net/smc: take sock lock in smc_ioctl()

SMC ioctl processing requires the sock lock to work properly in
all thinkable scenarios.
Problem has been found with RaceFuzzer and fixes:
   KASAN: null-ptr-deref Read in smc_ioctl

Reported-by: Byoungyoung Lee <lifeasageek@gmail.com>
Reported-by: syzbot+35b2c5aa76fd398b9fd4@syzkaller.appspotmail.com
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Reviewed-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Ursula Braun 2018-07-16 13:56:52 +02:00 committed by David S. Miller
parent bd598d2050
commit 1992d99882

View file

@ -1524,10 +1524,13 @@ static int smc_ioctl(struct socket *sock, unsigned int cmd,
return -EBADF; return -EBADF;
return smc->clcsock->ops->ioctl(smc->clcsock, cmd, arg); return smc->clcsock->ops->ioctl(smc->clcsock, cmd, arg);
} }
lock_sock(&smc->sk);
switch (cmd) { switch (cmd) {
case SIOCINQ: /* same as FIONREAD */ case SIOCINQ: /* same as FIONREAD */
if (smc->sk.sk_state == SMC_LISTEN) if (smc->sk.sk_state == SMC_LISTEN) {
release_sock(&smc->sk);
return -EINVAL; return -EINVAL;
}
if (smc->sk.sk_state == SMC_INIT || if (smc->sk.sk_state == SMC_INIT ||
smc->sk.sk_state == SMC_CLOSED) smc->sk.sk_state == SMC_CLOSED)
answ = 0; answ = 0;
@ -1536,8 +1539,10 @@ static int smc_ioctl(struct socket *sock, unsigned int cmd,
break; break;
case SIOCOUTQ: case SIOCOUTQ:
/* output queue size (not send + not acked) */ /* output queue size (not send + not acked) */
if (smc->sk.sk_state == SMC_LISTEN) if (smc->sk.sk_state == SMC_LISTEN) {
release_sock(&smc->sk);
return -EINVAL; return -EINVAL;
}
if (smc->sk.sk_state == SMC_INIT || if (smc->sk.sk_state == SMC_INIT ||
smc->sk.sk_state == SMC_CLOSED) smc->sk.sk_state == SMC_CLOSED)
answ = 0; answ = 0;
@ -1547,8 +1552,10 @@ static int smc_ioctl(struct socket *sock, unsigned int cmd,
break; break;
case SIOCOUTQNSD: case SIOCOUTQNSD:
/* output queue size (not send only) */ /* output queue size (not send only) */
if (smc->sk.sk_state == SMC_LISTEN) if (smc->sk.sk_state == SMC_LISTEN) {
release_sock(&smc->sk);
return -EINVAL; return -EINVAL;
}
if (smc->sk.sk_state == SMC_INIT || if (smc->sk.sk_state == SMC_INIT ||
smc->sk.sk_state == SMC_CLOSED) smc->sk.sk_state == SMC_CLOSED)
answ = 0; answ = 0;
@ -1556,8 +1563,10 @@ static int smc_ioctl(struct socket *sock, unsigned int cmd,
answ = smc_tx_prepared_sends(&smc->conn); answ = smc_tx_prepared_sends(&smc->conn);
break; break;
case SIOCATMARK: case SIOCATMARK:
if (smc->sk.sk_state == SMC_LISTEN) if (smc->sk.sk_state == SMC_LISTEN) {
release_sock(&smc->sk);
return -EINVAL; return -EINVAL;
}
if (smc->sk.sk_state == SMC_INIT || if (smc->sk.sk_state == SMC_INIT ||
smc->sk.sk_state == SMC_CLOSED) { smc->sk.sk_state == SMC_CLOSED) {
answ = 0; answ = 0;
@ -1573,8 +1582,10 @@ static int smc_ioctl(struct socket *sock, unsigned int cmd,
} }
break; break;
default: default:
release_sock(&smc->sk);
return -ENOIOCTLCMD; return -ENOIOCTLCMD;
} }
release_sock(&smc->sk);
return put_user(answ, (int __user *)arg); return put_user(answ, (int __user *)arg);
} }