for shutdown SHUT_RDWR as well. This opens a door for protection faults, if socket calls using the internal CLC socket are called for a shutdown listen socket. With the changes of commit 3d50206 ("net/smc: simplify wait when closing listen socket") there is no need anymore to release the internal CLC socket in function tcp_listen_worker((). It is sufficient to release it in smc_release(). Fixes: 127f497 ("net/smc: release clcsock from tcp_listen_worker") Signed-off-by: Ursula Braun <ubraun@linux.ibm.com> Reported-by: syzbot+9045fc589fcd196ef522@syzkaller.appspotmail.com Reported-by: syzbot+28a2c86cf19c81d871fa@syzkaller.appspotmail.com Reported-by: syzbot+9605e6cace1b5efd4a0a@syzkaller.appspotmail.com Reported-by: syzbot+cf9012c597c8379d535c@syzkaller.appspotmail.com Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c
@@ -978,10 +978,6 @@ static void smc_tcp_listen_work(struct work_struct *work)
 	}
 
 out:
-	if (lsmc->clcsock) {
-		sock_release(lsmc->clcsock);
-		lsmc->clcsock = NULL;
-	}
 	release_sock(lsk);
 	sock_put(&lsmc->sk); /* sock_hold in smc_listen */
 }

Original file line number	Diff line number	Diff line change
`@@ -978,10 +978,6 @@ static void smc_tcp_listen_work(struct work_struct *work)`
`978`	`978`	`}`
`979`	`979`
`980`	`980`	`out:`
`981`		`- if (lsmc->clcsock) {`
`982`		`- sock_release(lsmc->clcsock);`
`983`		`- lsmc->clcsock = NULL;`
`984`		`- }`
`985`	`981`	`release_sock(lsk);`
`986`	`982`	`sock_put(&lsmc->sk); /* sock_hold in smc_listen */`
`987`	`983`	`}`