Re: SLB9670 TPM module crash

[Jarkko Sakkinen]

On Sat May 18, 2024 at 2:25 PM EEST, Jarkko Sakkinen wrote:
> On Sat May 18, 2024 at 2:21 PM EEST, Parthiban wrote:
> > Dear James Bottomley,
> >
> > The following crash is observed in the current mainline kernel and I have tried the
> > git bisect to narrow it down. Bisect points to the below commit, which got merged as
> > part of [1]. I tried reverting the below commit and the TPM loads fine.
> >
> > commit 1b6d7f9eb150305dcb0da4f7101a8d30dcdf0497
> > Author: James Bottomley <James.Bottomley@xxxxxxxxxxxxxxxxxxxxx>
> > Date:   Mon Apr 29 16:28:07 2024 -0400
> >
> >     tpm: add session encryption protection to tpm2_get_random()
> >     
> >     If some entity is snooping the TPM bus, they can see the random
> >     numbers we're extracting from the TPM and do prediction attacks
> >     against their consumers.  Foil this attack by using response
> >     encryption to prevent the attacker from seeing the random sequence.
> >     
> >     Signed-off-by: James Bottomley <James.Bottomley@xxxxxxxxxxxxxxxxxxxxx>
> >     Reviewed-by: Jarkko Sakkinen <jarkko@xxxxxxxxxx>
> >     Tested-by: Jarkko Sakkinen <jarkko@xxxxxxxxxx>
> >     Signed-off-by: Jarkko Sakkinen <jarkko@xxxxxxxxxx>
> >
> >  drivers/char/tpm/tpm2-cmd.c | 21 +++++++++++++++++----
> >  1 file changed, 17 insertions(+), 4 deletions(-)
> >
> > [   11.551988] tpm_tis_spi spi0.1: 2.0 TPM (device-id 0x1B, rev-id 22)
> > [   11.563036] spi_master spi0: will run message pump with realtime priority
>
>
> Explanation and workaround: https://lore.kernel.org/linux-integrity/D1C1KL7Q27P9.39BH0Z4EMBBUG@xxxxxxxxxx/

Oops completely wrong for this issue! Sorry I overlooked.

So fix is in progress for __request_module() issue. See this
discussion for reference:

https://lore.kernel.org/linux-integrity/119dc5ed-f159-41be-9dda-1a056f29888d@notapiano/

BR, Jarkko