From: Andrey Konovalov <andreyk...@google.com>
[ Upstream commit 219667c23c68eb3dbc0d5662b9246f28477fe529 ]
Similarly to commit 96fedce27e13 ("kasan: make tag based mode work with
CONFIG_HARDENED_USERCOPY"), we need to reset pointer tags in
__check_heap_object() in mm/slab.c before doing any pointer math.
Link:
http://lkml.kernel.org/r/9a5c0f958db10e69df5ff9f2b997866b56b7effc.1550602886.git.andreyk...@google.com
Signed-off-by: Andrey Konovalov <andreyk...@google.com>
Tested-by: Qian Cai <c...@lca.pw>
Cc: Alexander Potapenko <gli...@google.com>
Cc: Andrey Ryabinin <aryabi...@virtuozzo.com>
Cc: Catalin Marinas <catalin.mari...@arm.com>
Cc: Dmitry Vyukov <dvyu...@google.com>
Cc: Evgeniy Stepanov <euge...@google.com>
Cc: Kostya Serebryany <k...@google.com>
Cc: Vincenzo Frascino <vincenzo.frasc...@arm.com>
Signed-off-by: Andrew Morton <a...@linux-foundation.org>
Signed-off-by: Linus Torvalds <torva...@linux-foundation.org>
Signed-off-by: Sasha Levin <sas...@kernel.org>
---
mm/slab.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/mm/slab.c b/mm/slab.c
index 9d5de959d9d9..05f21f736be8 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -4421,6 +4421,8 @@ void __check_heap_object(const void *ptr, unsigned long
n, struct page *page,
unsigned int objnr;
unsigned long offset;
+ ptr = kasan_reset_tag(ptr);
+
/* Find and validate object. */
cachep = page->slab_cache;
objnr = obj_to_index(cachep, page, (void *)ptr);
--
2.19.1
