Re: [PATCH RFC v2 0/6] staging: r8188eu: avoid uninit value bugs

Fabio M. De Francesco
2021-08-22T17:36:16Z

On Sunday, August 22, 2021 4:35:05 PM CEST Pavel Skripkin wrote:
> Hi, Greg, Larry and Phillip!
>
> I noticed, that new staging driver was added like 3 weeks ago and I decided
> to look at the code, because drivers in staging directory are always buggy.
>
> The first thing I noticed is *no one* was checking read operations result, but
> it can fail and driver may start writing random stack values into registers. It
> can cause driver misbehavior or device misbehavior.
>
> To avoid this type of bugs, I've changed rtw_read* API. Now all rtw_read
> funtions return an error, when something went wrong with usb transfer.
>
> It helps callers to break/return earlier and don't write random values to
> registers or to rely on random values.
>
> Why is this pacth series RFC?
> 1. I don't have this device and I cannot test these changes.
> 2. I don't know how to handle errors in each particular case. For now, function
> just returns or returns an error. That's all. I hope, driver maintainers will
> help with these bits.
> 3. I guess, I handled not all uninit value bugs here. I hope, I fixed
> at least half of them
>
> v1 -> v2:
> 1. Make rtw_read*() return an error instead of initializing pointer to error
> 2. Split one huge patch to smaller ones for each rtw_read{8,16,32} function
> changes
> 3. Add new macro for printing register values (It helps to not copy-paste error
> handling)
> 4. Removed {read,write}_macreg (Suggested by Phillip)
> 5. Rebased on top of staging-next
> 6. Cleaned checkpatch errors and warnings
>
> Only build-tested, since I don't have device with r8118eu chip
>
> Pavel Skripkin (6):
> staging: r8188eu: remove {read,write}_macreg
> staging: r8188eu: add helper macro for printing registers
> staging: r8188eu: add error handling of rtw_read8
> staging: r8188eu: add error handling of rtw_read16
> staging: r8188eu: add error handling of rtw_read32
> staging: r8188eu: make ReadEFuse return an int

Hi Pavel,

I've just read your v2 of the series. I had no time to read each and every line,
however, I suppose that I saw enough to say that I think they are a huge
improvement over v1. I really like your patches and if I were you, I'd drop
that RFC tag.

Thanks,

Fabio
v1 design.
not needed because