+ kasan-fix-conflict-with-page-poisoning.patch added to -mm tree

+ kasan-fix-conflict-with-page-poisoning.patch added to -mm tree

[akpm]

The patch titled
     Subject: kasan: fix conflict with page poisoning
has been added to the -mm tree.  Its filename is
     kasan-fix-conflict-with-page-poisoning.patch

This patch should soon appear at
    https://ozlabs.org/~akpm/mmots/broken-out/kasan-fix-conflict-with-page-poisoning.patch
and later at
    https://ozlabs.org/~akpm/mmotm/broken-out/kasan-fix-conflict-with-page-poisoning.patch

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*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***

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------------------------------------------------------
From: Andrey Konovalov <andreyknvl@google.com>
Subject: kasan: fix conflict with page poisoning

When page poisoning is enabled, it accesses memory that is marked as
poisoned by KASAN, which leas to false-positive KASAN reports.

Suppress the reports by adding KASAN annotations to unpoison_page()
(poison_page() already has them).

Link: https://lkml.kernel.org/r/2dc799014d31ac13fd97bd906bad33e16376fc67.1617118501.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Marco Elver <elver@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/page_poison.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

--- a/mm/page_poison.c~kasan-fix-conflict-with-page-poisoning
+++ a/mm/page_poison.c
@@ -77,12 +77,14 @@ static void unpoison_page(struct page *p
 	void *addr;
 
 	addr = kmap_atomic(page);
+	kasan_disable_current();
 	/*
 	 * Page poisoning when enabled poisons each and every page
 	 * that is freed to buddy. Thus no extra check is done to
 	 * see if a page was poisoned.
 	 */
-	check_poison_mem(addr, PAGE_SIZE);
+	check_poison_mem(kasan_reset_tag(addr), PAGE_SIZE);
+	kasan_enable_current();
 	kunmap_atomic(addr);
 }
 
_

Patches currently in -mm which might be from andreyknvl@google.com are

kasan-fix-conflict-with-page-poisoning.patch
kasan-initialize-shadow-to-tag_invalid-for-sw_tags.patch
mm-kasan-dont-poison-boot-memory-with-tag-based-modes.patch
arm64-kasan-allow-to-init-memory-when-setting-tags.patch
kasan-init-memory-in-kasan_unpoison-for-hw_tags.patch
kasan-mm-integrate-page_alloc-init-with-hw_tags.patch
kasan-mm-integrate-page_alloc-init-with-hw_tags-fix.patch
kasan-mm-integrate-slab-init_on_alloc-with-hw_tags.patch
kasan-mm-integrate-slab-init_on_free-with-hw_tags.patch
kasan-docs-clean-up-sections.patch
kasan-docs-update-overview-section.patch
kasan-docs-update-usage-section.patch
kasan-docs-update-error-reports-section.patch
kasan-docs-update-boot-parameters-section.patch
kasan-docs-update-generic-implementation-details-section.patch
kasan-docs-update-sw_tags-implementation-details-section.patch
kasan-docs-update-hw_tags-implementation-details-section.patch
kasan-docs-update-shadow-memory-section.patch
kasan-docs-update-ignoring-accesses-section.patch
kasan-docs-update-tests-section.patch