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Bluetooth: af_bluetooth: Fix Use-After-Free in bt_sock_recvmsg

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[ Upstream commit 2e07e8348ea454615e268222ae3fc240421be768 ]

This can cause a race with bt_sock_ioctl() because
bt_sock_recvmsg() gets the skb from sk->sk_receive_queue
and then frees it without holding lock_sock.
A use-after-free for a skb occurs with the following flow.
```
bt_sock_recvmsg() -> skb_recv_datagram() -> skb_free_datagram()
bt_sock_ioctl() -> skb_peek()
```
Add lock_sock to bt_sock_recvmsg() to fix this issue.

Cc: stable@vger.kernel.org
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Hyunwoo Kim <v4bel@theori.io>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Hyunwoo Kim 2023-12-09 05:55:18 -05:00 committed by Ksawlii
parent 9011b2c0fe
commit f4f207995f
1 changed files with 6 additions and 1 deletions
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7
net/bluetooth/af_bluetooth.c
View file

@ -263,11 +263,14 @@ int bt_sock_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
if (flags & MSG_OOB) if (flags & MSG_OOB)
return -EOPNOTSUPP; return -EOPNOTSUPP;
lock_sock(sk);
skb = skb_recv_datagram(sk, flags, noblock, &err); skb = skb_recv_datagram(sk, flags, noblock, &err);
if (!skb) { if (!skb) {
if (sk->sk_shutdown & RCV_SHUTDOWN) if (sk->sk_shutdown & RCV_SHUTDOWN)
return 0; err = 0;
release_sock(sk);
return err; return err;
} }
@ -293,6 +296,8 @@ int bt_sock_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
skb_free_datagram(sk, skb); skb_free_datagram(sk, skb);
release_sock(sk);
if (flags & MSG_TRUNC) if (flags & MSG_TRUNC)
copied = skblen; copied = skblen;