From: Alexander Potapenko <glider@google.com>
To: Andrey Konovalov <andreyknvl@google.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will.deacon@arm.com>,
Vincenzo Frascino <vincenzo.frascino@arm.com>,
Dmitry Vyukov <dvyukov@google.com>,
Andrey Ryabinin <aryabinin@virtuozzo.com>,
Marco Elver <elver@google.com>,
Evgenii Stepanov <eugenis@google.com>,
Branislav Rankov <Branislav.Rankov@arm.com>,
Kevin Brodsky <kevin.brodsky@arm.com>,
kasan-dev <kasan-dev@googlegroups.com>,
Linux ARM <linux-arm-kernel@lists.infradead.org>,
Linux Memory Management List <linux-mm@kvack.org>,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH mm v10 31/42] kasan, mm: untag page address in free_reserved_area
Date: Wed, 18 Nov 2020 17:07:45 +0100 [thread overview]
Message-ID: <CAG_fn=Xc_OOtqE5Q-fFejBBCfLGtc_kOmZAuE1wdTsjCOmpQ4Q@mail.gmail.com> (raw)
In-Reply-To: <b167fd21b86e7d728ba3a8e20be4f7e8373bc22c.1605305705.git.andreyknvl@google.com>
On Fri, Nov 13, 2020 at 11:17 PM Andrey Konovalov <andreyknvl@google.com> wrote:
>
> From: Vincenzo Frascino <vincenzo.frascino@arm.com>
>
> free_reserved_area() memsets the pages belonging to a given memory area.
> As that memory hasn't been allocated via page_alloc, the KASAN tags that
> those pages have are 0x00. As the result the memset might result in a tag
> mismatch.
>
> Untag the address to avoid spurious faults.
>
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
> Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
> ---
> Change-Id: If12b4944383575b8bbd7d971decbd7f04be6748b
> ---
> mm/page_alloc.c | 5 +++++
> 1 file changed, 5 insertions(+)
>
> diff --git a/mm/page_alloc.c b/mm/page_alloc.c
> index 855627e52f81..4a69fef13ac7 100644
> --- a/mm/page_alloc.c
> +++ b/mm/page_alloc.c
> @@ -7653,6 +7653,11 @@ unsigned long free_reserved_area(void *start, void *end, int poison, const char
> * alias for the memset().
> */
> direct_map_addr = page_address(page);
> + /*
> + * Perform a kasan-unchecked memset() since this memory
> + * has not been initialized.
> + */
> + direct_map_addr = kasan_reset_tag(direct_map_addr);
> if ((unsigned int)poison <= 0xFF)
> memset(direct_map_addr, poison, PAGE_SIZE);
>
> --
> 2.29.2.299.gdc1121823c-goog
>
--
Alexander Potapenko
Software Engineer
Google Germany GmbH
Erika-Mann-Straße, 33
80636 München
Geschäftsführer: Paul Manicle, Halimah DeLaine Prado
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Sitz der Gesellschaft: Hamburg
next prev parent reply other threads:[~2020-11-18 16:08 UTC|newest]
Thread overview: 53+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-13 22:15 [PATCH mm v10 00/42] kasan: add hardware tag-based mode for arm64 Andrey Konovalov
2020-11-13 22:15 ` [PATCH mm v10 01/42] kasan: drop unnecessary GPL text from comment headers Andrey Konovalov
2020-11-13 22:15 ` [PATCH mm v10 02/42] kasan: KASAN_VMALLOC depends on KASAN_GENERIC Andrey Konovalov
2020-11-13 22:15 ` [PATCH mm v10 03/42] kasan: group vmalloc code Andrey Konovalov
2020-11-13 22:15 ` [PATCH mm v10 04/42] kasan: shadow declarations only for software modes Andrey Konovalov
2020-11-13 22:15 ` [PATCH mm v10 05/42] kasan: rename (un)poison_shadow to (un)poison_range Andrey Konovalov
2020-11-18 15:30 ` Alexander Potapenko
2020-11-13 22:15 ` [PATCH mm v10 06/42] kasan: rename KASAN_SHADOW_* to KASAN_GRANULE_* Andrey Konovalov
2020-11-13 22:15 ` [PATCH mm v10 07/42] kasan: only build init.c for software modes Andrey Konovalov
2020-11-13 22:15 ` [PATCH mm v10 08/42] kasan: split out shadow.c from common.c Andrey Konovalov
2020-11-13 22:15 ` [PATCH mm v10 09/42] kasan: define KASAN_MEMORY_PER_SHADOW_PAGE Andrey Konovalov
2020-11-18 15:36 ` Alexander Potapenko
2020-11-13 22:15 ` [PATCH mm v10 10/42] kasan: rename report and tags files Andrey Konovalov
