From: Wei Liu <wei.liu@kernel.org>
To: Andrea Parri <parri.andrea@gmail.com>
Cc: Wei Liu <wei.liu@kernel.org>,
linux-kernel@vger.kernel.org, linux-hyperv@vger.kernel.org,
"K . Y . Srinivasan" <kys@microsoft.com>,
Haiyang Zhang <haiyangz@microsoft.com>,
Stephen Hemminger <sthemmin@microsoft.com>,
Michael Kelley <mikelley@microsoft.com>,
Juan Vazquez <juvazq@microsoft.com>,
Saruhan Karademir <skarade@microsoft.com>
Subject: Re: [PATCH v2 2/7] Drivers: hv: vmbus: Avoid double fetch of msgtype in vmbus_on_msg_dpc()
Date: Wed, 2 Dec 2020 13:40:04 +0000 [thread overview]
Message-ID: <20201202134004.5tgrbyijrhvwwmk2@liuwe-devbox-debian-v2> (raw)
In-Reply-To: <20201202133716.GA22763@andrea>
On Wed, Dec 02, 2020 at 02:37:16PM +0100, Andrea Parri wrote:
> > > @@ -1072,12 +1073,19 @@ void vmbus_on_msg_dpc(unsigned long data)
> > > /* no msg */
> > > return;
> > >
> > > + /*
> > > + * The hv_message object is in memory shared with the host. The host
> > > + * could erroneously or maliciously modify such object. Make sure to
> > > + * validate its fields and avoid double fetches whenever feasible.
> > > + */
> > > +
> > > hdr = (struct vmbus_channel_message_header *)msg->u.payload;
> > > + msgtype = hdr->msgtype;
> >
> > Should READ_ONCE be used here?
>
> I think it should. Thank you for pointing this out.
Glad I can help.
The same comment applies to other patches as well, of course.
Wei.
>
> Andrea
next prev parent reply other threads:[~2020-12-02 13:41 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-02 9:22 [PATCH v2 0/7] Drivers: hv: vmbus: More VMBus-hardening changes Andrea Parri (Microsoft)
2020-12-02 9:22 ` [PATCH v2 1/7] Drivers: hv: vmbus: Initialize memory to be sent to the host Andrea Parri (Microsoft)
2020-12-02 9:22 ` [PATCH v2 2/7] Drivers: hv: vmbus: Avoid double fetch of msgtype in vmbus_on_msg_dpc() Andrea Parri (Microsoft)
2020-12-02 12:22 ` Wei Liu
2020-12-02 13:37 ` Andrea Parri
2020-12-02 13:40 ` Wei Liu [this message]
2020-12-02 14:14 ` Andrea Parri
2020-12-02 9:22 ` [PATCH v2 3/7] Drivers: hv: vmbus: Avoid double fetch of payload_size " Andrea Parri (Microsoft)
2020-12-02 9:22 ` [PATCH v2 4/7] Drivers: hv: vmbus: Copy the hv_message object " Andrea Parri (Microsoft)
2020-12-06 18:39 ` Michael Kelley
2020-12-06 21:33 ` Andrea Parri
2020-12-02 9:22 ` [PATCH v2 5/7] Drivers: hv: vmbus: Avoid use-after-free in vmbus_onoffer_rescind() Andrea Parri (Microsoft)
2020-12-02 9:22 ` [PATCH v2 6/7] Drivers: hv: vmbus: Resolve race condition " Andrea Parri (Microsoft)
2020-12-02 9:22 ` [PATCH v2 7/7] Drivers: hv: vmbus: Do not allow overwriting vmbus_connection.channels[] Andrea Parri (Microsoft)
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