Re: [PATCH] fs/binfmt_elf.c: allocate initialized memory in fill_thread_core_info()

[Al Viro]

On Tue, May 12, 2020 at 02:09:01AM +0100, Al Viro wrote:
> On Tue, Apr 21, 2020 at 10:14:25AM +0200, Alexander Potapenko wrote:
> > > Not lately and I would also like to hear the details; which regset it is?
> > > Should be reasonably easy to find - just memset() the damn thing to something
> > > recognizable, do whatever triggers that KMSAN report and look at that
> > > resulting coredump.
> > 
> > The bug is easily triggerable by the following program:
> > 
> > ================================================
> > int main() {
> >   volatile char *c = 0;
> >   (void)*c;
> >   return 0;
> > }
> > ================================================
> > 
> > in my QEMU after I do `ulimit -c 10000`.
> 
> .config, please - I hadn't been able to reproduce that on mine.
> Coredump obviously does happen, but not a trace of the poison
> is there - with your memset(data, 0xae, size) added, that is.

Actually, more interesting question would be your /proc/cpuinfo...