From: Andrey Konovalov <andreyknvl@google.com>
To: Andrey Ryabinin <aryabinin@virtuozzo.com>,
Alexander Potapenko <glider@google.com>,
Dmitry Vyukov <dvyukov@google.com>,
Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will.deacon@arm.com>,
Christoph Lameter <cl@linux.com>,
Andrew Morton <akpm@linux-foundation.org>,
Mark Rutland <mark.rutland@arm.com>,
Nick Desaulniers <ndesaulniers@google.com>,
Marc Zyngier <marc.zyngier@arm.com>,
Dave Martin <dave.martin@arm.com>,
Ard Biesheuvel <ard.biesheuvel@linaro.org>,
"Eric W . Biederman" <ebiederm@xmission.com>,
Ingo Molnar <mingo@kernel.org>,
Paul Lawrence <paullawrence@google.com>,
Geert Uytterhoeven <geert@linux-m68k.org>,
Arnd Bergmann <arnd@arndb.de>,
"Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Kate Stewart <kstewart@linuxfoundation.org>,
Mike Rapoport <rppt@linux.vnet.ibm.com>,
kasan-dev@googlegroups.com, linux-doc@vger.kernel.org,
linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
linux-sparse@vger.kernel.org, linux-mm@kvack.org,
linux-kbuild@vger.kernel.org
Cc: Kostya Serebryany <kcc@google.com>,
Evgeniy Stepanov <eugenis@google.com>,
Lee Smith <Lee.Smith@arm.com>,
Ramana Radhakrishnan <Ramana.Radhakrishnan@arm.com>,
Jacob Bramley <Jacob.Bramley@arm.com>,
Ruben Ayrapetyan <Ruben.Ayrapetyan@arm.com>,
Jann Horn <jannh@google.com>, Mark Brand <markbrand@google.com>,
Chintan Pandya <cpandya@codeaurora.org>,
Vishwath Mohan <vishwath@google.com>,
Andrey Konovalov <andreyknvl@google.com>
Subject: [PATCH v13 17/25] kasan: add bug reporting routines for tag-based mode
Date: Thu, 6 Dec 2018 13:24:35 +0100 [thread overview]
Message-ID: <aee6897b1bd077732a315fd84c6b4f234dbfdfcb.1544099024.git.andreyknvl@google.com> (raw)
In-Reply-To: <cover.1544099024.git.andreyknvl@google.com>
This commit adds rountines, that print tag-based KASAN error reports.
Those are quite similar to generic KASAN, the difference is:
1. The way tag-based KASAN finds the first bad shadow cell (with a
mismatching tag). Tag-based KASAN compares memory tags from the shadow
memory to the pointer tag.
2. Tag-based KASAN reports all bugs with the "KASAN: invalid-access"
header.
Also simplify generic KASAN find_first_bad_addr.
Reviewed-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
---
mm/kasan/generic_report.c | 16 ++++-------
mm/kasan/kasan.h | 5 ++++
mm/kasan/report.c | 57 +++++++++++++++++++++------------------
mm/kasan/tags_report.c | 18 +++++++++++++
4 files changed, 59 insertions(+), 37 deletions(-)
diff --git a/mm/kasan/generic_report.c b/mm/kasan/generic_report.c
index 5201d1770700..a4604cceae59 100644
--- a/mm/kasan/generic_report.c
+++ b/mm/kasan/generic_report.c
@@ -33,16 +33,13 @@
#include "kasan.h"
#include "../slab.h"
-static const void *find_first_bad_addr(const void *addr, size_t size)
+void *find_first_bad_addr(void *addr, size_t size)
{
- u8 shadow_val = *(u8 *)kasan_mem_to_shadow(addr);
- const void *first_bad_addr = addr;
+ void *p = addr;
- while (!shadow_val && first_bad_addr < addr + size) {
- first_bad_addr += KASAN_SHADOW_SCALE_SIZE;
- shadow_val = *(u8 *)kasan_mem_to_shadow(first_bad_addr);
- }
- return first_bad_addr;
+ while (p < addr + size && !(*(u8 *)kasan_mem_to_shadow(p)))
+ p += KASAN_SHADOW_SCALE_SIZE;
+ return p;
}
static const char *get_shadow_bug_type(struct kasan_access_info *info)
@@ -50,9 +47,6 @@ static const char *get_shadow_bug_type(struct kasan_access_info *info)
const char *bug_type = "unknown-crash";
u8 *shadow_addr;
- info->first_bad_addr = find_first_bad_addr(info->access_addr,
- info->access_size);
-
shadow_addr = (u8 *)kasan_mem_to_shadow(info->first_bad_addr);
/*
diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h
index 33cc3b0e017e..82a23b23ff93 100644
--- a/mm/kasan/kasan.h
