Re: [patch] fbdev: fix snprintf() limit in show_bl_curve()

On Fri, Aug 21, 2015 at 12:22:03PM +0300, Andy Shevchenko wrote:

On Fri, 2015-08-21 at 11:53 +0300, Dan Carpenter wrote:

quoted

The limit should be "PAGE_SIZE - len" instead of PAGE_SIZE.

Besides that was in the original code, the problem still might happen
when FB_BACKLIGHT_LEVELS is set to 171+ since snprintf() returns
desired length. I suppose you would change this to check len on each
iteration or change to scnprintf() if I get it correct.

Yeah, you're right.

If you pass a negative size to snprintf() it won't overflow, but it will
print an error.  I will send a v2 and change it to scnprintf().  I don't
think we will have 171 levels so it's not worth adding the check?

regards,
dan carpenter