From: Dmitry Vyukov <dvyukov@google.com>
To: Marco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>,
Andrew Morton <akpm@linux-foundation.org>,
Catalin Marinas <catalin.marinas@arm.com>,
Christoph Lameter <cl@linux.com>,
David Rientjes <rientjes@google.com>,
Joonsoo Kim <iamjoonsoo.kim@lge.com>,
Mark Rutland <mark.rutland@arm.com>,
Pekka Enberg <penberg@kernel.org>,
"H. Peter Anvin" <hpa@zytor.com>,
"Paul E. McKenney" <paulmck@kernel.org>,
Andrey Konovalov <andreyknvl@google.com>,
Andrey Ryabinin <aryabinin@virtuozzo.com>,
Andy Lutomirski <luto@kernel.org>,
Borislav Petkov <bp@alien8.de>,
Dave Hansen <dave.hansen@linux.intel.com>,
Eric Dumazet <edumazet@google.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Ingo Molnar <mingo@redhat.com>, Jann Horn <jannh@google.com>,
Jonathan Corbet <corbet@lwn.net>,
Kees Cook <keescook@chromium.org>,
Peter Zijlstra <peterz@infradead.org>, Qian Cai <cai@lca.pw>,
Thomas Gleixner <tglx@linutronix.de>,
Will Deacon <will@kernel.org>,
"the arch/x86 maintainers" <x86@kernel.org>,
"open list:DOCUMENTATION" <linux-doc@vger.kernel.org>,
LKML <linux-kernel@vger.kernel.org>,
kasan-dev <kasan-dev@googlegroups.com>,
Linux ARM <linux-arm-kernel@lists.infradead.org>,
Linux-MM <linux-mm@kvack.org>
Subject: Re: [PATCH RFC 06/10] kfence, kasan: make KFENCE compatible with KASAN
Date: Fri, 11 Sep 2020 09:04:54 +0200 [thread overview]
Message-ID: <CACT4Y+b=Ph-fD_K5F_TNMp_dTNjD7GXGT=OXogrKc_HwH+HHwQ@mail.gmail.com> (raw)
In-Reply-To: <20200907134055.2878499-7-elver@google.com>
On Mon, Sep 7, 2020 at 3:41 PM Marco Elver <elver@google.com> wrote:
>
> From: Alexander Potapenko <glider@google.com>
>
> We make KFENCE compatible with KASAN for testing KFENCE itself. In
> particular, KASAN helps to catch any potential corruptions to KFENCE
> state, or other corruptions that may be a result of freepointer
> corruptions in the main allocators.
>
> To indicate that the combination of the two is generally discouraged,
> CONFIG_EXPERT=y should be set. It also gives us the nice property that
> KFENCE will be build-tested by allyesconfig builds.
>
> Co-developed-by: Marco Elver <elver@google.com>
> Signed-off-by: Marco Elver <elver@google.com>
> Signed-off-by: Alexander Potapenko <glider@google.com>
> ---
> lib/Kconfig.kfence | 2 +-
> mm/kasan/common.c | 7 +++++++
> 2 files changed, 8 insertions(+), 1 deletion(-)
>
> diff --git a/lib/Kconfig.kfence b/lib/Kconfig.kfence
> index 7ac91162edb0..b080e49e15d4 100644
> --- a/lib/Kconfig.kfence
> +++ b/lib/Kconfig.kfence
> @@ -10,7 +10,7 @@ config HAVE_ARCH_KFENCE_STATIC_POOL
>
> menuconfig KFENCE
> bool "KFENCE: low-overhead sampling-based memory safety error detector"
> - depends on HAVE_ARCH_KFENCE && !KASAN && (SLAB || SLUB)
> + depends on HAVE_ARCH_KFENCE && (!KASAN || EXPERT) && (SLAB || SLUB)
> depends on JUMP_LABEL # To ensure performance, require jump labels
> select STACKTRACE
> help
> diff --git a/mm/kasan/common.c b/mm/kasan/common.c
> index 950fd372a07e..f5c49f0fdeff 100644
> --- a/mm/kasan/common.c
> +++ b/mm/kasan/common.c
> @@ -18,6 +18,7 @@
> #include <linux/init.h>
> #include <linux/kasan.h>
> #include <linux/kernel.h>
> +#include <linux/kfence.h>
> #include <linux/kmemleak.h>
> #include <linux/linkage.h>
> #include <linux/memblock.h>
> @@ -396,6 +397,9 @@ static bool __kasan_slab_free(struct kmem_cache *cache, void *object,
> tagged_object = object;
> object = reset_tag(object);
>
> + if (is_kfence_address(object))
> + return false;
Is this needed?
At least in the slab patch I see that we do :
if (kfence_free(objp)) {
kmemleak_free_recursive(objp, cachep->flags);
return;
}
before:
/* Put the object into the quarantine, don't touch it for now. */ /*
Put the object into the quarantine, don't touch it for now. */
if (kasan_slab_free(cachep, objp, _RET_IP_)) if
(kasan_slab_free(cachep, objp, _RET_IP_))
return; return;
If it's not supposed to be triggered, it can make sense to replace
with BUG/WARN.
