tipc: fix an infoleak in tipc_nl_compat_link_dump

commit 5d2be1422e02ccd697ccfcd45c85b4a26e6178e2 upstream.

link_info.str is a char array of size 60. Memory after the NULL
byte is not initialized. Sending the whole object out can cause
a leak.

Signed-off-by: Kangjie Lu <kjlu@gatech.edu>
Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 3.2: the unpadded strcpy() is in tipc_node_get_links()
 and no nlattr is involved, so use strncpy()]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/net/tipc/node.c b/net/tipc/node.c
index 27b4bb0..915bc6b 100644 (file)
--- a/net/tipc/node.c
+++ b/net/tipc/node.c
@@ -485,7 +485,8 @@ struct sk_buff *tipc_node_get_links(const void *req_tlv_area, int req_tlv_space)
                                continue;
                        link_info.dest = htonl(n_ptr->addr);
                        link_info.up = htonl(tipc_link_is_up(n_ptr->links[i]));
-                       strcpy(link_info.str, n_ptr->links[i]->name);
+                       strncpy(link_info.str, n_ptr->links[i]->name,
+                               sizeof(link_info.str));
                        tipc_cfg_append_tlv(buf, TIPC_TLV_LINK_INFO,
                                            &link_info, sizeof(link_info));
                }