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 <martin...@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matt...@kernel.org>
---
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
--
2.43.0
