Commit 3945c799 authored by Ignat Korchagin's avatar Ignat Korchagin Committed by Jakub Kicinski
Browse files

Bluetooth: RFCOMM: avoid leaving dangling sk pointer in rfcomm_sock_alloc() 



bt_sock_alloc() attaches allocated sk object to the provided sock object.
If rfcomm_dlc_alloc() fails, we release the sk object, but leave the
dangling pointer in the sock object, which may cause use-after-free.

Fix this by swapping calls to bt_sock_alloc() and rfcomm_dlc_alloc().

Signed-off-by: default avatarIgnat Korchagin <ignat@cloudflare.com>
Reviewed-by: default avatarKuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: default avatarEric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20241014153808.51894-4-ignat@cloudflare.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 7c4f78cd

net/bluetooth/rfcomm/sock.c

+5 −5
Original line number Diff line number Diff line
@@ -274,13 +274,13 @@ static struct sock *rfcomm_sock_alloc(struct net *net, struct socket *sock, 
	struct rfcomm_dlc *d;

	struct sock *sk;



	sk = bt_sock_alloc(net, sock, &rfcomm_proto, proto, prio, kern);

	if (!sk)

	d = rfcomm_dlc_alloc(prio);

	if (!d)

		return NULL;



	d = rfcomm_dlc_alloc(prio);

	if (!d) {

		sk_free(sk);

	sk = bt_sock_alloc(net, sock, &rfcomm_proto, proto, prio, kern);

	if (!sk) {

		rfcomm_dlc_free(d);

		return NULL;

	}