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author | Andrey Konovalov <andreyknvl@google.com> | 2020-12-22 12:00:46 -0800 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-12-22 12:55:07 -0800 |
commit | 2cdbed63490d0d2bcbae60abcc5639caa5aba49b (patch) | |
tree | 8eb9b73b331c54dd6f5d359ccf9acc5acdbb408d /mm/kasan/common.c | |
parent | ffcc5cea46c0c3dde4eeb101fdf3a37da43863de (diff) | |
download | linux-2cdbed63490d0d2bcbae60abcc5639caa5aba49b.tar.gz linux-2cdbed63490d0d2bcbae60abcc5639caa5aba49b.tar.bz2 linux-2cdbed63490d0d2bcbae60abcc5639caa5aba49b.zip |
kasan: hide invalid free check implementation
This is a preparatory commit for the upcoming addition of a new hardware
tag-based (MTE-based) KASAN mode.
For software KASAN modes the check is based on the value in the shadow
memory. Hardware tag-based KASAN won't be using shadow, so hide the
implementation of the check in check_invalid_free().
Also simplify the code for software tag-based mode.
No functional changes for software modes.
Link: https://lkml.kernel.org/r/d01534a4b977f97d87515dc590e6348e1406de81.1606161801.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Marco Elver <elver@google.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/kasan/common.c')
-rw-r--r-- | mm/kasan/common.c | 19 |
1 files changed, 1 insertions, 18 deletions
diff --git a/mm/kasan/common.c b/mm/kasan/common.c index 88f57346c7bd..663ffa71cd20 100644 --- a/mm/kasan/common.c +++ b/mm/kasan/common.c @@ -277,25 +277,9 @@ void * __must_check kasan_init_slab_obj(struct kmem_cache *cache, return (void *)object; } -static inline bool shadow_invalid(u8 tag, s8 shadow_byte) -{ - if (IS_ENABLED(CONFIG_KASAN_GENERIC)) - return shadow_byte < 0 || - shadow_byte >= KASAN_GRANULE_SIZE; - - /* else CONFIG_KASAN_SW_TAGS: */ - if ((u8)shadow_byte == KASAN_TAG_INVALID) - return true; - if ((tag != KASAN_TAG_KERNEL) && (tag != (u8)shadow_byte)) - return true; - - return false; -} - static bool __kasan_slab_free(struct kmem_cache *cache, void *object, unsigned long ip, bool quarantine) { - s8 shadow_byte; u8 tag; void *tagged_object; unsigned long rounded_up_size; @@ -314,8 +298,7 @@ static bool __kasan_slab_free(struct kmem_cache *cache, void *object, if (unlikely(cache->flags & SLAB_TYPESAFE_BY_RCU)) return false; - shadow_byte = READ_ONCE(*(s8 *)kasan_mem_to_shadow(object)); - if (shadow_invalid(tag, shadow_byte)) { + if (check_invalid_free(tagged_object)) { kasan_report_invalid_free(tagged_object, ip); return true; } |