On Sun, May 24, 2020 at 9:49 PM Qiang Zhao <[email protected]> wrote: > > On Wed, May 23, 2020 at 5:22 PM Li Yang <[email protected]> > > -----Original Message----- > > From: Li Yang <[email protected]> > > Sent: 2020年5月23日 5:22 > > To: Kees Cook <[email protected]> > > Cc: Gustavo A. R. Silva <[email protected]>; Qiang Zhao > > <[email protected]>; linuxppc-dev <[email protected]>; > > moderated list:ARM/FREESCALE IMX / MXC ARM ARCHITECTURE > > <[email protected]>; lkml <[email protected]>; > > Gustavo A. R. Silva <[email protected]> > > Subject: Re: [PATCH] soc: fsl: qe: Replace one-element array and use > > struct_size() helper > > > > On Wed, May 20, 2020 at 10:24 PM Kees Cook <[email protected]> > > wrote: > > > > > > On Wed, May 20, 2020 at 06:52:21PM -0500, Li Yang wrote: > > > > On Mon, May 18, 2020 at 5:57 PM Kees Cook <[email protected]> > > wrote: > > > > > Hm, looking at this code, I see a few other things that need to be > > > > > fixed: > > > > > > > > > > 1) drivers/tty/serial/ucc_uart.c does not do a be32_to_cpu() > > > > > conversion > > > > > on the length test (understandably, a little-endian system has > > > > > never > > run > > > > > this code since it's ppc specific), but it's still wrong: > > > > > > > > > > if (firmware->header.length != fw->size) { > > > > > > > > > > compare to the firmware loader: > > > > > > > > > > length = be32_to_cpu(hdr->length); > > > > > > > > > > 2) drivers/soc/fsl/qe/qe.c does not perform bounds checking on the > > > > > per-microcode offsets, so the uploader might send data outside the > > > > > firmware buffer. Perhaps: > > > > > > > > We do validate the CRC for each microcode, it is unlikely the CRC > > > > check can pass if the offset or length is not correct. But you are > > > > probably right that it will be safer to check the boundary and fail > > > > > > Right, but a malicious firmware file could still match CRC but trick > > > the kernel code. > > > > > > > quicker before we actually start the CRC check. Will you come up > > > > with a formal patch or you want us to deal with it? > > > > > > It sounds like Gustavo will be sending one, though I don't think > > > either of us have the hardware to test it with, so if you could do > > > that part, that would be great! :) > > > > That will be great. I think Zhao Qiang can help with the testing part. > > > > Now the firmware are loaded in uboot, and kernel will do nothing for it. > So testing on it maybe need some extra codes both in driver and dts. > In the meanwhile, I am so busy on some high priority work that maybe test work > could not be done in time. > Once I am free, I will do it.
Thanks. You are right that most of the QE drivers doesn't support requesting firmware in kernel except the ucc_uart. So it probably can be tested with that driver without requiring code change. > > Best Regards > Qiang Zhao
