linux-kernel - Re: [PATCH] bitmap: bitmap_parse takes a kernel buffer instead of a user buffer

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: <20061003163936.d8e26629.akpm@osdl.org>
Date:	Tue, 3 Oct 2006 16:39:36 -0700
From:	Andrew Morton <akpm@...l.org>
To:	Reinette Chatre <reinette.chatre@...ux.intel.com>
Cc:	linux-kernel@...r.kernel.org,
	Inaky Perez-Gonzalez <inaky@...ux.intel.com>,
	Paul Jackson <pj@....com>
Subject: Re: [PATCH] bitmap: bitmap_parse takes a kernel buffer instead of a
 user buffer

On Tue, 3 Oct 2006 08:16:27 -0700
Reinette Chatre <reinette.chatre@...ux.intel.com> wrote:

> lib/bitmap.c:bitmap_parse() is a library function that received as input a  user buffer. This seemed to have originated from the way the write_proc function of the /proc filesystem operates.
> 
> This function will be useful for other uses as well; for example, taking input  for /sysfs instead of /proc, so it was changed to accept kernel buffers. We have this use for the Linux UWB project, as part as the upcoming bandwidth allocator code.
> 
> Only a few routines used this function and they were changed too.

Fair enough.  But this:

>  
> -	err = cpumask_parse(buffer, count, new_value);
> +	kbuf = kmalloc(count, GFP_KERNEL);
> +	if (kbuf == NULL)
> +		return -ENOMEM;
> +	ret = copy_from_user(kbuf, buffer, count);
> +	if (ret != 0) {
> +		kfree(kbuf);
> +		return -EFAULT;
> +	}
> +	err = cpumask_parse(kbuf, count, new_value);
> +	kfree(kbuf);
>  	if (err)
>  		return err;
>
> ...
>
> -	err = cpumask_parse(buffer, count, new_value);
> +	kbuf = kmalloc(count, GFP_KERNEL);
> +	if (kbuf == NULL)
> +		return -ENOMEM;
> +	ret = copy_from_user(kbuf, buffer, count);
> +	if (ret != 0) {
> +		kfree(kbuf);
> +		return -EFAULT;
> +	}
> +	err = cpumask_parse(kbuf, count, new_value);
> +	kfree(kbuf);
>  	if (err)
>  		return err;
>  

is sending us a message ;)

How about adding a new bitmap_parse_user() (and cpumask_parse_user()) which
does the above?
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/