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: Ignat Korchagin <ignat@cloudflare.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20241014153808.51894-4-ignat@cloudflare.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Ignat Korchagin 2024-10-14 16:38:02 +01:00 committed by Jakub Kicinski
parent 7c4f78cdb8
commit 3945c799f1

View File

@ -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;
}