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

Al Viro
2020-05-12T01:09:08Z

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.