linux-kernel - Re: Re: [PATCH net-next v2] net: thunderx: Fix format-truncation warning in bgx_acpi_match

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] [day] [month] [year] [list]

Message-ID: <7334d51a-65d3-43ed-8a33-eedeeb810045@oracle.com>
Date: Fri, 11 Jul 2025 15:47:43 +0530
From: ALOK TIWARI <alok.a.tiwari@...cle.com>
To: Jakub Kicinski <kuba@...nel.org>
Cc: sgoutham@...vell.com, andrew+netdev@...n.ch, davem@...emloft.net,
        edumazet@...gle.com, pabeni@...hat.com, horms@...nel.org,
        netdev@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
        darren.kenny@...cle.com, linux-kernel@...r.kernel.org
Subject: Re: Re: [PATCH net-next v2] net: thunderx: Fix format-truncation
 warning in bgx_acpi_match_id()



On 7/11/2025 4:04 AM, Jakub Kicinski wrote:
> On Tue,  8 Jul 2025 10:52:43 -0700 Alok Tiwari wrote:
>> Increase the buffer size from 5 to 8 and use sizeof(bgx_sel) in
>> snprintf() to ensure safety and suppress the warning.
>>
>> Build warning:
>>    CC      drivers/net/ethernet/cavium/thunder/thunder_bgx.o
>>    drivers/net/ethernet/cavium/thunder/thunder_bgx.c: In function
>> ‘bgx_acpi_match_id’:
>>    drivers/net/ethernet/cavium/thunder/thunder_bgx.c:1434:27: error: ‘%d’
>> directive output may be truncated writing between 1 and 3 bytes into a
>> region of size 2 [-Werror=format-truncation=]
>>      snprintf(bgx_sel, 5, "BGX%d", bgx->bgx_id);
>>                               ^~
>>    drivers/net/ethernet/cavium/thunder/thunder_bgx.c:1434:23: note:
>> directive argument in the range [0, 255]
>>      snprintf(bgx_sel, 5, "BGX%d", bgx->bgx_id);
>>                           ^~~~~~~
>>    drivers/net/ethernet/cavium/thunder/thunder_bgx.c:1434:2: note:
>> ‘snprintf’ output between 5 and 7 bytes into a destination of size 5
>>      snprintf(bgx_sel, 5, "BGX%d", bgx->bgx_id);
> 
> Hm, why are you making it 8 when the max length is 7 ? 🤔️

yes, 7 is max range. I will send v3 with this change.

Thanks,
Alok