linux-kernel - Re: [PATCH v3 3/6] staging: r8188eu: add error handling of rtw

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Thu, 26 Aug 2021 01:45:47 +0200
From:   "Fabio M. De Francesco" <fmdefrancesco@...il.com>
To:     Larry.Finger@...inger.net, phil@...lpotter.co.uk,
        gregkh@...uxfoundation.org, straube.linux@...il.com,
        Pavel Skripkin <paskripkin@...il.com>
Cc:     linux-staging@...ts.linux.dev, linux-kernel@...r.kernel.org,
        Pavel Skripkin <paskripkin@...il.com>
Subject: Re: [PATCH v3 3/6] staging: r8188eu: add error handling of rtw_read8

On Tuesday, August 24, 2021 9:27:27 AM CEST Pavel Skripkin wrote:
> _rtw_read8 function can fail in case of usb transfer failure. But
> previous function prototype wasn't designed to return an error to
> caller. It can cause a lot uninit value bugs all across the driver code,
> since rtw_read8() returns local stack variable to caller.
> 
> Fix it by changing the prototype of this function. Now it returns an
> int: 0 on success, negative error value on failure and callers should pass
> the pointer to storage location for register value.
> 
> Signed-off-by: Pavel Skripkin <paskripkin@...il.com>

Dear Pavel,

I have to inform you that building patch v3 3/6 with gcc (version 11.1.1 20210721 
[revision 076930b9690ac3564638636f6b13bbb6bc608aea] (SUSE Linux)), gives
the following warning:

drivers/staging/r8188eu/os_dep/ioctl_linux.c:2258:13: warning: variable ‘error’ set but not used [-Wunused-but-set-variable]
 2258 |         int error;
      |             ^~~~~

I'm sorry, but I guess that for some reason previously I had only built v2 of your patch 
which had no warnings at all. 

Unfortunately, introducing warnings is not allowed.

While we are at this, I can also confirm that GCC 11.1.1 _does_ _not_ emit the warning 
that has been reported by the kernel test robot. 

Regards,

Fabio