From: Wei Liu <wei.liu@kernel.org>
To: "Andrea Parri (Microsoft)" <parri.andrea@gmail.com>
Cc: linux-kernel@vger.kernel.org,
"K . Y . Srinivasan" <kys@microsoft.com>,
Haiyang Zhang <haiyangz@microsoft.com>,
Stephen Hemminger <sthemmin@microsoft.com>,
Wei Liu <wei.liu@kernel.org>,
linux-hyperv@vger.kernel.org,
Michael Kelley <mikelley@microsoft.com>,
Juan Vazquez <juvazq@microsoft.com>,
Saruhan Karademir <skarade@microsoft.com>
Subject: Re: [PATCH 4/6] Drivers: hv: vmbus: Avoid use-after-free in vmbus_onoffer_rescind()
Date: Tue, 24 Nov 2020 16:26:33 +0000 [thread overview]
Message-ID: <20201124162633.n7zlpte6f7zfhn6z@liuwe-devbox-debian-v2> (raw)
In-Reply-To: <20201118143649.108465-5-parri.andrea@gmail.com>
On Wed, Nov 18, 2020 at 03:36:47PM +0100, Andrea Parri (Microsoft) wrote:
> When channel->device_obj is non-NULL, vmbus_onoffer_rescind() could
> invoke put_device(), that will eventually release the device and free
> the channel object (cf. vmbus_device_release()). However, a pointer
> to the object is dereferenced again later to load the primary_channel.
> The use-after-free can be avoided by noticing that this load/check is
> redundant if device_obk is non-NULL: primary_channel must be NULL if
device_obk -> device_obj
> device_obj is non-NULL, cf. vmbus_add_channel_work().
>
Missing a Fixes tag?
> Reported-by: Juan Vazquez <juvazq@microsoft.com>
> Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
> ---
> drivers/hv/channel_mgmt.c | 3 +--
> 1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/drivers/hv/channel_mgmt.c b/drivers/hv/channel_mgmt.c
> index 5bc5eef5da159..4072fd1f22146 100644
> --- a/drivers/hv/channel_mgmt.c
> +++ b/drivers/hv/channel_mgmt.c
> @@ -1116,8 +1116,7 @@ static void vmbus_onoffer_rescind(struct vmbus_channel_message_header *hdr)
> vmbus_device_unregister(channel->device_obj);
> put_device(dev);
> }
> - }
> - if (channel->primary_channel != NULL) {
> + } else if (channel->primary_channel != NULL) {
> /*
> * Sub-channel is being rescinded. Following is the channel
> * close sequence when initiated from the driveri (refer to
> --
> 2.25.1
>
next prev parent reply other threads:[~2020-11-24 16:27 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-18 14:36 [PATCH 0/6] Drivers: hv: vmbus: More VMBus-hardening changes Andrea Parri (Microsoft)
2020-11-18 14:36 ` [PATCH 1/6] Drivers: hv: vmbus: Initialize memory to be sent to the host Andrea Parri (Microsoft)
2020-12-06 16:59 ` Michael Kelley
2020-12-06 17:54 ` Andrea Parri
2020-11-18 14:36 ` [PATCH 2/6] Drivers: hv: vmbus: Avoid double fetch of msgtype in vmbus_on_msg_dpc() Andrea Parri (Microsoft)
2020-12-06 17:10 ` Michael Kelley
2020-12-06 18:05 ` Andrea Parri
2020-11-18 14:36 ` [PATCH 3/6] Drivers: hv: vmbus: Avoid double fetch of payload_size " Andrea Parri (Microsoft)
2020-12-06 17:14 ` Michael Kelley
2020-12-06 18:20 ` Andrea Parri
2020-11-18 14:36 ` [PATCH 4/6] Drivers: hv: vmbus: Avoid use-after-free in vmbus_onoffer_rescind() Andrea Parri (Microsoft)
2020-11-24 16:26 ` Wei Liu [this message]
2020-11-24 19:54 ` Andrea Parri
2020-12-06 17:23 ` Michael Kelley
2020-11-18 14:36 ` [PATCH 5/6] Drivers: hv: vmbus: Resolve race condition " Andrea Parri (Microsoft)
2020-11-18 14:36 ` [PATCH 6/6] Drivers: hv: vmbus: Do not allow overwriting vmbus_connection.channels[] Andrea Parri (Microsoft)
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