From: Andrey Konovalov <andreyknvl@google.com>
To: Dmitry Vyukov <dvyukov@google.com>,
Vincenzo Frascino <vincenzo.frascino@arm.com>,
Catalin Marinas <catalin.marinas@arm.com>,
kasan-dev@googlegroups.com
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>,
Alexander Potapenko <glider@google.com>,
Marco Elver <elver@google.com>,
Evgenii Stepanov <eugenis@google.com>,
Elena Petrova <lenaptr@google.com>,
Branislav Rankov <Branislav.Rankov@arm.com>,
Kevin Brodsky <kevin.brodsky@arm.com>,
Will Deacon <will.deacon@arm.com>,
Andrew Morton <akpm@linux-foundation.org>,
linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org,
linux-kernel@vger.kernel.org,
Andrey Konovalov <andreyknvl@google.com>
Subject: [PATCH v4 12/39] kasan: hide invalid free check implementation
Date: Fri, 2 Oct 2020 01:10:13 +0200 [thread overview]
Message-ID: <823cf1ad36d0a93ed0ecdd81fab8c5b77437c418.1601593784.git.andreyknvl@google.com> (raw)
In-Reply-To: <cover.1601593784.git.andreyknvl@google.com>
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.
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Marco Elver <elver@google.com>
---
Change-Id: I5fae9531c9fc948eb4d4e0c589744032fc5a0789
---
mm/kasan/common.c | 19 +------------------
mm/kasan/generic.c | 7 +++++++
mm/kasan/kasan.h | 2 ++
mm/kasan/sw_tags.c | 9 +++++++++
4 files changed, 19 insertions(+), 18 deletions(-)
diff --git a/mm/kasan/common.c b/mm/kasan/common.c
index 123abfb760d4..543e6bf2168f 100644
--- a/mm/kasan/common.c
+++ b/mm/kasan/common.c
@@ -272,25 +272,9 @@ 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;
@@ -309,8 +293,7 @@ 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;
}
diff --git a/mm/kasan/generic.c b/mm/kasan/generic.c
index ec4417156943..e1af3b6c53b8 100644
--- a/mm/kasan/generic.c
+++ b/mm/kasan/generic.c
@@ -187,6 +187,13 @@ bool check_memory_region(unsigned long addr, size_t size, bool write,
return check_memory_region_inline(addr, size, write, ret_ip);
}
+bool check_invalid_free(void *addr)
+{
+ s8 shadow_byte = READ_ONCE(*(s8 *)kasan_mem_to_shadow(addr));
+
+ return shadow_byte < 0 || shadow_byte >= KASAN_GRANULE_SIZE;
+}
+
void kasan_cache_shrink(struct kmem_cache *cache)
{
quarantine_remove_cache(cache);
diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h
index 1865bb92d47a..3eff57e71ff5 100644
--- a/mm/kasan/kasan.h
+++ b/mm/kasan/kasan.h
@@ -164,6 +164,8 @@ void kasan_poison_memory(const void *address, size_t size, u8 value);
bool check_memory_region(unsigned long addr, size_t size, bool write,
unsigned long ret_ip);
+bool check_invalid_free(void *addr);
+
void *find_first_bad_addr(void *addr, size_t size);
const char *get_bug_type(struct kasan_access_info *info);
diff --git a/mm/kasan/sw_tags.c b/mm/kasan/sw_tags.c
index 4bdd7dbd6647..b2638c2cd58a 100644
--- a/mm/kasan/sw_tags.c
+++ b/mm/kasan/sw_tags.c
@@ -121,6 +121,15 @@ bool check_memory_region(unsigned long addr, size_t size, bool write,
return true;
}
+bool check_invalid_free(void *addr)
+{
+ u8 tag = get_tag(addr);
+ u8 shadow_byte = READ_ONCE(*(u8 *)kasan_mem_to_shadow(reset_tag(addr)));
+
+ return (shadow_byte == KASAN_TAG_INVALID) ||
+ (tag != KASAN_TAG_KERNEL && tag != shadow_byte);
+}
+
#define DEFINE_HWASAN_LOAD_STORE(size) \
void __hwasan_load##size##_noabort(unsigned long addr) \
{ \
--
2.28.0.709.gb0816b6eb0-goog
next prev parent reply other threads:[~2020-10-01 23:11 UTC|newest]
Thread overview: 49+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-01 23:10 [PATCH v4 00/39] kasan: add hardware tag-based mode for arm64 Andrey Konovalov
2020-10-01 23:10 ` [PATCH v4 01/39] kasan: drop unnecessary GPL text from comment headers Andrey Konovalov
2020-10-01 23:10 ` [PATCH v4 02/39] kasan: KASAN_VMALLOC depends on KASAN_GENERIC Andrey Konovalov
2020-10-01 23:10 ` [PATCH v4 03/39] kasan: group vmalloc code Andrey Konovalov
