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authorAndrey Konovalov <andreyknvl@google.com>2021-04-09 13:27:38 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2021-04-09 14:54:23 -0700
commit06b1f85588948bd4c772845e5d6891b8f6082248 (patch)
treecfe4931b5eaa039a84cee63bb271ce21c1eb5b87
parentdf41872b68601059dd4a84858952dcae58acd331 (diff)
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> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--mm/page_poison.c4
1 files changed, 3 insertions, 1 deletions
diff --git a/mm/page_poison.c b/mm/page_poison.c
index 65cdf844c8ad..655dc5895604 100644
--- a/mm/page_poison.c
+++ b/mm/page_poison.c
@@ -77,12 +77,14 @@ static void unpoison_page(struct page *page)
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);
}