@@ -2655,7 +2655,7 @@ static int packet_release(struct socket *sock)
static int packet_do_bind(struct sock *sk, struct net_device *dev, __be16 proto)
{
struct packet_sock *po = pkt_sk(sk);
- const struct net_device *dev_curr;
+ struct net_device *dev_curr;
__be16 proto_curr;
bool need_rehook;
@@ -2679,15 +2679,13 @@ static int packet_do_bind(struct sock *sk, struct net_device *dev, __be16 proto)
po->num = proto;
po->prot_hook.type = proto;
-
- if (po->prot_hook.dev)
- dev_put(po->prot_hook.dev);
-
po->prot_hook.dev = dev;
po->ifindex = dev ? dev->ifindex : 0;
packet_cached_dev_assign(po, dev);
}
+ if (dev_curr)
+ dev_put(dev_curr);
if (proto == 0 || !need_rehook)
goto out_unlock;
This is a note to let you know that I have just added a patch titled packet: missing dev_put() in packet_do_bind() to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree which can be found at: http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.16.y-queue This patch is scheduled to be released in version 3.16.7-ckt17. If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.16.y-ckt tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Luis ------ From 26b1c3fa5972853b98c97fe6065a73e0096c2024 Mon Sep 17 00:00:00 2001 From: Lars Westerhoff <lars.westerhoff@newtec.eu> Date: Tue, 28 Jul 2015 01:32:21 +0300 Subject: packet: missing dev_put() in packet_do_bind() commit 158cd4af8dedbda0d612d448c724c715d0dda649 upstream. When binding a PF_PACKET socket, the use count of the bound interface is always increased with dev_hold in dev_get_by_{index,name}. However, when rebound with the same protocol and device as in the previous bind the use count of the interface was not decreased. Ultimately, this caused the deletion of the interface to fail with the following message: unregister_netdevice: waiting for dummy0 to become free. Usage count = 1 This patch moves the dev_put out of the conditional part that was only executed when either the protocol or device changed on a bind. Fixes: 902fefb82ef7 ('packet: improve socket create/bind latency in some cases') Signed-off-by: Lars Westerhoff <lars.westerhoff@newtec.eu> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Reviewed-by: Daniel Borkmann <dborkman@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Luis Henriques <luis.henriques@canonical.com> --- net/packet/af_packet.c | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-)