From: David Miller <davem@davemloft.net>
To: vkuznets@redhat.com
Cc: sthemmin@microsoft.com, netdev@vger.kernel.org,
haiyangz@microsoft.com, linux-kernel@vger.kernel.org,
devel@linuxdriverproject.org
Subject: Re: [PATCH net-next] hv_netvsc: fix a race between netvsc_send() and netvsc_init_buf()
Date: Fri, 21 Oct 2016 11:28:01 -0400 (EDT) [thread overview]
Message-ID: <20161021.112801.585243295635293094.davem@davemloft.net> (raw)
In-Reply-To: <1476885181-3456-1-git-send-email-vkuznets@redhat.com>
From: Vitaly Kuznetsov <vkuznets@redhat.com>
Date: Wed, 19 Oct 2016 15:53:01 +0200
> Fix in commit 880988348270 ("hv_netvsc: set nvdev link after populating
> chn_table") turns out to be incomplete. A crash in
> netvsc_get_next_send_section() is observed on mtu change when the device
> is under load. The race I identified is: if we get to netvsc_send() after
> we set net_device_ctx->nvdev link in netvsc_device_add() but before we
> finish netvsc_connect_vsp()->netvsc_init_buf() send_section_map is not
> allocated and we crash. Unfortunately we can't set net_device_ctx->nvdev
> link after the netvsc_init_buf() call as during the negotiation we need
> to receive packets and on the receive path we check for it. It would
> probably be possible to split nvdev into a pair of nvdev_in and nvdev_out
> links and check them accordingly in get_outbound_net_device()/
> get_inbound_net_device() but this looks like an overkill.
>
> Check that send_section_map is allocated in netvsc_send().
>
> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Applied, thanks.
prev parent reply other threads:[~2016-10-21 15:28 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-10-19 13:53 [PATCH net-next] hv_netvsc: fix a race between netvsc_send() and netvsc_init_buf() Vitaly Kuznetsov
2016-10-20 8:36 ` Stephen Hemminger
2016-10-20 8:51 ` Vitaly Kuznetsov
2016-10-20 18:03 ` David Miller
2016-10-21 11:15 ` Vitaly Kuznetsov
2016-10-21 14:52 ` David Miller
2016-10-21 15:17 ` Vitaly Kuznetsov
2016-10-21 15:27 ` David Miller
2016-10-21 15:28 ` David Miller [this message]
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