netdev - [PATCH net-next-2.6] icmp: icmp_send() can avoid a dev

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-next>] [day] [month] [year] [list]

Message-ID: <4AEE6E97.5070809@gmail.com>
Date:	Mon, 02 Nov 2009 06:31:03 +0100
From:	Eric Dumazet <eric.dumazet@...il.com>
To:	"David S. Miller" <davem@...emloft.net>
CC:	Linux Netdev List <netdev@...r.kernel.org>
Subject: [PATCH net-next-2.6] icmp: icmp_send() can avoid a dev_put()

We can avoid touching device refcount in icmp_send(),
using dev_get_by_index_rcu()

Signed-off-by: Eric Dumazet <eric.dumazet@...il.com>
---

diff --git a/net/ipv4/icmp.c b/net/ipv4/icmp.c
index 84adb57..fe11f60 100644
--- a/net/ipv4/icmp.c
+++ b/net/ipv4/icmp.c
@@ -501,15 +501,16 @@ void icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info)
 	if (!(rt->rt_flags & RTCF_LOCAL)) {
 		struct net_device *dev = NULL;
 
+		rcu_read_lock();
 		if (rt->fl.iif &&
 			net->ipv4.sysctl_icmp_errors_use_inbound_ifaddr)
-			dev = dev_get_by_index(net, rt->fl.iif);
+			dev = dev_get_by_index_rcu(net, rt->fl.iif);
 
-		if (dev) {
+		if (dev)
 			saddr = inet_select_addr(dev, 0, RT_SCOPE_LINK);
-			dev_put(dev);
-		} else
+		else
 			saddr = 0;
+		rcu_read_unlock();
 	}
 
 	tos = icmp_pointers[type].error ? ((iph->tos & IPTOS_TOS_MASK) |
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html