atm: Fix Use-After-Free in do_vcc_ioctl

[ Upstream commit 24e90b9e34 ]

Because do_vcc_ioctl() accesses sk->sk_receive_queue
without holding a sk->sk_receive_queue.lock, it can
cause a race with vcc_recvmsg().
A use-after-free for skb occurs with the following flow.
```
do_vcc_ioctl() -> skb_peek()
vcc_recvmsg() -> skb_recv_datagram() -> skb_free_datagram()
```
Add sk->sk_receive_queue.lock to do_vcc_ioctl() to fix this issue.

Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Hyunwoo Kim <v4bel@theori.io>
Link: https://lore.kernel.org/r/20231209094210.GA403126@v4bel-B760M-AORUS-ELITE-AX
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Hyunwoo Kim 2023-12-09 04:42:10 -05:00 committed by Greg Kroah-Hartman
parent 3a76dcab2e
commit 2de2a6cbe1

View File

@ -73,14 +73,17 @@ static int do_vcc_ioctl(struct socket *sock, unsigned int cmd,
case SIOCINQ:
{
struct sk_buff *skb;
int amount;
if (sock->state != SS_CONNECTED) {
error = -EINVAL;
goto done;
}
spin_lock_irq(&sk->sk_receive_queue.lock);
skb = skb_peek(&sk->sk_receive_queue);
error = put_user(skb ? skb->len : 0,
(int __user *)argp) ? -EFAULT : 0;
amount = skb ? skb->len : 0;
spin_unlock_irq(&sk->sk_receive_queue.lock);
error = put_user(amount, (int __user *)argp) ? -EFAULT : 0;
goto done;
}
case ATM_SETSC: