Re: [syzbot] WARNING in ex_handler_fprestore

[Thomas Gleixner]

On Tue, May 25 2021 at 17:33, Andy Lutomirski wrote:
> On 5/24/21 1:51 AM, syzbot wrote:
> I entirely believe that this bug is real and that syzbot bisected it
> correctly, but I'm puzzled by the reproducer.  It says:

The bug is real and the bisection is correct.

> ptrace$setregs(0xd, r0, 0x0, &(0x7f0000000080))
>
> I would really, really expect this to result from PTRACE_SETREGSET or
> PTRACE_SETFPREGS, but this is PTRACE_SETREGS.
>
> Am I missing something really obvious here?

That ptrace muck is a red herring and has nothing to do with it.

I decoded it fully by now and will send out coherent info (and hopefully
a patch) tomorrow with brain awake. Time for bed here...

Thanks,

        tglx