+++ b/mm/kasan/kasan.h
@@ -119,6 +119,7 @@ void kasan_poison_shadow(const void *address, size_t size, u8 value);
void check_memory_region(unsigned long addr, size_t size, bool write,
unsigned long ret_ip);
+void *find_first_bad_addr(void *addr, size_t size);
const char *get_bug_type(struct kasan_access_info *info);
void kasan_report(unsigned long addr, size_t size,
@@ -139,10 +140,14 @@ static inline void quarantine_remove_cache(struct kmem_cache *cache) { }
#ifdef CONFIG_KASAN_SW_TAGS
+void print_tags(u8 addr_tag, const void *addr);
+
u8 random_tag(void);
#else
+static inline void print_tags(u8 addr_tag, const void *addr) { }
+
static inline u8 random_tag(void)
{
return 0;
diff --git a/mm/kasan/report.c b/mm/kasan/report.c
index 64a74f334c45..214d85035f99 100644
--- a/mm/kasan/report.c
+++ b/mm/kasan/report.c
@@ -64,11 +64,10 @@ static int __init kasan_set_multi_shot(char *str)
}
__setup("kasan_multi_shot", kasan_set_multi_shot);
-static void print_error_description(struct kasan_access_info *info,
- const char *bug_type)
+static void print_error_description(struct kasan_access_info *info)
{
pr_err("BUG: KASAN: %s in %pS\n",
- bug_type, (void *)info->ip);
+ get_bug_type(info), (void *)info->ip);
pr_err("%s of size %zu at addr %px by task %s/%d\n",
info->is_write ? "Write" : "Read", info->access_size,
info->access_addr, current->comm, task_pid_nr(current));
@@ -272,6 +271,8 @@ void kasan_report_invalid_free(void *object, unsigned long ip)
start_report(&flags);
pr_err("BUG: KASAN: double-free or invalid-free in %pS\n", (void *)ip);
+ print_tags(get_tag(object), reset_tag(object));
+ object = reset_tag(object);
pr_err("\n");
print_address_description(object);
pr_err("\n");
@@ -279,41 +280,45 @@ void kasan_report_invalid_free(void *object, unsigned long ip)
end_report(&flags);
}
-static void kasan_report_error(struct kasan_access_info *info)
-{
- unsigned long flags;
-
- start_report(&flags);
-
- print_error_description(info, get_bug_type(info));
- pr_err("\n");
-
- if (!addr_has_shadow(info->access_addr)) {
- dump_stack();
- } else {
- print_address_description((void *)info->access_addr);
- pr_err("\n");
- print_shadow_for_address(info->first_bad_addr);
- }
-
- end_report(&flags);
-}
-
void kasan_report(unsigned long addr, size_t size,
bool is_write, unsigned long ip)
{
struct kasan_access_info info;
+ void *tagged_addr;
+ void *untagged_addr;
+ unsigned long flags;
if (likely(!report_enabled()))
return;
disable_trace_on_warning();
- info.access_addr = (void *)addr;
- info.first_bad_addr = (void *)addr;
+ tagged_addr = (void *)addr;
+ untagged_addr = reset_tag(tagged_addr);
+
+ info.access_addr = tagged_addr;
+ if (addr_has_shadow(untagged_addr))
+ info.first_bad_addr = find_first_bad_addr(tagged_addr, size);
+ else
+ info.first_bad_addr = untagged_addr;
info.access_size = size;
info.is_write = is_write;
info.ip = ip;
- kasan_report_error(&info);
+ start_report(&flags);
+
+ print_error_description(&info);
+ if (addr_has_shadow(untagged_addr))
+ print_tags(get_tag(tagged_addr), info.first_bad_addr);
+ pr_err("\n");
+
+ if (addr_has_shadow(untagged_addr)) {
+ print_address_description(untagged_addr);
+ pr_err("\n");
+ print_shadow_for_address(info.first_bad_addr);
+ } else {
+ dump_stack();
+ }
+
+ end_report(&flags);
}
diff --git a/mm/kasan/tags_report.c b/mm/kasan/tags_report.c
index 8af15e87d3bc..573c51d20d09 100644
--- a/mm/kasan/tags_report.c
+++ b/mm/kasan/tags_report.c
@@ -37,3 +37,21 @@ const char *get_bug_type(struct kasan_access_info *info)
{
return "invalid-access";
}
+
+void *find_first_bad_addr(void *addr, size_t size)
+{
+ u8 tag = get_tag(addr);
+ void *p = reset_tag(addr);
+ void *end = p + size;
+
+ while (p < end && tag == *(u8 *)kasan_mem_to_shadow(p))
