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Date:   Mon, 29 Mar 2021 18:37:21 +0200
From:   Olaf Hering <olaf@aepfle.de>
To:     "Andrea Parri (Microsoft)" <parri.andrea@gmail.com>
Cc:     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>,
        Wei Liu <wei.liu@kernel.org>, Dexuan Cui <decui@microsoft.com>,
        Michael Kelley <mikelley@microsoft.com>,
        Saruhan Karademir <skarade@microsoft.com>,
        Juan Vazquez <juvazq@microsoft.com>,
        "James E.J. Bottomley" <jejb@linux.ibm.com>,
        "Martin K. Petersen" <martin.petersen@oracle.com>,
        linux-scsi@vger.kernel.org
Subject: Re: [PATCH 3/3] scsi: storvsc: Validate length of incoming packet in
 storvsc_on_channel_callback()
Message-ID: <YGICQc6HaYw8+uES@aepfle.de>
References: <20201217203321.4539-1-parri.andrea@gmail.com>
 <20201217203321.4539-4-parri.andrea@gmail.com>
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On Thu, Dec 17, Andrea Parri (Microsoft) wrote:

> Check that the packet is of the expected size at least, don't copy data
> past the packet.

> +		if (hv_pkt_datalen(desc) < sizeof(struct vstor_packet) -
> +				stor_device->vmscsi_size_delta) {
> +			dev_err(&device->device, "Invalid packet len\n");
> +			continue;
> +		}
> +

Sorry for being late:

It might be just cosmetic, but should this check be done prior the call to vmbus_request_addr()?


Unrelated: my copy of vmbus_request_addr() can return 0, which is apparently not handled by this loop in storvsc_on_channel_callback().


Olaf


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