Messages in this thread | | | Date | Tue, 5 Feb 2019 16:35:41 +0200 | From | Jarkko Sakkinen <> | Subject | Re: [PATCH v3] tpm/tpm_crb: Avoid unaligned reads in crb_recv() |
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On Tue, Feb 05, 2019 at 11:07:16AM +0000, Winkler, Tomas wrote: > > The current approach to read first 6 bytes from the response and then tail of > > the response, can cause the 2nd memcpy_fromio() to do an unaligned read > > (e.g. read 32-bit word from address aligned to a 16-bits), depending on how > > memcpy_fromio() is implemented. If this happens, the read will fail and the > > memory controller will fill the read with 1's. > > > > This was triggered by 170d13ca3a2f, which should be probably refined to check > > and react to the address alignment. Before that commit, on x86 > > memcpy_fromio() turned out to be memcpy(). By a luck GCC has done the right > > thing (from tpm_crb's perspective) for us so far, but we should not rely on that. > > Thus, it makes sense to fix this also in tpm_crb, not least because the fix can be > > then backported to stable kernels and make them more robust when compiled > > in differing environments. > > > > Cc: stable@vger.kernel.org > > Cc: James Morris <jmorris@namei.org> > > Cc: Tomas Winkler <tomas.winkler@intel.com> > > Cc: Jerry Snitselaar <jsnitsel@redhat.com> > > Fixes: 30fc8d138e91 ("tpm: TPM 2.0 CRB Interface") > > Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> > > Reviewed-by: Jerry Snitselaar <jsnitsel@redhat.com> > > --- > > v3: > > * Fix typo i.e. %s/reminding/remaining/g > > Why you haven't fixed all the typos I've pointed out? I think you missed that.
I saw only comment about remaining. Was there something else? Can fix.
/Jarkko
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