Re: [PATCH 07/13] kexec: Implementation of new syscall kexec_file_load

Vivek Goyal
2014-06-16T21:43:56Z

On Mon, Jun 16, 2014 at 02:25:07PM -0700, H. Peter Anvin wrote:
> On 06/16/2014 02:09 PM, Borislav Petkov wrote:
> >
> > Nah, I don't feel strongly about it - I just don't trust userspace and
> > think that every value we get from it should be "sanitized".
> >
>
> Borislav and I talked about this briefly over IRC. A key part of that
> is that if userspace could manipulate this system call to consume an
> unreasonable amount of memory, we would have a problem, for example if
> this code used vzalloc() instead of kzalloc(). However, since
> kmalloc/kzalloc implies a relatively restrictive limit on the memory
> allocation size anyway, well short of anything that could cause OOM
> problems, that pretty much solves the problem.

Actually currently I am using vzalloc() for command line buffer
allocation.

image->cmdline_buf = vzalloc(cmdline_len);
if (!image->cmdline_buf)
goto out;

Should I switch to using kzalloc() instead?

Thanks
Vivek