From 14d29ec5302caac945267b9586fad01ecddc700c Mon Sep 17 00:00:00 2001 From: "Matthieu Baerts (NGI0)" Date: Fri, 23 Feb 2024 21:17:56 +0100 Subject: mptcp: check the protocol in mptcp_sk() with DEBUG_NET Fuzzers and static checkers might not detect when mptcp_sk() is used with a non mptcp_sock structure. This is similar to the parent commit, where it is easy to use mptcp_sk() with a TCP sock, e.g. with a subflow sk. So a new simple check is done when CONFIG_DEBUG_NET is enabled to tell kernel devs when a non-MPTCP socket is being used as an MPTCP one. 'mptcp_sk()' macro is then defined differently: with an extra WARN to complain when an unexpected socket is being used. Reviewed-by: Mat Martineau Signed-off-by: Matthieu Baerts (NGI0) Link: https://lore.kernel.org/r/20240223-upstream-net-next-20240223-misc-improvements-v1-4-b6c8a10396bd@kernel.org Signed-off-by: Jakub Kicinski --- net/mptcp/protocol.h | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h index 026ed360bd72..051b100d9403 100644 --- a/net/mptcp/protocol.h +++ b/net/mptcp/protocol.h @@ -356,9 +356,15 @@ static inline void msk_owned_by_me(const struct mptcp_sock *msk) WARN_ON(_ptr->sk_protocol != IPPROTO_TCP); \ container_of_const(_ptr, struct tcp_sock, inet_conn.icsk_inet.sk); \ }) -#endif +#define mptcp_sk(ptr) ({ \ + typeof(ptr) _ptr = (ptr); \ + WARN_ON(_ptr->sk_protocol != IPPROTO_MPTCP); \ + container_of_const(_ptr, struct mptcp_sock, sk.icsk_inet.sk); \ +}) +#else /* !CONFIG_DEBUG_NET */ #define mptcp_sk(ptr) container_of_const(ptr, struct mptcp_sock, sk.icsk_inet.sk) +#endif /* the msk socket don't use the backlog, also account for the bulk * free memory -- cgit v1.2.3-59-g8ed1b