Commit 897a9a03 authored by Fedor Pchelkin's avatar Fedor Pchelkin Committed by Yang Yingliang
Browse files

Bluetooth: L2CAP: handle NULL sock pointer in l2cap_sock_alloc 

mainline inclusion
from mainline-v6.14-rc1
commit 5f397409f8ee5bc82901eeaf799e1cbc4f8edcf1
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/IBPC5E
CVE: CVE-2024-58009

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=5f397409f8ee5bc82901eeaf799e1cbc4f8edcf1



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

A NULL sock pointer is passed into l2cap_sock_alloc() when it is called
from l2cap_sock_new_connection_cb() and the error handling paths should
also be aware of it.

Seemingly a more elegant solution would be to swap bt_sock_alloc() and
l2cap_chan_create() calls since they are not interdependent to that moment
but then l2cap_chan_create() adds the soon to be deallocated and still
dummy-initialized channel to the global list accessible by many L2CAP
paths. The channel would be removed from the list in short period of time
but be a bit more straight-forward here and just check for NULL instead of
changing the order of function calls.

Found by Linux Verification Center (linuxtesting.org) with SVACE static
analysis tool.

Fixes: 7c4f78cdb8e7 ("Bluetooth: L2CAP: do not leave dangling sk pointer on error in l2cap_sock_create()")
Cc: stable@vger.kernel.org
Signed-off-by: default avatarFedor Pchelkin <pchelkin@ispras.ru>
Reviewed-by: default avatarKuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: default avatarLuiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: default avatarYang Yingliang <yangyingliang@huawei.com>
parent 4942ceab

net/bluetooth/l2cap_sock.c

+2 −1
Original line number Diff line number Diff line
@@ -1864,6 +1864,7 @@ static struct sock *l2cap_sock_alloc(struct net *net, struct socket *sock, 
	chan = l2cap_chan_create();

	if (!chan) {

		sk_free(sk);

		if (sock)

			sock->sk = NULL;

		return NULL;

	}