This is a note to let you know that I've just added the patch titled vhost_net: clear msg.control for non-zerocopy case during tx to the 3.9-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: vhost_net-clear-msg.control-for-non-zerocopy-case-during-tx.patch and it can be found in the queue-3.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From abaf419d84a3495c8779e2e0ecba2c3bba8063aa Mon Sep 17 00:00:00 2001 From: Jason Wang <jasowang@xxxxxxxxxx> Date: Wed, 5 Jun 2013 15:40:46 +0800 Subject: vhost_net: clear msg.control for non-zerocopy case during tx From: Jason Wang <jasowang@xxxxxxxxxx> [ Upstream commit 4364d5f96eed7994a2c625bd9216656e55fba0cb ] When we decide not use zero-copy, msg.control should be set to NULL otherwise macvtap/tap may set zerocopy callbacks which may decrease the kref of ubufs wrongly. Bug were introduced by commit cedb9bdce099206290a2bdd02ce47a7b253b6a84 (vhost-net: skip head management if no outstanding). This solves the following warnings: WARNING: at include/linux/kref.h:47 handle_tx+0x477/0x4b0 [vhost_net]() Modules linked in: vhost_net macvtap macvlan tun nfsd exportfs bridge stp llc openvswitch kvm_amd kvm bnx2 megaraid_sas [last unloaded: tun] CPU: 5 PID: 8670 Comm: vhost-8668 Not tainted 3.10.0-rc2+ #1566 Hardware name: Dell Inc. PowerEdge R715/00XHKG, BIOS 1.5.2 04/19/2011 ffffffffa0198323 ffff88007c9ebd08 ffffffff81796b73 ffff88007c9ebd48 ffffffff8103d66b 000000007b773e20 ffff8800779f0000 ffff8800779f43f0 ffff8800779f8418 000000000000015c 0000000000000062 ffff88007c9ebd58 Call Trace: [<ffffffff81796b73>] dump_stack+0x19/0x1e [<ffffffff8103d66b>] warn_slowpath_common+0x6b/0xa0 [<ffffffff8103d6b5>] warn_slowpath_null+0x15/0x20 [<ffffffffa0197627>] handle_tx+0x477/0x4b0 [vhost_net] [<ffffffffa0197690>] handle_tx_kick+0x10/0x20 [vhost_net] [<ffffffffa019541e>] vhost_worker+0xfe/0x1a0 [vhost_net] [<ffffffffa0195320>] ? vhost_attach_cgroups_work+0x30/0x30 [vhost_net] [<ffffffffa0195320>] ? vhost_attach_cgroups_work+0x30/0x30 [vhost_net] [<ffffffff81061f46>] kthread+0xc6/0xd0 [<ffffffff81061e80>] ? kthread_freezable_should_stop+0x70/0x70 [<ffffffff817a1aec>] ret_from_fork+0x7c/0xb0 [<ffffffff81061e80>] ? kthread_freezable_should_stop+0x70/0x70 Signed-off-by: Jason Wang <jasowang@xxxxxxxxxx> Acked-by: Michael S. Tsirkin <mst@xxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/vhost/net.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/drivers/vhost/net.c +++ b/drivers/vhost/net.c @@ -353,7 +353,8 @@ static void handle_tx(struct vhost_net * kref_get(&ubufs->kref); } vq->upend_idx = (vq->upend_idx + 1) % UIO_MAXIOV; - } + } else + msg.msg_control = NULL; /* TODO: Check specific error and bomb out unless ENOBUFS? */ err = sock->ops->sendmsg(NULL, sock, &msg, len); if (unlikely(err < 0)) { Patches currently in stable-queue which might be from jasowang@xxxxxxxxxx are queue-3.9/tuntap-forbid-changing-mq-flag-for-persistent-device.patch queue-3.9/packet-set-transport-header-before-doing-xmit.patch queue-3.9/netback-set-transport-header-before-passing-it-to-kernel.patch queue-3.9/net_sched-better-precise-estimation-on-packet-length-for-untrusted-packets.patch queue-3.9/tuntap-set-sock_zerocopy-flag-during-open.patch queue-3.9/tuntap-set-transport-header-before-passing-it-to-kernel.patch queue-3.9/tuntap-correct-the-return-value-in-tun_set_iff.patch queue-3.9/macvtap-set-transport-header-before-passing-skb-to-lower-device.patch queue-3.9/vhost_net-clear-msg.control-for-non-zerocopy-case-during-tx.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html