diff options
| author | Hyunwoo Kim <v4bel@theori.io> | 2023-12-09 04:42:10 -0500 |
|---|---|---|
| committer | Paolo Abeni <pabeni@redhat.com> | 2023-12-12 13:14:08 +0100 |
| commit | 24e90b9e34f9e039f56b5f25f6e6eb92cdd8f4b3 (patch) | |
| tree | 8d978d27ee13819541f7e98293c33f0f792c38b3 /net/atm | |
| parent | e307b5a845c5951dabafc48d00b6424ee64716c4 (diff) | |
atm: Fix Use-After-Free in do_vcc_ioctl
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: 1da177e4c3f4 ("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>
Diffstat (limited to 'net/atm')
| -rw-r--r-- | net/atm/ioctl.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/net/atm/ioctl.c b/net/atm/ioctl.c index 838ebf0cabbf..f81f8d56f5c0 100644 --- a/net/atm/ioctl.c +++ b/net/atm/ioctl.c @@ -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: |