af_packet: avoid erroring out after sock_init_data() in packet_create()

[ Upstream commit 46f2a11cb8 ]

After sock_init_data() the allocated sk object is attached to the provided
sock object. On error, packet_create() frees the sk object leaving the
dangling pointer in the sock object on return. Some other code may try
to use this pointer and cause use-after-free.

Suggested-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Ignat Korchagin <ignat@cloudflare.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20241014153808.51894-2-ignat@cloudflare.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Ignat Korchagin 2024-10-14 16:38:00 +01:00 committed by Greg Kroah-Hartman
parent ef18243f8e
commit fd09880b16

View File

@ -3421,17 +3421,17 @@ static int packet_create(struct net *net, struct socket *sock, int protocol,
if (sock->type == SOCK_PACKET)
sock->ops = &packet_ops_spkt;
po = pkt_sk(sk);
err = packet_alloc_pending(po);
if (err)
goto out_sk_free;
sock_init_data(sock, sk);
po = pkt_sk(sk);
init_completion(&po->skb_completion);
sk->sk_family = PF_PACKET;
po->num = proto;
err = packet_alloc_pending(po);
if (err)
goto out2;
packet_cached_dev_reset(po);
sk->sk_destruct = packet_sock_destruct;
@ -3463,7 +3463,7 @@ static int packet_create(struct net *net, struct socket *sock, int protocol,
sock_prot_inuse_add(net, &packet_proto, 1);
return 0;
out2:
out_sk_free:
sk_free(sk);
out:
return err;