linux-kernel - [PATCH v3 net-next 7/9] sunvnet: remove extra rcu_read

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Fri, 10 Feb 2017 09:38:23 -0800
From:   Shannon Nelson <shannon.nelson@...cle.com>
To:     netdev@...r.kernel.org, davem@...emloft.net
Cc:     sparclinux@...r.kernel.org, linux-kernel@...r.kernel.org,
        Shannon Nelson <shannon.nelson@...cle.com>
Subject: [PATCH v3 net-next 7/9] sunvnet: remove extra rcu_read_unlocks

The RCU read lock is grabbed first thing in sunvnet_start_xmit_common()
so it always needs to be released.  This removes the conditional release
in the dropped packet error path and removes a couple of superfluous
calls in the middle of the code.

Reported-by: Bijan Mottahedeh <bijan.mottahedeh@...cle.com>
Signed-off-by: Shannon Nelson <shannon.nelson@...cle.com>
---
 drivers/net/ethernet/sun/sunvnet_common.c |    8 ++------
 1 files changed, 2 insertions(+), 6 deletions(-)

diff --git a/drivers/net/ethernet/sun/sunvnet_common.c b/drivers/net/ethernet/sun/sunvnet_common.c
index e54bc95..64671f0 100644
--- a/drivers/net/ethernet/sun/sunvnet_common.c
+++ b/drivers/net/ethernet/sun/sunvnet_common.c
@@ -1255,10 +1255,8 @@ int sunvnet_start_xmit_common(struct sk_buff *skb, struct net_device *dev,
 
 	rcu_read_lock();
 	port = vnet_tx_port(skb, dev);
-	if (unlikely(!port)) {
-		rcu_read_unlock();
+	if (unlikely(!port))
 		goto out_dropped;
-	}
 
 	if (skb_is_gso(skb) && skb->len > port->tsolen) {
 		err = vnet_handle_offloads(port, skb, vnet_tx_port);
@@ -1283,7 +1281,6 @@ int sunvnet_start_xmit_common(struct sk_buff *skb, struct net_device *dev,
 			fl4.saddr = ip_hdr(skb)->saddr;
 
 			rt = ip_route_output_key(dev_net(dev), &fl4);
-			rcu_read_unlock();
 			if (!IS_ERR(rt)) {
 				skb_dst_set(skb, &rt->dst);
 				icmp_send(skb, ICMP_DEST_UNREACH,
@@ -1443,8 +1440,7 @@ int sunvnet_start_xmit_common(struct sk_buff *skb, struct net_device *dev,
 				jiffies + VNET_CLEAN_TIMEOUT);
 	else if (port)
 		del_timer(&port->clean_timer);
-	if (port)
-		rcu_read_unlock();
+	rcu_read_unlock();
 	if (skb)
 		dev_kfree_skb(skb);
 	vnet_free_skbs(freeskbs);
-- 
1.7.1