Re: [PATCH] tpm: Move dereference after NULL check in tpm_buf_check_hmac_response

Jarkko Sakkinen
2024-07-15T11:25:19Z

On Tue Jul 9, 2024 at 5:33 AM EEST, Hao Ge wrote:
> From: Hao Ge <gehao@kylinos.cn>
>
> We shouldn't dereference "auth" until after we have checked that it is
> non-NULL.
>
> Fixes: 7ca110f2679b ("tpm: Address !chip->auth in tpm_buf_append_hmac_session*()")
> Signed-off-by: Hao Ge <gehao@kylinos.cn>

Also lacking:

Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Closes: https://lore.kernel.org/linux-integrity/3b1755a9-b12f-42fc-b26d-de2fe4e13ec2@stanley.mountain/T/#u

What is happening here is that my commit exposed pre-existing bug to
static analysis but it did not introduce a new regression. I missed
from your patch how did you ended up to your conclusions.

Please *do not* ignore the sources next time. Either explain how the bug
was found or provide the reporting source. You are essentially taking
credit and also blame from the work that you did not accomplish
yourself, which is both wrong and dishonest.

BR, Jarkko