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SubjectRe: tip -ENOBOOT - bisected to locking/refcounts, x86/asm: Implement fast refcount overflow protection
On Thu, Aug 31, 2017 at 6:58 AM, Mike Galbraith <efault@gmx.de> wrote:
> gdb) list *in6_dev_get+0x10
> 0xffffffff8166d3d0 is in in6_dev_get (./include/net/addrconf.h:318).
> 313 {
> 314 struct inet6_dev *idev;
> 315
> 316 rcu_read_lock();
> 317 idev = rcu_dereference(dev->ip6_ptr);
> 318 if (idev)
> 319 refcount_inc(&idev->refcnt);
> 320 rcu_read_unlock();
> 321 return idev;
> 322

And this is a completely different refcount from the other that
tripped. This one is quite simple, too, though I see it uses
refcount_dec(), which is a path to saturation. I've sent a patch to
try to clarify this further...

-Kees

--
Kees Cook
Pixel Security

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