From: Thomas Gleixner <tglx@linutronix.de>
To: Dmitry Vyukov <dvyukov@google.com>,
syzbot <syzbot+dc1fa714cb070b184db5@syzkaller.appspotmail.com>
Cc: LKML <linux-kernel@vger.kernel.org>,
syzkaller-bugs <syzkaller-bugs@googlegroups.com>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
the arch/x86 maintainers <x86@kernel.org>,
Oleg Nesterov <oleg@redhat.com>
Subject: Re: PANIC: double fault in fixup_bad_iret
Date: Fri, 29 May 2020 18:06:01 +0200 [thread overview]
Message-ID: <87lflan2ty.fsf@nanos.tec.linutronix.de> (raw)
In-Reply-To: <87o8q6n38p.fsf@nanos.tec.linutronix.de>
Thomas Gleixner <tglx@linutronix.de> writes:
> Dmitry Vyukov <dvyukov@google.com> writes:
>> On Fri, May 29, 2020 at 3:14 PM syzbot
>> <syzbot+dc1fa714cb070b184db5@syzkaller.appspotmail.com> wrote:
>>
>> From the reproducer it seems to be either x86 related or ptrace
>> related.
>>
>>> RIP: 0010:fixup_bad_iret+0x24/0x170 arch/x86/kernel/traps.c:665
>
> as a quick assumption that's related to KASAN in fixup_bad_iret() which
> is a frightenly bad idea. I'm about to verify.
Exactly as I assumed. With KASAN off, no problem, with KASAN on, insta
crash.
This function needs to be excluded from KASAN or any other of those
magic function. I need to walk the dogs first and will look into fixing
it later.
Thanks,
tglx
next prev parent reply other threads:[~2020-05-29 16:06 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-29 13:14 PANIC: double fault in fixup_bad_iret syzbot
2020-05-29 13:20 ` Dmitry Vyukov
2020-05-29 15:57 ` Thomas Gleixner
2020-05-29 16:06 ` Thomas Gleixner [this message]
2020-05-29 16:07 ` Peter Zijlstra
2020-05-29 17:11 ` Peter Zijlstra
2020-05-30 7:39 ` Thomas Gleixner
2020-05-31 9:32 ` Dmitry Vyukov
2020-06-01 12:40 ` Marco Elver
2020-06-02 9:41 ` Peter Zijlstra
2020-06-02 17:51 ` Marco Elver
2020-06-02 17:58 ` Peter Zijlstra
2020-06-15 22:31 ` [tip: x86/entry] kasan: Bump required compiler version tip-bot2 for Marco Elver
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