This is a note to let you know that I've just added the patch titled ipv4: do not abuse GFP_ATOMIC in inet_netconf_notify_devconf() to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: ipv4-do-not-abuse-gfp_atomic-in-inet_netconf_notify_devconf.patch and it can be found in the queue-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From fa17806cde76fb1087532f07e72aa757a30e0500 Mon Sep 17 00:00:00 2001 From: Eric Dumazet <edumazet@xxxxxxxxxx> Date: Fri, 8 Jul 2016 05:18:24 +0200 Subject: ipv4: do not abuse GFP_ATOMIC in inet_netconf_notify_devconf() From: Eric Dumazet <edumazet@xxxxxxxxxx> commit fa17806cde76fb1087532f07e72aa757a30e0500 upstream. inet_forward_change() runs with RTNL held. We are allowed to sleep if required. If we use __in_dev_get_rtnl() instead of __in_dev_get_rcu(), we no longer have to use GFP_ATOMIC allocations in inet_netconf_notify_devconf(), meaning we are less likely to miss notifications under memory pressure, and wont touch precious memory reserves either and risk dropping incoming packets. inet_netconf_get_devconf() can also use GFP_KERNEL allocation. Fixes: edc9e748934c ("rtnl/ipv4: use netconf msg to advertise forwarding status") Fixes: 9e5511106f99 ("rtnl/ipv4: add support of RTM_GETNETCONF") Signed-off-by: Eric Dumazet <edumazet@xxxxxxxxxx> Cc: Nicolas Dichtel <nicolas.dichtel@xxxxxxxxx> Acked-by: Nicolas Dichtel <nicolas.dichtel@xxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/ipv4/devinet.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) --- a/net/ipv4/devinet.c +++ b/net/ipv4/devinet.c @@ -1814,7 +1814,7 @@ void inet_netconf_notify_devconf(struct struct sk_buff *skb; int err = -ENOBUFS; - skb = nlmsg_new(inet_netconf_msgsize_devconf(type), GFP_ATOMIC); + skb = nlmsg_new(inet_netconf_msgsize_devconf(type), GFP_KERNEL); if (!skb) goto errout; @@ -1826,7 +1826,7 @@ void inet_netconf_notify_devconf(struct kfree_skb(skb); goto errout; } - rtnl_notify(skb, net, 0, RTNLGRP_IPV4_NETCONF, NULL, GFP_ATOMIC); + rtnl_notify(skb, net, 0, RTNLGRP_IPV4_NETCONF, NULL, GFP_KERNEL); return; errout: if (err < 0) @@ -1883,7 +1883,7 @@ static int inet_netconf_get_devconf(stru } err = -ENOBUFS; - skb = nlmsg_new(inet_netconf_msgsize_devconf(-1), GFP_ATOMIC); + skb = nlmsg_new(inet_netconf_msgsize_devconf(-1), GFP_KERNEL); if (!skb) goto errout; @@ -2007,16 +2007,16 @@ static void inet_forward_change(struct n for_each_netdev(net, dev) { struct in_device *in_dev; + if (on) dev_disable_lro(dev); - rcu_read_lock(); - in_dev = __in_dev_get_rcu(dev); + + in_dev = __in_dev_get_rtnl(dev); if (in_dev) { IN_DEV_CONF_SET(in_dev, FORWARDING, on); inet_netconf_notify_devconf(net, NETCONFA_FORWARDING, dev->ifindex, &in_dev->cnf); } - rcu_read_unlock(); } } Patches currently in stable-queue which might be from edumazet@xxxxxxxxxx are queue-4.4/bonding-prevent-out-of-bound-accesses.patch queue-4.4/ipv4-do-not-abuse-gfp_atomic-in-inet_netconf_notify_devconf.patch queue-4.4/net-get-rid-of-an-signed-integer-overflow-in-ip_idents_reserve.patch queue-4.4/ipv4-accept-u8-in-ip_tos-ancillary-data.patch queue-4.4/ipv6-do-not-abuse-gfp_atomic-in-inet6_netconf_notify_devconf.patch queue-4.4/udp-restore-udplite-many-cast-delivery.patch queue-4.4/ipv4-fix-memory-leak-in-exception-case-for-splitting-tries.patch queue-4.4/tcp-do-not-set-rtt_min-to-1.patch