Re: [Coverity] Untrusted user data in kernel

[Tomas Carnecky <tom@xxxxxxxxxxxxx>]

Oliver Neukum wrote:
> > But the difference between you example (cp /dev/zero /dev/mem) and 
> > passing unchecked data to the kernel is... you _can_ check the data and 
>
> This is the difference:
> static int open_port(struct inode * inode, struct file * filp)
> {
>         return capable(CAP_SYS_RAWIO) ? 0 : -EPERM;
> }
> (from mem.c)
OK, but my point was, whenever you can check the 'contents' of the data 
passed to the kernel, do it. You can't check if the data someone writes 
to /dev/mem is valid or not, but you can check for out-of-range/etc. 
data in ioctl & friends.
tom