The patch titled
Subject: kasan: make tag based mode work with CONFIG_HARDENED_USERCOPY
has been added to the -mm tree. Its filename is
kasan-make-tag-based-mode-work-with-config_hardened_usercopy.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/kasan-make-tag-based-mode-work-with-config_hardened_usercopy.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/kasan-make-tag-based-mode-work-with-config_hardened_usercopy.patch
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------------------------------------------------------
From: Andrey Konovalov <andreyknvl@xxxxxxxxxx>
Subject: kasan: make tag based mode work with CONFIG_HARDENED_USERCOPY
With CONFIG_HARDENED_USERCOPY enabled __check_heap_object() compares and
then subtracts a potentially tagged pointer with a non-tagged address of
the page that this pointer belongs to, which leads to unexpected behavior.
Untag the pointer in __check_heap_object() before doing any of these
operations.
Link: http://lkml.kernel.org/r/7e756a298d514c4482f52aea6151db34818d395d.1546540962.git.andreyknvl@xxxxxxxxxx
Signed-off-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx>
Cc: Andrey Ryabinin <aryabinin@xxxxxxxxxxxxx>
Cc: Christoph Lameter <cl@xxxxxxxxx>
Cc: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
Cc: Mark Rutland <mark.rutland@xxxxxxx>
Cc: Vincenzo Frascino <vincenzo.frascino@xxxxxxx>
Cc: Will Deacon <will.deacon@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/slub.c | 2 ++
1 file changed, 2 insertions(+)
--- a/mm/slub.c~kasan-make-tag-based-mode-work-with-config_hardened_usercopy
+++ a/mm/slub.c
@@ -3846,6 +3846,8 @@ void __check_heap_object(const void *ptr
unsigned int offset;
size_t object_size;
+ ptr = kasan_reset_tag(ptr);
+
/* Find object and usable object size. */
s = page->slab_cache;
_
Patches currently in -mm which might be from andreyknvl@xxxxxxxxxx are
kasan-arm64-use-arch_slab_minalign-instead-of-manual-aligning.patch
kasan-make-tag-based-mode-work-with-config_hardened_usercopy.patch
kasan-fix-krealloc-handling-for-tag-based-mode.patch
