[PATCH net] tipc: Dont send random pad bytes in RESET/ACTIVATE messages

[David Laight <david.laight.linux@gmail.com>]

The interface name is passed in a fixed length (TIPC_MAX_IF_NAME) buffer.
Replace the strcpy(data, l->if_name) with memcpy() so that the
pad bytes are actually written (l->if_name[] is zero padded)
rather than sending random bytes from the skb to the remote system.

Replace two other strcpy() with strscpy().

Fixes: e74a386d70c7 ("tipc: remove pre-allocated message header in link struct")
Signed-off-by: David Laight <david.laight.linux@gmail.com>
---
 net/tipc/link.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/net/tipc/link.c b/net/tipc/link.c
index 49dfc098d89b..6427c69f8929 100644
--- a/net/tipc/link.c
+++ b/net/tipc/link.c
@@ -504,7 +504,7 @@ bool tipc_link_create(struct net *net, char *if_name, int bearer_id,
 	snprintf(l->name, sizeof(l->name), "%s:%s-%s:unknown",
 		 self_str, if_name, peer_str);
 
-	strcpy(l->if_name, if_name);
+	strscpy(l->if_name, if_name);
 	l->addr = peer;
 	l->peer_caps = peer_caps;
 	l->net = net;
@@ -574,7 +574,7 @@ bool tipc_link_bc_create(struct net *net, u32 ownnode, u32 peer, u8 *peer_id,
 		snprintf(l->name, sizeof(l->name), "%s:%s", tipc_bclink_name,
 			 peer_str);
 	} else {
-		strcpy(l->name, tipc_bclink_name);
+		strscpy(l->name, tipc_bclink_name);
 	}
 	trace_tipc_link_reset(l, TIPC_DUMP_ALL, "bclink created!");
 	tipc_link_reset(l);
@@ -1898,7 +1898,7 @@ static void tipc_link_build_proto_msg(struct tipc_link *l, int mtyp, bool probe,
 			msg_set_dest_session(hdr, l->peer_session);
 		}
 		msg_set_max_pkt(hdr, l->advertised_mtu);
-		strcpy(data, l->if_name);
+		memcpy(data, l->if_name, TIPC_MAX_IF_NAME);
 		msg_set_size(hdr, INT_H_SIZE + TIPC_MAX_IF_NAME);
 		skb_trim(skb, INT_H_SIZE + TIPC_MAX_IF_NAME);
 	}
-- 
2.39.5