Re: [PATCH] drivers/media/video/v4l2-compat-ioctl32.c: Check thereturn value of copy_to_user

From: Thiago Farina
Date: Tue Dec 21 2010 - 13:34:16 EST


On Tue, Dec 21, 2010 at 4:25 PM, Arnd Bergmann <arnd@xxxxxxxx> wrote:
> On Tuesday 21 December 2010 02:18:06 Thiago Farina wrote:
>> diff --git a/drivers/media/video/v4l2-compat-ioctl32.c b/drivers/media/video/v4l2-compat-ioctl32.c
>> index e30e8df..55825ec 100644
>> --- a/drivers/media/video/v4l2-compat-ioctl32.c
>> +++ b/drivers/media/video/v4l2-compat-ioctl32.c
>> @@ -206,7 +206,9 @@ static struct video_code __user *get_microcode32(struct video_code32 *kp)
>> Â Â Â Â Â* user address is invalid, the native ioctl will do
>> Â Â Â Â Â* the error handling for us
>> Â Â Â Â Â*/
>> - Â Â Â (void) copy_to_user(up->loadwhat, kp->loadwhat, sizeof(up->loadwhat));
>> + Â Â Â if (copy_to_user(up->loadwhat, kp->loadwhat, sizeof(up->loadwhat)))
>> + Â Â Â Â Â Â Â return NULL;
>> +
>> Â Â Â Â (void) put_user(kp->datasize, &up->datasize);
>> Â Â Â Â (void) put_user(compat_ptr(kp->data), &up->data);
>> Â Â Â Â return up;
>
> Did you read the comment above the code you changed?
>
Yes, I read, but I went ahead.

> You can probably change this function to look at the return code of
> copy_to_user, but then you need to treat the put_user return code
> the same, and change the comment.
>

Right, I will do the same with put_user, but I'm afraid of changing the comment.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/