Re: [PATCH 3/3] scsi: storvsc: Validate length of incoming packet in storvsc_on_channel_callback()
From: Andrea Parri <parri.andrea@gmail.com>
Date: 2021-03-30 09:09:21
Also in:
linux-scsi, lkml
From: Andrea Parri <parri.andrea@gmail.com>
Date: 2021-03-30 09:09:21
Also in:
linux-scsi, lkml
Hi Olaf, On Mon, Mar 29, 2021 at 06:37:21PM +0200, Olaf Hering wrote:
On Thu, Dec 17, Andrea Parri (Microsoft) wrote:quoted
Check that the packet is of the expected size at least, don't copy data past the packet.quoted
+ 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()?
TBH, I'm not immediately seeing why it 'should'; it could make sense to move the check on the packet data length.
Unrelated: my copy of vmbus_request_addr() can return 0, which is apparently not handled by this loop in storvsc_on_channel_callback().
Indeed, IDs of 0 are reserved for so called unsolicited messages; I think we should check that storvsc_on_io_completion() is not called on such messages. Thanks, Andrea