From: Andrew Morton <akpm@linux-foundation.org>
To: akpm@linux-foundation.org, andreyknvl@google.com,
aryabinin@virtuozzo.com, Branislav.Rankov@arm.com,
catalin.marinas@arm.com, dvyukov@google.com, elver@google.com,
eugenis@google.com, glider@google.com, kevin.brodsky@arm.com,
linux-mm@kvack.org, mm-commits@vger.kernel.org, pcc@google.com,
torvalds@linux-foundation.org, vincenzo.frascino@arm.com,
will.deacon@arm.com
Subject: [patch 11/19] kasan, mm: fix resetting page_alloc tags for HW_TAGS
Date: Sat, 23 Jan 2021 21:01:43 -0800 [thread overview]
Message-ID: <20210124050143.UF-3I8lr9%akpm@linux-foundation.org> (raw)
In-Reply-To: <20210123210029.a7c704d0cab204683e41ad10@linux-foundation.org>
From: Andrey Konovalov <andreyknvl@google.com>
Subject: kasan, mm: fix resetting page_alloc tags for HW_TAGS
A previous commit added resetting KASAN page tags to
kernel_init_free_pages() to avoid false-positives due to accesses to
metadata with the hardware tag-based mode.
That commit did reset page tags before the metadata access, but didn't
restore them after. As the result, KASAN fails to detect bad accesses to
page_alloc allocations on some configurations.
Fix this by recovering the tag after the metadata access.
Link: https://lkml.kernel.org/r/02b5bcd692e912c27d484030f666b350ad7e4ae4.1611074450.git.andreyknvl@google.com
Fixes: aa1ef4d7b3f6 ("kasan, mm: reset tags when accessing metadata")
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Marco Elver <elver@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Peter Collingbourne <pcc@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
mm/page_alloc.c | 2 ++
1 file changed, 2 insertions(+)
--- a/mm/page_alloc.c~kasan-mm-fix-resetting-page_alloc-tags-for-hw_tags
+++ a/mm/page_alloc.c
@@ -1207,8 +1207,10 @@ static void kernel_init_free_pages(struc
/* s390's use of memset() could override KASAN redzones. */
kasan_disable_current();
for (i = 0; i < numpages; i++) {
+ u8 tag = page_kasan_tag(page + i);
page_kasan_tag_reset(page + i);
clear_highpage(page + i);
+ page_kasan_tag_set(page + i, tag);
}
kasan_enable_current();
}
_
next prev parent reply other threads:[~2021-01-24 5:02 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-24 5:00 incoming Andrew Morton
2021-01-24 5:00 ` [patch 01/19] x86/setup: don't remove E820_TYPE_RAM for pfn 0 Andrew Morton
2021-01-24 5:01 ` [patch 02/19] mm: fix initialization of struct page for holes in memory layout Andrew Morton
2021-01-24 5:01 ` [patch 03/19] mm: memcg/slab: optimize objcg stock draining Andrew Morton
2021-01-24 5:01 ` [patch 04/19] mm: memcg: fix memcg file_dirty numa stat Andrew Morton
2021-01-24 5:01 ` [patch 05/19] mm: fix numa stats for thp migration Andrew Morton
2021-01-24 5:01 ` [patch 06/19] mm: memcontrol: prevent starvation when writing memory.high Andrew Morton
2021-01-24 18:01 ` Shakeel Butt
2021-01-24 18:35 ` Linus Torvalds
2021-01-24 5:01 ` [patch 07/19] kasan: fix unaligned address is unhandled in kasan_remove_zero_shadow Andrew Morton
2021-01-24 5:01 ` [patch 08/19] kasan: fix incorrect arguments passing in kasan_add_zero_shadow Andrew Morton
2021-01-24 5:01 ` [patch 09/19] kasan: fix HW_TAGS boot parameters Andrew Morton
2021-01-24 5:01 ` [patch 10/19] kasan, mm: fix conflicts with init_on_alloc/free Andrew Morton
2021-01-24 5:01 ` Andrew Morton [this message]
2021-01-24 5:01 ` [patch 12/19] ubsan: disable unsigned-overflow check for i386 Andrew Morton
2021-01-24 5:01 ` [patch 13/19] mm: fix page reference leak in soft_offline_page() Andrew Morton
2021-01-24 5:01 ` [patch 14/19] sparc/mm/highmem: flush cache and TLB Andrew Morton
2021-01-24 5:02 ` [patch 15/19] mm/highmem: prepare for overriding set_pte_at() Andrew Morton
2021-01-24 5:02 ` [patch 16/19] mips/mm/highmem: use set_pte() for kmap_local() Andrew Morton
2021-01-24 5:02 ` [patch 17/19] powerpc/mm/highmem: use __set_pte_at() " Andrew Morton
2021-01-24 5:02 ` [patch 18/19] proc_sysctl: fix oops caused by incorrect command parameters Andrew Morton
2021-01-24 5:02 ` [patch 19/19] MAINTAINERS: add a couple more files to the Clang/LLVM section Andrew Morton
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