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From: Dave Hansen <dave.hansen@intel.com>
To: Alexei Starovoitov <alexei.starovoitov@gmail.com>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	tech-board@lists.linuxfoundation.org,
	Song Liu <songliubraving@fb.com>,
	Kernel Team <Kernel-team@fb.com>
Cc: Borislav Petkov <bp@alien8.de>,
	brijesh.singh@amd.com, Dan Williams <dan.j.williams@intel.com>,
	Dave Hansen <dave.hansen@linux.intel.com>,
	"H. Peter Anvin" <hpa@zytor.com>,
	jane.chu@oracle.com,
	"Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
	LKML <linux-kernel@vger.kernel.org>,
	Andy Lutomirski <luto@kernel.org>, Ingo Molnar <mingo@redhat.com>,
	Peter Zijlstra <peterz@infradead.org>,
	seanjc@google.com,
	syzkaller-bugs <syzkaller-bugs@googlegroups.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Tom Lendacky <thomas.lendacky@amd.com>, X86 ML <x86@kernel.org>,
	Alexei Starovoitov <ast@kernel.org>,
	Daniel Borkmann <daniel@iogearbox.net>,
	John Fastabend <john.fastabend@gmail.com>,
	"open list:BPF (Safe dynamic programs and tools)" 
	<bpf@vger.kernel.org>
Subject: Re: [syzbot] WARNING in __change_page_attr_set_clr
Date: Sun, 25 Sep 2022 17:10:19 -0700	[thread overview]
Message-ID: <a2673df8-cf8a-b94a-68cd-1e2777fb5cf4@intel.com> (raw)
In-Reply-To: <CAADnVQ+SpNuUSRFte2Lm13QZiTXcWfn2eZw5Q+MP0SKwuJEXFg@mail.gmail.com>

On 9/25/22 14:55, Alexei Starovoitov wrote:
> And, sorry, "flip ro/rw every time" is not a good idea from
> security pov.
> There is a much better solution that stalled on the code review.
> In the meantime we'll land a quick fix to re-enable boot in -next
> in the coming days.

Peter, I remember an earlier version of your patch having some various
enforcement modes.  Since the strict enforcement has actually broken a
few things, should we resurrect the nicer soft detection mode?  Or,
maybe make the soft one the only mode for now?

Alexei, the "quick fix" looks sane to me at first glance.  Is there
something in there that's not viable long-term?

Also, the intention here was not to force any issues.  I thought the
earlier discussion resulted in a bpf fix and applying Peter's patch was
intended to catch _future_ issues.  I should have double-checked before
applying it.  My apologies.

  parent reply	other threads:[~2022-09-26  0:10 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <00000000000076f3a305e97e9229@google.com>
2022-09-25 16:44 ` [syzbot] WARNING in __change_page_attr_set_clr Dave Hansen
2022-09-25 21:55   ` Alexei Starovoitov
2022-09-25 23:16     ` Theodore Ts'o
2022-09-25 23:21     ` Randy Dunlap
2022-09-26  0:10     ` Dave Hansen [this message]
2022-09-26  8:24       ` Peter Zijlstra
2022-09-26  8:20     ` Peter Zijlstra
2022-09-26 13:28     ` [Tech-board] " Steven Rostedt

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