Commit 7995b216 authored by Matthieu Baerts (NGI0)'s avatar Matthieu Baerts (NGI0) Committed by Martin KaFai Lau
Browse files

mptcp: bpf: Fix type confusion in bpf_mptcp_sock_from_subflow() 



bpf_mptcp_sock_from_subflow() only checks if sk->sk_protocol is
IPPROTO_TCP, but RAW socket can bypass it:

  socket(AF_INET, SOCK_RAW, IPPROTO_TCP)

In this case, it would NOT be valid to call sk_is_mptcp() which will
assume sk is a pointer to a struct tcp_sock, and wrongly checks for:
tcp_sk(sk)->is_mptcp.

Fixes: 3bc253c2 ("bpf: Add bpf_skc_to_mptcp_sock_proto")
Signed-off-by: default avatarMatthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: default avatarKuniyuki Iwashima <kuniyu@google.com>
Signed-off-by: default avatarMartin KaFai Lau <martin.lau@kernel.org>
Reviewed-by: default avatarKuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20260504210610.180150-4-kuniyu@google.com
parent d73549b8

net/mptcp/bpf.c

+1 −1
Original line number Diff line number Diff line
@@ -14,7 +14,7 @@ 


struct mptcp_sock *bpf_mptcp_sock_from_subflow(struct sock *sk)

{

	if (sk && sk_fullsock(sk) && sk->sk_protocol == IPPROTO_TCP && sk_is_mptcp(sk))

	if (sk && sk_fullsock(sk) && sk_is_tcp(sk) && sk_is_mptcp(sk))

		return mptcp_sk(mptcp_subflow_ctx(sk)->conn);



	return NULL;