[lkml]   [2017]   [Jul]   [17]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: [PATCH 14/22] [media] usbvision-i2c: fix format overflow warning
On 17/07/17 14:57, Arnd Bergmann wrote:
> On Mon, Jul 17, 2017 at 2:53 PM, Hans Verkuil <> wrote:
>> On 14/07/17 14:07, Arnd Bergmann wrote:
>>> gcc-7 notices that we copy a fixed length string into another
>>> string of the same size, with additional characters:
>>> drivers/media/usb/usbvision/usbvision-i2c.c: In function 'usbvision_i2c_register':
>>> drivers/media/usb/usbvision/usbvision-i2c.c:190:36: error: '%d' directive writing between 1 and 11 bytes into a region of size between 0 and 47 [-Werror=format-overflow=]
>>> sprintf(usbvision->, "%s-%d-%s",,
>>> ^~~~~~~~~~
>>> drivers/media/usb/usbvision/usbvision-i2c.c:190:2: note: 'sprintf' output between 4 and 76 bytes into a destination of size 48
>>> We know this is fine as the template name is always "usbvision", so
>>> we can easily avoid the warning by using this as the format string
>>> directly.
>> Hmm, how about replacing sprintf by snprintf? That feels a lot safer (this is very
>> old code, it's not surprising it is still using sprintf).
> With snprintf(), you will still get a -Wformat-truncation warning. One
> of my patches
> disables that warning by default, but Mauro likes build-testing with
> "make W=1", so
> it would still show up then.
> However, we can do both: replace the string and use snprintf().

Yes please!



 \ /
  Last update: 2017-07-17 15:00    [W:0.034 / U:9.208 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site