Linux Ethernet Bridging - Feb 2015 - [Bridge] [PATCH net-next] bridge: add missing bridge port check for offloads

From: Roopa Prabhu <roopa at cumulusnetworks.com>

This patch fixes a missing bridge port check caught by smatch.

setlink/dellink of attributes like vlans can come for a bridge device
and there is no need to offload those today. So, this patch adds a bridge
port check. (In these cases however, the BRIDGE_SELF flags will always be set
and we may not hit a problem with the current code).

smatch complaint:

The patch 68e331c785b8: "bridge: offload bridge port attributes to
switch asic if feature flag set" from Jan 29, 2015, leads to the
following Smatch complaint:

net/bridge/br_netlink.c:552 br_setlink()
	 error: we previously assumed 'p' could be null (see line 518)

net/bridge/br_netlink.c
   517
   518		if (p && protinfo) {
                    ^
Check for NULL.

Reported-By: Dan Carpenter <dan.carpenter at oracle.com>
Signed-off-by: Roopa Prabhu <roopa at cumulusnetworks.com>
---
 net/bridge/br_netlink.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/net/bridge/br_netlink.c b/net/bridge/br_netlink.c
index b93f42c..4fbcea0 100644
--- a/net/bridge/br_netlink.c
+++ b/net/bridge/br_netlink.c
@@ -543,7 +543,7 @@ int br_setlink(struct net_device *dev, struct nlmsghdr *nlh,
u16 flags)
 				afspec, RTM_SETLINK);
 	}
 
-	if (!(flags & BRIDGE_FLAGS_SELF)) {
+	if (p && !(flags & BRIDGE_FLAGS_SELF)) {
 		/* set bridge attributes in hardware if supported
 		 */
 		ret_offload = netdev_switch_port_bridge_setlink(dev, nlh,
@@ -583,7 +583,7 @@ int br_dellink(struct net_device *dev, struct nlmsghdr *nlh,
u16 flags)
 		 */
 		br_ifinfo_notify(RTM_NEWLINK, p);
 
-	if (!(flags & BRIDGE_FLAGS_SELF)) {
+	if (p && !(flags & BRIDGE_FLAGS_SELF)) {
 		/* del bridge attributes in hardware
 		 */
 		ret_offload = netdev_switch_port_bridge_dellink(dev, nlh,
-- 
1.7.10.4

From: roopa at cumulusnetworks.com
Date: Thu,  5 Feb 2015 22:24:45 -0800
> From: Roopa Prabhu <roopa at cumulusnetworks.com>
> 
> This patch fixes a missing bridge port check caught by smatch.
> 
> setlink/dellink of attributes like vlans can come for a bridge device
> and there is no need to offload those today. So, this patch adds a bridge
> port check. (In these cases however, the BRIDGE_SELF flags will always be
set
> and we may not hit a problem with the current code).
> 
> smatch complaint:
> 
> The patch 68e331c785b8: "bridge: offload bridge port attributes to
> switch asic if feature flag set" from Jan 29, 2015, leads to the
> following Smatch complaint:
> 
> net/bridge/br_netlink.c:552 br_setlink()
> 	 error: we previously assumed 'p' could be null (see line 518)
> 
> net/bridge/br_netlink.c
>    517
>    518		if (p && protinfo) {
>                     ^
> Check for NULL.
> 
> Reported-By: Dan Carpenter <dan.carpenter at oracle.com>
> Signed-off-by: Roopa Prabhu <roopa at cumulusnetworks.com>
Applied, thanks.