> if (unlikely(nearest_obj(cache, virt_to_head_page(object), object) !=
> object)) {
> kasan_report_invalid_free(tagged_object, ip);
> @@ -444,6 +448,9 @@ static void *__kasan_kmalloc(struct kmem_cache *cache, const void *object,
> if (unlikely(object == NULL))
> return NULL;
>
> + if (is_kfence_address(object))
> + return (void *)object;
> +
> redzone_start = round_up((unsigned long)(object + size),
> KASAN_SHADOW_SCALE_SIZE);
> redzone_end = round_up((unsigned long)object + cache->object_size,
> --
> 2.28.0.526.ge36021eeef-goog
>
next prev parent reply other threads:[~2020-09-11 7:05 UTC|newest]
Thread overview: 55+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-07 13:40 [PATCH RFC 00/10] KFENCE: A low-overhead sampling-based memory safety error detector Marco Elver
2020-09-07 13:40 ` [PATCH RFC 01/10] mm: add Kernel Electric-Fence infrastructure Marco Elver
2020-09-07 15:41 ` Jonathan Cameron
2020-09-07 16:38 ` Marco Elver
2020-09-10 14:57 ` Dmitry Vyukov
2020-09-10 15:06 ` Marco Elver
2020-09-10 15:48 ` Dmitry Vyukov
2020-09-10 16:22 ` Marco Elver
2020-09-10 15:42 ` Dmitry Vyukov
2020-09-10 16:19 ` Alexander Potapenko
2020-09-10 17:11 ` Dmitry Vyukov
2020-09-10 17:41 ` Marco Elver
2020-09-10 20:25 ` Paul E. McKenney
2020-09-15 13:57 ` SeongJae Park
2020-09-15 14:14 ` Marco Elver
2020-09-15 14:26 ` SeongJae Park
2020-09-07 13:40 ` [PATCH RFC 02/10] x86, kfence: enable KFENCE for x86 Marco Elver
2020-09-07 13:40 ` [PATCH RFC 03/10] arm64, kfence: enable KFENCE for ARM64 Marco Elver
2020-09-09 15:13 ` Marco Elver
2020-09-07 13:40 ` [PATCH RFC 04/10] mm, kfence: insert KFENCE hooks for SLAB Marco Elver
2020-09-11 7:17 ` Dmitry Vyukov
2020-09-11 12:24 ` Marco Elver
2020-09-11 13:03 ` Dmitry Vyukov
2020-09-07 13:40 ` [PATCH RFC 05/10] mm, kfence: insert KFENCE hooks for SLUB Marco Elver
2020-09-07 13:40 ` [PATCH RFC 06/10] kfence, kasan: make KFENCE compatible with KASAN Marco Elver
2020-09-11 7:04 ` Dmitry Vyukov [this message]
2020-09-11 13:00 ` Marco Elver
2020-09-07 13:40 ` [PATCH RFC 07/10] kfence, kmemleak: make KFENCE compatible with KMEMLEAK Marco Elver
2020-09-08 11:53 ` Catalin Marinas
2020-09-08 12:29 ` Alexander Potapenko
2020-09-07 13:40 ` [PATCH RFC 08/10] kfence, lockdep: make KFENCE compatible with lockdep Marco Elver
2020-09-07 13:40 ` [PATCH RFC 09/10] kfence, Documentation: add KFENCE documentation Marco Elver
2020-09-07 15:33 ` Andrey Konovalov
2020-09-07 16:33 ` Marco Elver
2020-09-07 17:55 ` Andrey Konovalov
2020-09-07 18:16 ` Marco Elver
2020-09-08 15:54 ` Dave Hansen
2020-09-08 16:14 ` Marco Elver
2020-09-11 7:14 ` Dmitry Vyukov
2020-09-11 7:46 ` Marco Elver
2020-09-07 13:40 ` [PATCH RFC 10/10] kfence: add test suite Marco Elver
2020-09-08 11:48 ` [PATCH RFC 00/10] KFENCE: A low-overhead sampling-based memory safety error detector Vlastimil Babka
2020-09-08 12:16 ` Alexander Potapenko
2020-09-08 14:40 ` Vlastimil Babka
2020-09-08 15:21 ` Marco Elver
2020-09-08 14:52 ` Dave Hansen
2020-09-08 15:31 ` Marco Elver
2020-09-08 15:36 ` Vlastimil Babka
2020-09-08 15:56 ` Marco Elver
2020-09-11 7:35 ` Dmitry Vyukov
2020-09-11 12:03 ` Marco Elver
2020-09-11 13:09 ` Dmitry Vyukov
2020-09-11 13:33 ` Marco Elver
2020-09-11 16:33 ` Marco Elver
2020-09-08 15:37 ` Dave Hansen
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