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

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

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>