kasan, slab: fix conflicts with CONFIG_HARDENED_USERCOPY

Similarly to commit 96fedce27e ("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.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Tested-by: Qian Cai <cai@lca.pw>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgeniy Stepanov <eugenis@google.com>
Cc: Kostya Serebryany <kcc@google.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Andrey Konovalov 2019-02-20 22:20:25 -08:00 committed by Linus Torvalds
parent dc15a8a254
commit 219667c23c
1 changed files with 2 additions and 0 deletions

View File

@ -4408,6 +4408,8 @@ 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);