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authorIgnat Korchagin <ignat@cloudflare.com>2024-10-14 16:38:00 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2024-12-14 20:03:47 +0100
commitfd09880b16d33aa5a7420578e01cd79148fa9829 (patch)
tree3770dca26c24ab6829d0a47f71473d91e7f462fe
parentef18243f8ecb2592af2f4eee91dc652b972fd078 (diff)
af_packet: avoid erroring out after sock_init_data() in packet_create()
[ Upstream commit 46f2a11cb82b657fd15bab1c47821b635e03838b ] 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>
-rw-r--r--net/packet/af_packet.c12
1 files changed, 6 insertions, 6 deletions
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index a705ec214254..97774bd4b6cb 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -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;