From: Peter Zijlstra <peterz@infradead.org>
To: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Vince Weaver <vincent.weaver@maine.edu>,
linux-kernel@vger.kernel.org, Ingo Molnar <mingo@redhat.com>,
Arnaldo Carvalho de Melo <acme@kernel.org>,
Andy Lutomirski <luto@kernel.org>
Subject: Re: perf: perf_fuzzer triggers vmalloc_fault (then crashes)
Date: Mon, 24 Oct 2016 13:16:35 +0200 [thread overview]
Message-ID: <20161024111635.GH3102@twins.programming.kicks-ass.net> (raw)
In-Reply-To: <20161024111402.fv2sswwgnx6qm3ic@treble>
On Mon, Oct 24, 2016 at 06:14:02AM -0500, Josh Poimboeuf wrote:
> > Josh, Andy, any clue on how I should go about fixing this?
>
> This is a bug in the unwinder. The NMI hit in the entry code right
> after setting up the stack pointer from cpu_current_top_of_stack, so the
> kernel stack was empty. __unwind_start() tried to dereference the
> pointer (0xffffc90008500000) at the top of the stack. I'll make a
> patch.
Great, thanks!
next prev parent reply other threads:[~2016-10-24 11:16 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-10-22 3:05 perf: perf_fuzzer triggers vmalloc_fault (then crashes) Vince Weaver
2016-10-24 10:18 ` Peter Zijlstra
2016-10-24 11:14 ` Josh Poimboeuf
2016-10-24 11:16 ` Peter Zijlstra [this message]
2016-10-24 13:31 ` [PATCH] x86/unwind: fix empty stack dereference in guess unwinder Josh Poimboeuf
2016-10-25 10:30 ` [tip:x86/urgent] x86/unwind: Fix " tip-bot for Josh Poimboeuf
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