Re: [PATCH v2] net: usb: dm9601: fix uninitialized variable use in dm9601_mdio_read

[Greg KH]

On Tue, Oct 10, 2023 at 12:26:14AM +0200, Javier Carrasco wrote:
> syzbot has found an uninit-value bug triggered by the dm9601 driver [1].
> 
> This error happens because the variable res is not updated if the call
> to dm_read_shared_word returns an error. In this particular case -EPROTO
> was returned and res stayed uninitialized.
> 
> This can be avoided by checking the return value of dm_read_shared_word
> and propagating the error if the read operation failed.
> 
> [1] https://syzkaller.appspot.com/bug?extid=1f53a30781af65d2c955
> 
> Signed-off-by: Javier Carrasco <javier.carrasco.cruz@xxxxxxxxx>
> Reported-and-tested-by: syzbot+1f53a30781af65d2c955@xxxxxxxxxxxxxxxxxxxxxxxxx
> ---
> Changes in v2:
> - Remove unnecessary 'err == 0' case
> - Link to v1: https://lore.kernel.org/r/20231009-topic-dm9601_uninit_mdio_read-v1-1-d4d775e24e3b@xxxxxxxxx
> ---
>  drivers/net/usb/dm9601.c | 7 ++++++-
>  1 file changed, 6 insertions(+), 1 deletion(-)

What commit id does this fix?

thanks,

greg k-h