linux-kernel - Re: [PATCH] crypto: hisilicon - fix strncpy warning with strlcpy

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]

Message-ID: <b23433f8-d95d-8142-c830-fb92e5ccd4a1@linaro.org>
Date:   Thu, 4 Jun 2020 14:44:16 +0800
From:   Zhangfei Gao <zhangfei.gao@...aro.org>
To:     Herbert Xu <herbert@...dor.apana.org.au>
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Jonathan Cameron <Jonathan.Cameron@...wei.com>,
        wangzhou1 <wangzhou1@...ilicon.com>,
        linux-kernel@...r.kernel.org, linux-crypto@...r.kernel.org,
        kbuild-all@...ts.01.org
Subject: Re: [PATCH] crypto: hisilicon - fix strncpy warning with strlcpy



On 2020/6/4 下午2:18, Herbert Xu wrote:
> On Thu, Jun 04, 2020 at 02:10:37PM +0800, Zhangfei Gao wrote:
>>> Should this even allow truncation? Perhaps it'd be better to fail
>>> in case of an overrun?
>> I think we do not need consider overrun, since it at most copy size-1 bytes
>> to dest.
>>  From the manual: strlcpy()
>>         This  function  is  similar  to  strncpy(), but it copies at most
>> size-1 bytes to dest, always adds a terminating null
>>         byte,
>> And simple tested with smaller SIZE of interface.name,  only SIZE-1 is
>> copied, so it is safe.
>> -#define UACCE_MAX_NAME_SIZE    64
>> +#define UACCE_MAX_NAME_SIZE    4
> That's not what I meant.  As it is if you do exceed the limit the
> name is silently truncated.  Wouldn't it be better to fail the
> allocation instead?
I think it is fine.
1. Currently the name size is 64, bigger enough.
Simply grep in driver name, 64 should be enough.
We can make it larger when there is a request.
2. it does not matter what the name is, since it is just an interface.
cat /sys/class/uacce/hisi_zip-0/flags
cat /sys/class/uacce/his-0/flags
should be both fine to app only they can be distinguished.
3. It maybe a hard restriction to fail just because of a long name.

What do you think.

Thanks