From: Kuniyuki Iwashima <kuniyu@google.com>
To: Martin KaFai Lau <martin.lau@linux.dev>,
Daniel Borkmann <daniel@iogearbox.net>,
Alexei Starovoitov <ast@kernel.org>,
Andrii Nakryiko <andrii@kernel.org>,
Eduard Zingerman <eddyz87@gmail.com>,
Kumar Kartikeya Dwivedi <memxor@gmail.com>
Cc: John Fastabend <john.fastabend@gmail.com>,
Stanislav Fomichev <sdf@fomichev.me>, Song Liu <song@kernel.org>,
Yonghong Song <yonghong.song@linux.dev>,
Jiri Olsa <jolsa@kernel.org>, Eric Dumazet <edumazet@google.com>,
Kuniyuki Iwashima <kuniyu@google.com>,
Kuniyuki Iwashima <kuni1840@gmail.com>,
bpf@vger.kernel.org, netdev@vger.kernel.org,
"Matthieu Baerts (NGI0)" <matttbe@kernel.org>
Subject: [PATCH v2 bpf 3/6] mptcp: bpf: fix type confusion in bpf_mptcp_sock_from_subflow()
Date: Mon, 4 May 2026 21:04:50 +0000 [thread overview]
Message-ID: <20260504210610.180150-4-kuniyu@google.com> (raw)
In-Reply-To: <20260504210610.180150-1-kuniyu@google.com>
From: "Matthieu Baerts (NGI0)" <matttbe@kernel.org>
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: 3bc253c2e652 ("bpf: Add bpf_skc_to_mptcp_sock_proto")
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
---
v1: https://lore.kernel.org/mptcp/20260430-mptcp-bpf-mptcp-sock-type-v1-1-d2ed5cda7da9@kernel.org/
---
net/mptcp/bpf.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/mptcp/bpf.c b/net/mptcp/bpf.c
index 8a16672b94e2..4cc16cbeb328 100644
--- a/net/mptcp/bpf.c
+++ b/net/mptcp/bpf.c
@@ -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;
--
2.54.0.545.g6539524ca2-goog
next prev parent reply other threads:[~2026-05-04 21:06 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-05-04 21:04 [PATCH v2 bpf 0/6] bpf: tcp: Fix type confusion in bpf helper functions Kuniyuki Iwashima
2026-05-04 21:04 ` [PATCH v2 bpf 1/6] bpf: tcp: Fix type confusion in bpf_tcp_sock() Kuniyuki Iwashima
2026-05-04 21:50 ` bot+bpf-ci
2026-05-04 21:53 ` Kuniyuki Iwashima
2026-05-04 21:04 ` [PATCH v2 bpf 2/6] selftest: bpf: Add test for bpf_tcp_sock() and RAW socket Kuniyuki Iwashima
2026-05-04 21:04 ` Kuniyuki Iwashima [this message]
2026-05-04 21:04 ` [PATCH v2 bpf 4/6] bpf: tcp: Fix type confusion in bpf_skc_to_tcp_sock() Kuniyuki Iwashima
2026-05-04 21:04 ` [PATCH v2 bpf 5/6] bpf: tcp: Fix type confusion in bpf_skc_to_tcp6_sock() Kuniyuki Iwashima
2026-05-04 21:04 ` [PATCH v2 bpf 6/6] bpf: tcp: Fix type confusion in sol_tcp_sockopt() Kuniyuki Iwashima
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