Introduce get_shadow_bug_type() function, which determines bug type
based on the shadow value for a particular kernel address.
Introduce get_wild_bug_type() function, which determines bug type
for addresses which don't have a corresponding shadow value.
Signed-off-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx>
---
mm/kasan/report.c | 40 ++++++++++++++++++++++++++++++----------
1 file changed, 30 insertions(+), 10 deletions(-)
diff --git a/mm/kasan/report.c b/mm/kasan/report.c
index f479365530b6..e3af37b7a74c 100644
--- a/mm/kasan/report.c
+++ b/mm/kasan/report.c
@@ -49,7 +49,13 @@ static const void *find_first_bad_addr(const void *addr, size_t size)
return first_bad_addr;
}
-static void print_error_description(struct kasan_access_info *info)
+static bool addr_has_shadow(struct kasan_access_info *info)
+{
+ return (info->access_addr >=
+ kasan_shadow_to_mem((void *)KASAN_SHADOW_START));
+}
+
+static const char *get_shadow_bug_type(struct kasan_access_info *info)
{
const char *bug_type = "unknown-crash";
u8 *shadow_addr;
@@ -96,6 +102,27 @@ static void print_error_description(struct kasan_access_info *info)
break;
}
+ return bug_type;
+}
+
+static const char *get_wild_bug_type(struct kasan_access_info *info)
+{
+ const char *bug_type;
+
+ if ((unsigned long)info->access_addr < PAGE_SIZE)
+ bug_type = "null-ptr-deref";
+ else if ((unsigned long)info->access_addr < TASK_SIZE)
+ bug_type = "user-memory-access";
+ else
+ bug_type = "wild-memory-access";
+
+ return bug_type;
+}
+
+static void print_error_description(struct kasan_access_info *info)
+{
+ const char *bug_type = get_shadow_bug_type(info);
+
pr_err("BUG: KASAN: %s in %pS at addr %p\n",
bug_type, (void *)info->ip,
info->access_addr);
@@ -265,18 +292,11 @@ static void print_shadow_for_address(const void *addr)
static void kasan_report_error(struct kasan_access_info *info)
{
unsigned long flags;
- const char *bug_type;
kasan_start_report(&flags);
- if (info->access_addr <
- kasan_shadow_to_mem((void *)KASAN_SHADOW_START)) {
- if ((unsigned long)info->access_addr < PAGE_SIZE)
- bug_type = "null-ptr-deref";
- else if ((unsigned long)info->access_addr < TASK_SIZE)
- bug_type = "user-memory-access";
- else
- bug_type = "wild-memory-access";
+ if (!addr_has_shadow(info)) {
+ const char *bug_type = get_wild_bug_type(info);
pr_err("BUG: KASAN: %s on address %p\n",
bug_type, info->access_addr);
pr_err("%s of size %zu by task %s/%d\n",
--
2.12.1.578.ge9c3154ca4-goog
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