+ p += KASAN_SHADOW_SCALE_SIZE;
+ return p;
+}
+
+void print_tags(u8 addr_tag, const void *addr)
+{
+ u8 *shadow = (u8 *)kasan_mem_to_shadow(addr);
+
+ pr_err("Pointer tag: [%02x], memory tag: [%02x]\n", addr_tag, *shadow);
+}
--
2.20.0.rc1.387.gf8505762e3-goog
next prev parent reply other threads:[~2018-12-06 12:25 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-12-06 12:24 [PATCH v13 00/25] kasan: add software tag-based mode for arm64 Andrey Konovalov
2018-12-06 12:24 ` [PATCH v13 01/25] kasan, mm: change hooks signatures Andrey Konovalov
2018-12-06 12:24 ` [PATCH v13 02/25] kasan, slub: handle pointer tags in early_kmem_cache_node_alloc Andrey Konovalov
2018-12-06 12:24 ` [PATCH v13 03/25] kasan: move common generic and tag-based code to common.c Andrey Konovalov
2018-12-06 12:24 ` [PATCH v13 04/25] kasan: rename source files to reflect the new naming scheme Andrey Konovalov
2018-12-06 12:24 ` [PATCH v13 05/25] kasan: add CONFIG_KASAN_GENERIC and CONFIG_KASAN_SW_TAGS Andrey Konovalov
2018-12-11 15:28 ` Luc Van Oostenryck
2018-12-11 16:02 ` Andrey Konovalov
2018-12-06 12:24 ` [PATCH v13 06/25] kasan, arm64: adjust shadow size for tag-based mode Andrey Konovalov
2018-12-06 12:24 ` [PATCH v13 07/25] kasan: rename kasan_zero_page to kasan_early_shadow_page Andrey Konovalov
2018-12-06 12:24 ` [PATCH v13 08/25] kasan: initialize shadow to 0xff for tag-based mode Andrey Konovalov
[not found] ` <CAP=VYLo-o8vpGrpM_+0jdvxLC9uxw+F7_OtsSfRyq24HR1dDwA@mail.gmail.com>
2018-12-10 12:12 ` Andrey Konovalov
2018-12-06 12:24 ` [PATCH v13 09/25] arm64: move untagged_addr macro from uaccess.h to memory.h Andrey Konovalov
2018-12-06 12:24 ` [PATCH v13 10/25] kasan: add tag related helper functions Andrey Konovalov
2018-12-06 12:24 ` [PATCH v13 11/25] kasan, arm64: untag address in _virt_addr_is_linear Andrey Konovalov
2018-12-06 12:24 ` [PATCH v13 12/25] kasan: preassign tags to objects with ctors or SLAB_TYPESAFE_BY_RCU Andrey Konovalov
2018-12-06 12:24 ` [PATCH v13 13/25] kasan, arm64: fix up fault handling logic Andrey Konovalov
2018-12-06 12:24 ` [PATCH v13 14/25] kasan, arm64: enable top byte ignore for the kernel Andrey Konovalov
2018-12-06 12:24 ` [PATCH v13 15/25] kasan, mm: perform untagged pointers comparison in krealloc Andrey Konovalov
2018-12-06 12:24 ` [PATCH v13 16/25] kasan: split out generic_report.c from report.c Andrey Konovalov
2018-12-06 12:24 ` Andrey Konovalov [this message]
2018-12-06 12:24 ` [PATCH v13 18/25] mm: move obj_to_index to include/linux/slab_def.h Andrey Konovalov
2018-12-06 12:24 ` [PATCH v13 19/25] kasan: add hooks implementation for tag-based mode Andrey Konovalov
2018-12-11 16:22 ` Vincenzo Frascino
2018-12-12 15:04 ` Andrey Konovalov
2018-12-14 12:35 ` Vincenzo Frascino
2018-12-17 19:33 ` Andrey Konovalov
2018-12-17 20:38 ` Andrew Morton
2018-12-18 13:31 ` Andrey Konovalov
2018-12-06 12:24 ` [PATCH v13 20/25] kasan, arm64: add brk handler for inline instrumentation Andrey Konovalov
2018-12-06 12:24 ` [PATCH v13 21/25] kasan, mm, arm64: tag non slab memory allocated via pagealloc Andrey Konovalov
2018-12-06 12:24 ` [PATCH v13 22/25] kasan: add __must_check annotations to kasan hooks Andrey Konovalov
2018-12-06 12:24 ` [PATCH v13 23/25] kasan, arm64: select HAVE_ARCH_KASAN_SW_TAGS Andrey Konovalov
2018-12-06 12:24 ` [PATCH v13 24/25] kasan: update documentation Andrey Konovalov
2018-12-06 12:24 ` [PATCH v13 25/25] kasan: add SPDX-License-Identifier mark to source files Andrey Konovalov
2018-12-11 15:18 ` [PATCH v13 00/25] kasan: add software tag-based mode for arm64 Will Deacon
2018-12-11 15:57 ` Andrey Konovalov
2018-12-11 16:00 ` Will Deacon
2018-12-11 21:44 ` Andrew Morton
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