From: Ignat Korchagin <ignat@cloudflare.com> stable inclusion from stable-v5.10.231 commit 1dc1e1db927056cb323296e2294a855cd003dfe7 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IBEANY CVE: CVE-2024-56606 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- [ 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> Signed-off-by: Zhang Changzhong <zhangchangzhong@huawei.com> --- net/packet/af_packet.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index 6278535..62d1900 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -3315,18 +3315,18 @@ 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; po->xmit = dev_queue_xmit; - err = packet_alloc_pending(po); - if (err) - goto out2; - packet_cached_dev_reset(po); sk->sk_destruct = packet_sock_destruct; @@ -3361,7 +3361,7 @@ static int packet_create(struct net *net, struct socket *sock, int protocol, preempt_enable(); return 0; -out2: +out_sk_free: sk_free(sk); out: return err; -- 2.9.5