Re: [PATCH 165/190] Revert "mfd: mc13xxx: Fix a missing check of a register-read failure"

[Lee Jones]

On Wed, 21 Apr 2021, Greg Kroah-Hartman wrote:

> This reverts commit 9e28989d41c0eab57ec0bb156617a8757406ff8a.
> 
> Commits from @umn.edu addresses have been found to be submitted in "bad
> faith" to try to test the kernel community's ability to review "known
> malicious" changes.  The result of these submissions can be found in a
> paper published at the 42nd IEEE Symposium on Security and Privacy
> entitled, "Open Source Insecurity: Stealthily Introducing
> Vulnerabilities via Hypocrite Commits" written by Qiushi Wu (University
> of Minnesota) and Kangjie Lu (University of Minnesota).
> 
> Because of this, all submissions from this group must be reverted from
> the kernel tree and will need to be re-reviewed again to determine if
> they actually are a valid fix.  Until that work is complete, remove this
> change to ensure that no problems are being introduced into the
> codebase.
> 
> Cc: Kangjie Lu <kjlu@xxxxxxx>
> Cc: Lee Jones <lee.jones@xxxxxxxxxx>
> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> ---
>  drivers/mfd/mc13xxx-core.c | 4 +---
>  1 file changed, 1 insertion(+), 3 deletions(-)
> 
> diff --git a/drivers/mfd/mc13xxx-core.c b/drivers/mfd/mc13xxx-core.c
> index 1abe7432aad8..b2beb7c39cc5 100644
> --- a/drivers/mfd/mc13xxx-core.c
> +++ b/drivers/mfd/mc13xxx-core.c
> @@ -271,9 +271,7 @@ int mc13xxx_adc_do_conversion(struct mc13xxx *mc13xxx, unsigned int mode,
>  
>  	mc13xxx->adcflags |= MC13XXX_ADC_WORKING;
>  
> -	ret = mc13xxx_reg_read(mc13xxx, MC13XXX_ADC0, &old_adc0);
> -	if (ret)
> -		goto out;
> +	mc13xxx_reg_read(mc13xxx, MC13XXX_ADC0, &old_adc0);
>  
>  	adc0 = MC13XXX_ADC0_ADINC1 | MC13XXX_ADC0_ADINC2 |
>  	       MC13XXX_ADC0_CHRGRAWDIV;

Thanks for bringing this commit to my attention.

The associated LWN article was an interesting read and I have to say,
I was very disappointed to hear about the actions of these so called
researchers.

Upon re-review of the original commit, this one does appear valid.

Do I need to conduct anymore due diligence or can I drop this patch?

-- 
Lee Jones [李琼斯]
Senior Technical Lead - Developer Services
Linaro.org │ Open source software for Arm SoCs
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