[PATCH 3/9] sctp: Check address length before reading srx_service field

[Tetsuo Handa]

KMSAN will complain if valid address length passed to connect() is shorter
than sizeof("struct sockaddr"->sa_family) bytes.

Signed-off-by: Tetsuo Handa <penguin-ker...@i-love.sakura.ne.jp>
---
 net/sctp/socket.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/net/sctp/socket.c b/net/sctp/socket.c
index 9874e60c9b0d..4583fa914e62 100644
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -4847,7 +4847,8 @@ static int sctp_connect(struct sock *sk, struct sockaddr 
*addr,
        }
 
        /* Validate addr_len before calling common connect/connectx routine. */
-       af = sctp_get_af_specific(addr->sa_family);
+       af = addr_len < offsetofend(struct sockaddr, sa_family) ? NULL :
+               sctp_get_af_specific(addr->sa_family);
        if (!af || addr_len < af->sockaddr_len) {
                err = -EINVAL;
        } else {
-- 
2.16.5