Re: [PATCH] mdadm: protecting sys_name overflow

[Nikhil Kshirsagar <nkshirsa@redhat.com>]

Hi Jes,

Apologies for the wrong indentation. I will re-post the patch.

Thanks,
nikhil.

On 06/16/2016 12:10 AM, Jes Sorensen wrote:
> Nikhil Kshirsagar <nkshirsa@redhat.com> writes:
>> Hello,
>>
>> Devices with names larger than 31 bytes will overflow the sys_name array.
>>
>> This patch enables mdadm to fail and log a message if a long device name
>> is going to cause a buffer overflow.
>>
>> Signed-off-by: Nikhil Kshirsagar <nkshirsa@redhat.com>
>>
>> From 705aec84c6abf5b09c4202aec7cade9824ca7f12 Mon Sep 17 00:00:00 2001
>> From: root <root@nkshirsa.pnq.csb>
>> Date: Wed, 15 Jun 2016 15:23:12 +0530
>> Subject: [PATCH] Protecting overflow of sys_name. If a long device name is
>>  going to cause a buffer overflow, we fail with a log message.
>>
>> ---
>>  sysfs.c | 9 +++++++++
>>  1 file changed, 9 insertions(+)
>>
>> diff --git a/sysfs.c b/sysfs.c
>> index 8379ca8..68b8b95 100644
>> --- a/sysfs.c
>> +++ b/sysfs.c
>> @@ -283,6 +283,15 @@ struct mdinfo *sysfs_read(int fd, char *devnm, unsigned long options)
>>  			}
>>  
>>  		}
>> +                /*  strlen computes length of string *not* including the terminating null character. */
>> +
>> +                if(strlen(de->d_name) >= sizeof(dev->sys_name))
>> +                {
>> +                  pr_err("Device name %s larger than currently supported by mdadm\n",de->d_name);
>> +                  free(dev);
>> +                  goto abort;
>> +
>> +                }
> Nikhil,
>
> Please respect the coding style of mdadm. Code indents at 8 characters
> using a tab, not whitespace, and brackets should be placed correctly.
>
> Just like with kernel code.
>
> Jes