lkml.org 
[lkml]   [2014]   [Oct]   [22]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
SubjectRe: [PATCH] sysctl: terminate strings also on \r
From
On Wed, Oct 22, 2014 at 4:26 PM, Andrew Morton
<akpm@linux-foundation.org> wrote:
> On Tue, 21 Oct 2014 13:21:37 -0700 Kees Cook <keescook@chromium.org> wrote:
>
>> From: Paul Wise <pabs3@bonedaddy.net>
>>
>> This partially mitigates a common strategy used by attackers for hiding
>> the full contents of strings in procfs from naive sysadmins who use cat,
>> more or sysctl to inspect the contents of strings in procfs.
>>
>> ...
>>
>> --- a/kernel/sysctl.c
>> +++ b/kernel/sysctl.c
>> @@ -1739,7 +1739,7 @@ static int _proc_do_string(char *data, int maxlen, int write,
>> while ((p - buffer) < *lenp && len < maxlen - 1) {
>> if (get_user(c, p++))
>> return -EFAULT;
>> - if (c == 0 || c == '\n')
>> + if (c == 0 || c == '\n' || c == '\r')
>> break;
>> data[len++] = c;
>> }
>
> There are no valid uses of \r in a procfs write?

I struggle to imagine one; everything I found that uses proc_dostring
seems to be names, paths, and commands.

-Kees

--
Kees Cook
Chrome OS Security


\
 
 \ /
  Last update: 2014-10-23 02:21    [W:0.113 / U:0.324 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site