2020-11-13 22:15 ` [PATCH mm v10 11/42] kasan: don't duplicate config dependencies Andrey Konovalov
2020-11-13 22:15 ` [PATCH mm v10 12/42] kasan: hide invalid free check implementation Andrey Konovalov
2020-11-13 22:15 ` [PATCH mm v10 13/42] kasan: decode stack frame only with KASAN_STACK_ENABLE Andrey Konovalov
2020-11-13 22:15 ` [PATCH mm v10 14/42] kasan, arm64: only init shadow for software modes Andrey Konovalov
2020-11-13 22:15 ` [PATCH mm v10 15/42] kasan, arm64: only use kasan_depth " Andrey Konovalov
2020-11-13 22:15 ` [PATCH mm v10 16/42] kasan, arm64: move initialization message Andrey Konovalov
2020-11-13 22:15 ` [PATCH mm v10 17/42] kasan, arm64: rename kasan_init_tags and mark as __init Andrey Konovalov
2020-11-13 22:15 ` [PATCH mm v10 18/42] kasan: rename addr_has_shadow to addr_has_metadata Andrey Konovalov
2020-11-13 22:15 ` [PATCH mm v10 19/42] kasan: rename print_shadow_for_address to print_memory_metadata Andrey Konovalov
2020-11-13 22:15 ` [PATCH mm v10 20/42] kasan: rename SHADOW layout macros to META Andrey Konovalov
2020-11-13 22:15 ` [PATCH mm v10 21/42] kasan: separate metadata_fetch_row for each mode Andrey Konovalov
2020-11-13 22:15 ` [PATCH mm v10 22/42] kasan, arm64: don't allow SW_TAGS with ARM64_MTE Andrey Konovalov
2020-11-13 22:15 ` [PATCH mm v10 23/42] kasan: introduce CONFIG_KASAN_HW_TAGS Andrey Konovalov
2020-11-18 16:04 ` Alexander Potapenko
2020-11-13 22:15 ` [PATCH mm v10 24/42] arm64: Enable armv8.5-a asm-arch option Andrey Konovalov
2020-11-18 15:48 ` Alexander Potapenko
2020-11-13 22:15 ` [PATCH mm v10 25/42] arm64: mte: Add in-kernel MTE helpers Andrey Konovalov
2020-11-13 22:15 ` [PATCH mm v10 26/42] arm64: mte: Reset the page tag in page->flags Andrey Konovalov
2020-11-14 12:43 ` Catalin Marinas
2020-11-13 22:15 ` [PATCH mm v10 27/42] arm64: mte: Add in-kernel tag fault handler Andrey Konovalov
2020-11-13 22:15 ` [PATCH mm v10 28/42] arm64: kasan: Allow enabling in-kernel MTE Andrey Konovalov
2020-11-14 12:47 ` Catalin Marinas
2020-11-13 22:15 ` [PATCH mm v10 29/42] arm64: mte: Convert gcr_user into an exclude mask Andrey Konovalov
2020-11-13 22:15 ` [PATCH mm v10 30/42] arm64: mte: Switch GCR_EL1 in kernel entry and exit Andrey Konovalov
2020-11-13 22:15 ` [PATCH mm v10 31/42] kasan, mm: untag page address in free_reserved_area Andrey Konovalov
2020-11-18 16:07 ` Alexander Potapenko [this message]
2020-11-13 22:16 ` [PATCH mm v10 32/42] arm64: kasan: Align allocations for HW_TAGS Andrey Konovalov
2020-11-13 22:16 ` [PATCH mm v10 33/42] arm64: kasan: Add arch layer for memory tagging helpers Andrey Konovalov
2020-11-13 22:16 ` [PATCH mm v10 34/42] kasan: define KASAN_GRANULE_SIZE for HW_TAGS Andrey Konovalov
2020-11-13 22:16 ` [PATCH mm v10 35/42] kasan, x86, s390: update undef CONFIG_KASAN Andrey Konovalov
2020-11-13 22:16 ` [PATCH mm v10 36/42] kasan, arm64: expand CONFIG_KASAN checks Andrey Konovalov
2020-11-13 22:16 ` [PATCH mm v10 37/42] kasan, arm64: implement HW_TAGS runtime Andrey Konovalov
2020-11-13 22:16 ` [PATCH mm v10 38/42] kasan, arm64: print report from tag fault handler Andrey Konovalov
2020-11-13 22:16 ` [PATCH mm v10 39/42] kasan, mm: reset tags when accessing metadata Andrey Konovalov
2020-11-13 22:16 ` [PATCH mm v10 40/42] kasan, arm64: enable CONFIG_KASAN_HW_TAGS Andrey Konovalov
2020-11-13 22:16 ` [PATCH mm v10 41/42] kasan: add documentation for hardware tag-based mode Andrey Konovalov
2020-11-18 15:43 ` Alexander Potapenko
2020-11-13 22:16 ` [PATCH mm v10 42/42] kselftest/arm64: Check GCR_EL1 after context switch Andrey Konovalov
2020-11-13 23:35 ` [PATCH mm v10 00/42] kasan: add hardware tag-based mode for arm64 Andrew Morton
2020-11-16 14:48 ` Vincenzo Frascino
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