2020-10-01 23:10 ` [PATCH v4 04/39] kasan: shadow declarations only for software modes Andrey Konovalov
2020-10-01 23:10 ` [PATCH v4 05/39] kasan: rename (un)poison_shadow to (un)poison_memory Andrey Konovalov
2020-10-01 23:10 ` [PATCH v4 06/39] kasan: rename KASAN_SHADOW_* to KASAN_GRANULE_* Andrey Konovalov
2020-10-01 23:10 ` [PATCH v4 07/39] kasan: only build init.c for software modes Andrey Konovalov
2020-10-01 23:10 ` [PATCH v4 08/39] kasan: split out shadow.c from common.c Andrey Konovalov
2020-10-01 23:10 ` [PATCH v4 09/39] kasan: define KASAN_GRANULE_PAGE Andrey Konovalov
2020-10-01 23:10 ` [PATCH v4 10/39] kasan: rename report and tags files Andrey Konovalov
2020-10-01 23:10 ` [PATCH v4 11/39] kasan: don't duplicate config dependencies Andrey Konovalov
2020-10-01 23:10 ` Andrey Konovalov [this message]
2020-10-01 23:10 ` [PATCH v4 13/39] kasan: decode stack frame only with KASAN_STACK_ENABLE Andrey Konovalov
2020-10-01 23:10 ` [PATCH v4 14/39] kasan, arm64: only init shadow for software modes Andrey Konovalov
2020-10-01 23:10 ` [PATCH v4 15/39] kasan, arm64: only use kasan_depth " Andrey Konovalov
2020-10-01 23:10 ` [PATCH v4 16/39] kasan: rename addr_has_shadow to addr_has_metadata Andrey Konovalov
2020-10-01 23:10 ` [PATCH v4 17/39] kasan: rename print_shadow_for_address to print_memory_metadata Andrey Konovalov
2020-10-01 23:10 ` [PATCH v4 18/39] kasan: kasan_non_canonical_hook only for software modes Andrey Konovalov
2020-10-01 23:10 ` [PATCH v4 19/39] kasan: rename SHADOW layout macros to META Andrey Konovalov
2020-10-01 23:10 ` [PATCH v4 20/39] kasan: separate metadata_fetch_row for each mode Andrey Konovalov
2020-10-01 23:10 ` [PATCH v4 21/39] kasan, arm64: don't allow SW_TAGS with ARM64_MTE Andrey Konovalov
2020-10-01 23:10 ` [PATCH v4 22/39] kasan: introduce CONFIG_KASAN_HW_TAGS Andrey Konovalov
2020-10-01 23:10 ` [PATCH v4 23/39] arm64: Enable armv8.5-a asm-arch option Andrey Konovalov
2020-10-01 23:10 ` [PATCH v4 24/39] arm64: mte: Add in-kernel MTE helpers Andrey Konovalov
2020-10-02 13:51 ` Catalin Marinas
2020-10-01 23:10 ` [PATCH v4 25/39] arm64: kasan: Add arch layer for memory tagging helpers Andrey Konovalov
2020-10-01 23:10 ` [PATCH v4 26/39] arm64: mte: Add in-kernel tag fault handler Andrey Konovalov
2020-10-01 23:10 ` [PATCH v4 27/39] arm64: kasan: Enable in-kernel MTE Andrey Konovalov
2020-10-02 14:00 ` Catalin Marinas
2020-10-01 23:10 ` [PATCH v4 28/39] arm64: mte: Convert gcr_user into an exclude mask Andrey Konovalov
2020-10-01 23:10 ` [PATCH v4 29/39] arm64: mte: Switch GCR_EL1 in kernel entry and exit Andrey Konovalov
2020-10-02 14:06 ` Catalin Marinas
2020-10-08 18:24 ` Vincenzo Frascino
2020-10-09 8:11 ` Catalin Marinas
2020-10-09 9:56 ` Vincenzo Frascino
2020-10-09 10:16 ` Catalin Marinas
2020-10-09 10:21 ` Vincenzo Frascino
2020-10-01 23:10 ` [PATCH v4 30/39] arm64: kasan: Enable TBI EL1 Andrey Konovalov
2020-10-02 14:10 ` Catalin Marinas
2020-10-01 23:10 ` [PATCH v4 31/39] arm64: kasan: Align allocations for HW_TAGS Andrey Konovalov
2020-10-01 23:10 ` [PATCH v4 32/39] kasan: define KASAN_GRANULE_SIZE " Andrey Konovalov
2020-10-01 23:10 ` [PATCH v4 33/39] kasan, x86, s390: update undef CONFIG_KASAN Andrey Konovalov
2020-10-01 23:10 ` [PATCH v4 34/39] kasan, arm64: expand CONFIG_KASAN checks Andrey Konovalov
2020-10-01 23:10 ` [PATCH v4 35/39] kasan, arm64: implement HW_TAGS runtime Andrey Konovalov
2020-10-01 23:10 ` [PATCH v4 36/39] kasan, arm64: print report from tag fault handler Andrey Konovalov
2020-10-01 23:10 ` [PATCH v4 37/39] kasan, mm: reset tags when accessing metadata Andrey Konovalov
2020-10-01 23:10 ` [PATCH v4 38/39] kasan, arm64: enable CONFIG_KASAN_HW_TAGS Andrey Konovalov
2020-10-01 23:10 ` [PATCH v4 39/39] kasan: add documentation for hardware tag-based mode Andrey Konovalov
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