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From: Marco Elver <elver@google.com>
To: Pekka Enberg <penberg@gmail.com>
Cc: Alexander Potapenko <glider@google.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	David Rientjes <rientjes@google.com>,
	Joonsoo Kim <iamjoonsoo.kim@lge.com>,
	Christoph Lameter <cl@linux.com>,
	Kees Cook <keescook@chromium.org>,
	kasan-dev <kasan-dev@googlegroups.com>,
	LKML <linux-kernel@vger.kernel.org>,
	"linux-mm@kvack.org" <linux-mm@kvack.org>
Subject: Re: Odd-sized kmem_cache_alloc and slub_debug=Z
Date: Mon, 17 Aug 2020 20:31:35 +0200	[thread overview]
Message-ID: <CANpmjNNhG4VuGq2_kocsTD3CnCv-Y4Kvnz7_VuvZ9Eug+-T=Eg@mail.gmail.com> (raw)
In-Reply-To: <CAOJsxLEJtXdCNtouqNTFxYtm5j_nnFQHpMfTOsUL2+WrLbR39g@mail.gmail.com>

On Fri, 7 Aug 2020 at 21:06, Pekka Enberg <penberg@gmail.com> wrote:
...
> Yeah, it reproduces with defconfig too, as long as you remember to
> pass "slub_debug=Z"... :-/
>
> The following seems to be the culprit:
>
> commit 3202fa62fb43087387c65bfa9c100feffac74aa6
> Author: Kees Cook <keescook@chromium.org>
> Date:   Wed Apr 1 21:04:27 2020 -0700
>
>     slub: relocate freelist pointer to middle of object
>
> Reverting this commit and one of it's follow up fixes from Kees from
> v5.8 makes the issue go away for me. Btw, please note that caches with
> size 24 and larger do not trigger this bug, so the issue is that with
> small enough object size, we're stomping on allocator metadata (I
> assume part of the freelist).

Was there a patch to fix this? Checking, just in case I missed it.

Thanks,
-- Marco

  reply	other threads:[~2020-08-17 18:32 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-08-07 16:06 Odd-sized kmem_cache_alloc and slub_debug=Z Marco Elver
2020-08-07 17:06 ` Pekka Enberg
2020-08-07 17:18   ` Marco Elver
2020-08-07 19:06     ` Pekka Enberg
2020-08-17 18:31       ` Marco Elver [this message]
2020-10-08 23:10         ` Kees Cook
2020-08-07 17:16 ` Kees Cook
2020-08-07 17:20   ` Marco Elver

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