mptcp: pm: add a build check for userspace_pm_dump_addr

This patch adds a build check for mptcp_userspace_pm_dump_addr() to make
sure there is enough space in 'cb->ctx' to store an address id bitmap.

Just in case info stored in 'cb->ctx' are increased later.

Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20250221-net-next-mptcp-pm-misc-cleanup-3-v1-3-2b70ab1cee79@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/net/mptcp/pm_userspace.c b/net/mptcp/pm_userspace.c
index 277cf092a87042a85623470237a8ef24d29e65e6..b69fb5b18130cb3abd08e3ef47004f599895486a 100644 (file)
--- a/net/mptcp/pm_userspace.c
+++ b/net/mptcp/pm_userspace.c
@@ -643,6 +643,8 @@ int mptcp_userspace_pm_dump_addr(struct sk_buff *msg,
        struct sock *sk;
        void *hdr;
 
+       BUILD_BUG_ON(sizeof(struct id_bitmap) > sizeof(cb->ctx));
+
        bitmap = (struct id_bitmap *)cb->ctx;
 
        msk = mptcp_userspace_pm_get_sock(info);