tipc: check link name with right length in tipc_nl_compat_link_set
commit 8c63bf9ab4be8b83bd8c34aacfd2f1d2c8901c8a upstream.
A similar issue as fixed by Patch "tipc: check bearer name with right
length in tipc_nl_compat_bearer_enable" was also found by syzbot in
tipc_nl_compat_link_set().
The length to check with should be 'TLV_GET_DATA_LEN(msg->req) -
offsetof(struct tipc_link_config, name)'.
Reported-by: syzbot+de00a87b8644a582ae79@syzkaller.appspotmail.com
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/net/tipc/netlink_compat.c b/net/tipc/netlink_compat.c
index 4838083..0cf9403 100644
--- a/net/tipc/netlink_compat.c
+++ b/net/tipc/netlink_compat.c
@@ -768,7 +768,12 @@
lc = (struct tipc_link_config *)TLV_DATA(msg->req);
- len = min_t(int, TLV_GET_DATA_LEN(msg->req), TIPC_MAX_LINK_NAME);
+ len = TLV_GET_DATA_LEN(msg->req);
+ len -= offsetof(struct tipc_link_config, name);
+ if (len <= 0)
+ return -EINVAL;
+
+ len = min_t(int, len, TIPC_MAX_LINK_NAME);
if (!string_is_valid(lc->name, len))
return -EINVAL;