mptcp: Align mptcp_inet6_sk with other protocols

heatd · intel-lab-lkp · commit 47be5bad7977 · 2025-04-30T23:47:50.000+08:00
Ever since commit f5f80e3 ("ipv6: remove hard coded limitation on ipv6_pinfo") that protocols stopped using the old "obj_size - sizeof(struct ipv6_pinfo)" way of grabbing ipv6_pinfo, that severely restricted struct layout and caused fun, hard to see issues. However, mptcp_inet6_sk wasn't fixed (unlike tcp_inet6_sk). Do so. The non-cloned sockets already do the right thing using ipv6_pinfo_offset + the generic IPv6 code. Signed-off-by: Pedro Falcato <pfalcato@suse.de>
diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
@@ -3142,9 +3142,9 @@ static int mptcp_disconnect(struct sock *sk, int flags)
 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
 static struct ipv6_pinfo *mptcp_inet6_sk(const struct sock *sk)
 {
-	unsigned int offset = sizeof(struct mptcp6_sock) - sizeof(struct ipv6_pinfo);
+	struct mptcp6_sock *msk6 = container_of(mptcp_sk(sk), struct mptcp6_sock, msk);
 
-	return (struct ipv6_pinfo *)(((u8 *)sk) + offset);
+	return &msk6->np;
 }
 
 static void mptcp_copy_ip6_options(struct sock *newsk, const struct sock *sk)

Original file line number	Diff line number	Diff line change
`@@ -3142,9 +3142,9 @@ static int mptcp_disconnect(struct sock *sk, int flags)`
`3142`	`3142`	`#if IS_ENABLED(CONFIG_MPTCP_IPV6)`
`3143`	`3143`	`static struct ipv6_pinfo mptcp_inet6_sk(const struct sock sk)`
`3144`	`3144`	`{`
`3145`		`- unsigned int offset = sizeof(struct mptcp6_sock) - sizeof(struct ipv6_pinfo);`
	`3145`	`+ struct mptcp6_sock *msk6 = container_of(mptcp_sk(sk), struct mptcp6_sock, msk);`
`3146`	`3146`
`3147`		`- return (struct ipv6_pinfo )(((u8 )sk) + offset);`
	`3147`	`+ return &msk6->np;`
`3148`	`3148`	`}`
`3149`	`3149`
`3150`	`3150`	`static void mptcp_copy_ip6_options(struct sock newsk, const struct sock sk)`