kevin/linux
1
Fork 0
Code

Bluetooth: af_bluetooth: Fix deadlock

Browse Source 
Attemting to do sock_lock on .recvmsg may cause a deadlock as shown
bellow, so instead of using sock_sock this uses sk_receive_queue.lock
on bt_sock_ioctl to avoid the UAF:

INFO: task kworker/u9:1:121 blocked for more than 30 seconds.
      Not tainted 6.7.6-lemon #183
Workqueue: hci0 hci_rx_work
Call Trace:
 <TASK>
 __schedule+0x37d/0xa00
 schedule+0x32/0xe0
 __lock_sock+0x68/0xa0
 ? __pfx_autoremove_wake_function+0x10/0x10
 lock_sock_nested+0x43/0x50
 l2cap_sock_recv_cb+0x21/0xa0
 l2cap_recv_frame+0x55b/0x30a0
 ? psi_task_switch+0xeb/0x270
 ? finish_task_switch.isra.0+0x93/0x2a0
 hci_rx_work+0x33a/0x3f0
 process_one_work+0x13a/0x2f0
 worker_thread+0x2f0/0x410
 ? __pfx_worker_thread+0x10/0x10
 kthread+0xe0/0x110
 ? __pfx_kthread+0x10/0x10
 ret_from_fork+0x2c/0x50
 ? __pfx_kthread+0x10/0x10
 ret_from_fork_asm+0x1b/0x30
 </TASK>

Fixes: 2e07e8348e ("Bluetooth: af_bluetooth: Fix Use-After-Free in bt_sock_recvmsg")
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
This commit is contained in:
Luiz Augusto von Dentz 2024-03-01 12:58:11 -05:00
parent 0f0639b4d6
commit f7b94bdc1e
1 changed files with 3 additions and 7 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

10
net/bluetooth/af_bluetooth.c
View File

@ -309,14 +309,11 @@ int bt_sock_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
if (flags & MSG_OOB)
return -EOPNOTSUPP;
lock_sock(sk);
skb = skb_recv_datagram(sk, flags, &err);
if (!skb) {
if (sk->sk_shutdown & RCV_SHUTDOWN)
err = 0;
release_sock(sk);
return err;
}
@ -346,8 +343,6 @@ int bt_sock_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
skb_free_datagram(sk, skb);
release_sock(sk);
if (flags & MSG_TRUNC)
copied = skblen;
@ -570,10 +565,11 @@ int bt_sock_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
if (sk->sk_state == BT_LISTEN)
return -EINVAL;
lock_sock(sk);
spin_lock(&sk->sk_receive_queue.lock);
skb = skb_peek(&sk->sk_receive_queue);
amount = skb ? skb->len : 0;
release_sock(sk);
spin_unlock(&sk->sk_receive_queue.lock);
err = put_user(amount, (int __user *)arg);
break;