Subject: Re: [PATCH v3] net: asix: fix uninit value bugs

From: Andrew Lunn <[email-masked]>
Date: Sat, 14 Aug 2021 17:36:54 +0200

On Sat, Aug 14, 2021 at 04:55:05PM +0300, Pavel Skripkin wrote:
> Syzbot reported uninit-value in asix_mdio_read(). The problem was in
> missing error handling. asix_read_cmd() should initialize passed stack
> variable smsr, but it can fail in some cases. Then while condidition
> checks possibly uninit smsr variable.
> 
> Since smsr is uninitialized stack variable, driver can misbehave,
> because smsr will be random in case of asix_read_cmd() failure.
> Fix it by adding error handling and just continue the loop instead of
> checking uninit value.
> 
> Also, same loop was used in 3 other functions. Fixed uninit value bug
> in them too.

Hi Pavel

Which suggests it might make sense to refactor the code to make a
helper? I will leave you to decide if you want to do that.

The code does looks correct now.

	Andrew