kernel with kasan compiled in fails to boot about kernel-sanitizers HOT 7 CLOSED

Hi,

There are no known issues with booting KASAN kernels. All configurations we tried work.

Please provide:

• commit hash/tree
• compiler version
• config (the one you referenced contains # CONFIG_KASAN is not set)
• how you boot it (e.g. qemu command line)

from kernel-sanitizers.

• commit hash/tree
  (I don't understand that, I know the words, but I just set kasan option on in the kernel
• compiler version
  is around these settings:
  https://597554.bugs.gentoo.org/attachment.cgi?id=451296
  ( ... gcc-5.4.0 ....), it's in that Gentoo bug report
• config (the one you referenced contains # CONFIG_KASAN is not set)
  You mean in this one:
  https://bugs.gentoo.org/attachment.cgi?id=451298
  True, what I meant was, onto such kernel config I added KASAN option.

The diff btwn that one and a KASAN enabled option one is (open attached file pls):
Kasan_161029_diff.txt

BTW. this: https://lkml.org/lkml/2016/6/21/541 seems to be of your writing. Appears to be the same issue in that Gentoo Bugzilla I gave links to ...

from kernel-sanitizers.

commit hash/tree (I don't understand that, I know the words, but I just set kasan option on in the kernel

How did you obtain kernel sources?
If it is git checkout, then provide output of git remote -v, git branch and git rev-parse HEAD commands.

Also, how you boot it (e.g. qemu command line)?

from kernel-sanitizers.

No, not from git. It is a regular hardened-sources Gentoo package:
https://packages.gentoo.org/packages/sys-kernel/hardened-sources
Also, while the bug I gave link to is about libvirt and qemu getting crashed
(
the cause actually likely some use-after-free condition according to PaX Team:
https://bugs.gentoo.org/show_bug.cgi?id=597554#c16
)...
[while the bug is about libvirt and qemu], I got that message on top with the ominous "" blinking forever with regular kernel install, not in VM, and regular booting.
And I can confirm that just adding those same KASAN option into the config file such as the one linked in this issue further above, only with the latest hardened-sources, which is:
4.7.10-r1
also stalls the booting at the ominous "" as explained on top.
Removing the KASAN options from the .config of 4.7.10-r1 kernel and recompiling, and it boots fine.
What itches me, is, like you wrote:
"The following program triggers use-after-free in kvm_irqfd_release: ..."
so what itches me is what is it that triggers "use-after-free in kvm_irqfd_release:" in my machines?
if I suspect correctly here...

from kernel-sanitizers.

I meant, like you wrote:
"The following program triggers use-after-free in kvm_irqfd_release: ..."
in:
https://lkml.org/lkml/2016/6/21/541

from kernel-sanitizers.

What I am looking for is step-by-step reproduction instructions, namely a sequence of commands that can copy-paste into my console to reproduce the issue. I can't debug if I can't reproduce it.
Or you can debug and fix it yourself. As I said there are no similar known issues, so I can't help straight away.

from kernel-sanitizers.

Closing, please reopen if the issue persists.

from kernel-sanitizers.