diff options
| author | Hyunwoo Kim | 2023-12-12 23:10:56 -0500 |
|---|---|---|
| committer | Greg Kroah-Hartman | 2023-12-20 17:00:19 +0100 |
| commit | 1646b2929d5efc3861139ba58556b0f149c848f6 (patch) | |
| tree | 7ce1d93769a6cfc7dea547fd2ec801ce26961b95 /net | |
| parent | d835299dde3e668cb853539901324858845b4978 (diff) | |
appletalk: Fix Use-After-Free in atalk_ioctl
[ Upstream commit 189ff16722ee36ced4d2a2469d4ab65a8fee4198 ]
Because atalk_ioctl() accesses sk->sk_receive_queue
without holding a sk->sk_receive_queue.lock, it can
cause a race with atalk_recvmsg().
A use-after-free for skb occurs with the following flow.
```
atalk_ioctl() -> skb_peek()
atalk_recvmsg() -> skb_recv_datagram() -> skb_free_datagram()
```
Add sk->sk_receive_queue.lock to atalk_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/20231213041056.GA519680@v4bel-B760M-AORUS-ELITE-AX
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'net')
| -rw-r--r-- | net/appletalk/ddp.c | 9 |
1 files changed, 4 insertions, 5 deletions
diff --git a/net/appletalk/ddp.c b/net/appletalk/ddp.c index a06f4d4a6f47..f67f14db1633 100644 --- a/net/appletalk/ddp.c +++ b/net/appletalk/ddp.c @@ -1811,15 +1811,14 @@ static int atalk_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg) break; } case TIOCINQ: { - /* - * These two are safe on a single CPU system as only - * user tasks fiddle here - */ - struct sk_buff *skb = skb_peek(&sk->sk_receive_queue); + struct sk_buff *skb; long amount = 0; + spin_lock_irq(&sk->sk_receive_queue.lock); + skb = skb_peek(&sk->sk_receive_queue); if (skb) amount = skb->len - sizeof(struct ddpehdr); + spin_unlock_irq(&sk->sk_receive_queue.lock); rc = put_user(amount, (int __user *)argp); break; } |