tipc: Fix skb_under_panic when configuring TIPC without privileges
This patch prevents a TIPC configuration command requiring network
administrator privileges from triggering an skbuff underrun if it
is issued by a process lacking those privileges. The revised error
handling code avoids the use of a potentially uninitialized global
variable by transforming the unauthorized command into a new command,
then following the standard command processing path to generate the
required error message.
Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/tipc/netlink.c b/net/tipc/netlink.c
index 6a7f7b4..c387217 100644
--- a/net/tipc/netlink.c
+++ b/net/tipc/netlink.c
@@ -2,7 +2,7 @@
* net/tipc/netlink.c: TIPC configuration handling
*
* Copyright (c) 2005-2006, Ericsson AB
- * Copyright (c) 2005, Wind River Systems
+ * Copyright (c) 2005-2007, Wind River Systems
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
@@ -45,15 +45,17 @@
struct nlmsghdr *req_nlh = info->nlhdr;
struct tipc_genlmsghdr *req_userhdr = info->userhdr;
int hdr_space = NLMSG_SPACE(GENL_HDRLEN + TIPC_GENL_HDRLEN);
+ u16 cmd;
if ((req_userhdr->cmd & 0xC000) && (!capable(CAP_NET_ADMIN)))
- rep_buf = tipc_cfg_reply_error_string(TIPC_CFG_NOT_NET_ADMIN);
+ cmd = TIPC_CMD_NOT_NET_ADMIN;
else
- rep_buf = tipc_cfg_do_cmd(req_userhdr->dest,
- req_userhdr->cmd,
- NLMSG_DATA(req_nlh) + GENL_HDRLEN + TIPC_GENL_HDRLEN,
- NLMSG_PAYLOAD(req_nlh, GENL_HDRLEN + TIPC_GENL_HDRLEN),
- hdr_space);
+ cmd = req_userhdr->cmd;
+
+ rep_buf = tipc_cfg_do_cmd(req_userhdr->dest, cmd,
+ NLMSG_DATA(req_nlh) + GENL_HDRLEN + TIPC_GENL_HDRLEN,
+ NLMSG_PAYLOAD(req_nlh, GENL_HDRLEN + TIPC_GENL_HDRLEN),
+ hdr_space);
if (rep_buf) {
skb_push(rep_buf, hdr_space);
