diff mbox series

[net,V2,1/1] net/smc: take sock lock in smc_ioctl()

Message ID 20180716115652.72331-1-ubraun@linux.ibm.com
State Accepted, archived
Delegated to: David Miller
Headers show
Series [net,V2,1/1] net/smc: take sock lock in smc_ioctl() | expand

Commit Message

Ursula Braun July 16, 2018, 11:56 a.m. UTC 
From: Ursula Braun <ursula.braun@linux.ibm.com>

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>
---
 net/smc/af_smc.c | 19 +++++++++++++++----
 1 file changed, 15 insertions(+), 4 deletions(-)

Comments

Stefano Brivio July 16, 2018, 1:14 p.m. UTC | #1 
On Mon, 16 Jul 2018 13:56:52 +0200
Ursula Braun <ubraun@linux.ibm.com> wrote:

> From: Ursula Braun <ursula.braun@linux.ibm.com>
> 
> 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>
David Miller July 16, 2018, 9:45 p.m. UTC | #2 
From: Ursula Braun <ubraun@linux.ibm.com>
Date: Mon, 16 Jul 2018 13:56:52 +0200

> From: Ursula Braun <ursula.braun@linux.ibm.com>
> 
> 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>

Applied and queued up for -stable.
diff mbox series

Patch

diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c
index 5334157f5065..c12a7fc18f56 100644
--- a/net/smc/af_smc.c
+++ b/net/smc/af_smc.c
@@ -1524,10 +1524,13 @@  static int smc_ioctl(struct socket *sock, unsigned int cmd,
 			return -EBADF;
 		return smc->clcsock->ops->ioctl(smc->clcsock, cmd, arg);
 	}
+	lock_sock(&smc->sk);
 	switch (cmd) {
 	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;
+		}
 		if (smc->sk.sk_state == SMC_INIT ||
 		    smc->sk.sk_state == SMC_CLOSED)
 			answ = 0;
@@ -1536,8 +1539,10 @@  static int smc_ioctl(struct socket *sock, unsigned int cmd,
 		break;
 	case SIOCOUTQ:
 		/* 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;
+		}
 		if (smc->sk.sk_state == SMC_INIT ||
 		    smc->sk.sk_state == SMC_CLOSED)
 			answ = 0;
@@ -1547,8 +1552,10 @@  static int smc_ioctl(struct socket *sock, unsigned int cmd,
 		break;
 	case SIOCOUTQNSD:
 		/* 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;
+		}
 		if (smc->sk.sk_state == SMC_INIT ||
 		    smc->sk.sk_state == SMC_CLOSED)
 			answ = 0;
@@ -1556,8 +1563,10 @@  static int smc_ioctl(struct socket *sock, unsigned int cmd,
 			answ = smc_tx_prepared_sends(&smc->conn);
 		break;
 	case SIOCATMARK:
-		if (smc->sk.sk_state == SMC_LISTEN)
+		if (smc->sk.sk_state == SMC_LISTEN) {
+			release_sock(&smc->sk);
 			return -EINVAL;
+		}
 		if (smc->sk.sk_state == SMC_INIT ||
 		    smc->sk.sk_state == SMC_CLOSED) {
 			answ = 0;
@@ -1573,8 +1582,10 @@  static int smc_ioctl(struct socket *sock, unsigned int cmd,
 		}
 		break;
 	default:
+		release_sock(&smc->sk);
 		return -ENOIOCTLCMD;
 	}
+	release_sock(&smc->sk);
 
 	return put_user(answ, (int __user *)arg);
 }