Commit 61711948 authored May 22, 2024 by Luiz Augusto von Dentz Committed by Li Huafei May 21, 2024

Bluetooth: af_bluetooth: Fix deadlock

mainline inclusion
from mainline-v6.9-rc1
commit f7b94bdc1ec107c92262716b073b3e816d4784fb
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/I9HK0R
CVE: CVE-2024-26886

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=f7b94bdc1ec107c92262716b073b3e816d4784fb



--------------------------------

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: 2e07e8348ea4 ("Bluetooth: af_bluetooth: Fix Use-After-Free in bt_sock_recvmsg")
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Conflicts:
	net/bluetooth/af_bluetooth.c
[ The conflict occurred because commit f4b41f06 ("net: remove
noblock parameter from skb_recv_datagram()") and b8ddc3b1
("Bluetooth: fix indentation and alignment reported by checkpatch") were
not merged. ]
Signed-off-by: Li Huafei <lihuafei1@huawei.com>

parent 5af85baa

net/bluetooth/af_bluetooth.c

+3 −7

Original line number	Diff line number	Diff line
		@@ -263,14 +263,11 @@ 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, noblock, &err);
		if (!skb) {
		if (sk->sk_shutdown & RCV_SHUTDOWN)
		err = 0;

		release_sock(sk);
		return err;
		}

		@@ -293,8 +290,6 @@ 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;

		@@ -519,10 +514,11 @@ 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;