kasan: improve double-free report format
Changes double-free report header from
BUG: Double free or freeing an invalid pointer
Unexpected shadow byte: 0xFB
to
BUG: KASAN: double-free or invalid-free in kmalloc_oob_left+0xe5/0xef
This makes a bug uniquely identifiable by the first report line. To
account for removing of the unexpected shadow value, print shadow bytes
at the end of the report as in reports for other kinds of bugs.
Change-Id: Ie708e7fd5cc4947ee7bc7daf6dcff13248097d0b
Link: http://lkml.kernel.org/r/20170302134851.101218-9-andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Acked-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Git-commit: 5ab6d91ac998158d04f9563335aa5f1409eda971
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Signed-off-by: Trilok Soni <tsoni@codeaurora.org>
diff --git a/mm/kasan/report.c b/mm/kasan/report.c
index 44166a6..ca3e926 100644
--- a/mm/kasan/report.c
+++ b/mm/kasan/report.c
@@ -238,22 +238,8 @@
describe_object_addr(cache, object, addr);
}
-void kasan_report_double_free(struct kmem_cache *cache, void *object,
- s8 shadow)
+static void print_address_description(void *addr)
{
- unsigned long flags;
-
- kasan_start_report(&flags);
- pr_err("BUG: Double free or freeing an invalid pointer\n");
- pr_err("Unexpected shadow byte: 0x%hhX\n", shadow);
- dump_stack();
- describe_object(cache, object, NULL);
- kasan_end_report(&flags);
-}
-
-static void print_address_description(struct kasan_access_info *info)
-{
- void *addr = (void *)info->access_addr;
struct page *page = addr_to_page(addr);
dump_stack();
@@ -328,6 +314,18 @@
}
}
+void kasan_report_double_free(struct kmem_cache *cache, void *object,
+ void *ip)
+{
+ unsigned long flags;
+
+ kasan_start_report(&flags);
+ pr_err("BUG: KASAN: double-free or invalid-free in %pS\n", ip);
+ print_address_description(object);
+ print_shadow_for_address(object);
+ kasan_end_report(&flags);
+}
+
static void kasan_report_error(struct kasan_access_info *info)
{
unsigned long flags;
@@ -339,7 +337,7 @@
if (!addr_has_shadow(info)) {
dump_stack();
} else {
- print_address_description(info);
+ print_address_description((void *)info->access_addr);
print_shadow_for_address(info->first_bad_addr);
}