summaryrefslogtreecommitdiffstats
path: root/mm
diff options
context:
space:
mode:
authorKuan-Ying Lee <Kuan-Ying.Lee@mediatek.com>2022-06-15 08:22:18 +0200
committerakpm <akpm@linux-foundation.org>2022-07-18 02:14:33 +0200
commit3de0de758029a0beb1d47facd3d390d2804a3e94 (patch)
tree088f7bc44ea4a7dfe21060ee870332f58d5565f9 /mm
parentdoc: proc: fix the description to THPeligible (diff)
downloadlinux-3de0de758029a0beb1d47facd3d390d2804a3e94.tar.xz
linux-3de0de758029a0beb1d47facd3d390d2804a3e94.zip
kasan: separate double free case from invalid free
Currently, KASAN describes all invalid-free/double-free bugs as "double-free or invalid-free". This is ambiguous. KASAN should report "double-free" when a double-free is a more likely cause (the address points to the start of an object) and report "invalid-free" otherwise [1]. [1] https://bugzilla.kernel.org/show_bug.cgi?id=212193 Link: https://lkml.kernel.org/r/20220615062219.22618-1-Kuan-Ying.Lee@mediatek.com Signed-off-by: Kuan-Ying Lee <Kuan-Ying.Lee@mediatek.com> Reviewed-by: Dmitry Vyukov <dvyukov@google.com> Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Alexander Potapenko <glider@google.com> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Cc: Matthias Brugger <matthias.bgg@gmail.com> Cc: Chinwen Chang <chinwen.chang@mediatek.com> Cc: Yee Lee <yee.lee@mediatek.com> Cc: Andrew Yang <andrew.yang@mediatek.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm')
-rw-r--r--mm/kasan/common.c8
-rw-r--r--mm/kasan/kasan.h3
-rw-r--r--mm/kasan/report.c12
3 files changed, 14 insertions, 9 deletions
diff --git a/mm/kasan/common.c b/mm/kasan/common.c
index c40c0e7b3b5f..707c3a527fcb 100644
--- a/mm/kasan/common.c
+++ b/mm/kasan/common.c
@@ -343,7 +343,7 @@ static inline bool ____kasan_slab_free(struct kmem_cache *cache, void *object,
if (unlikely(nearest_obj(cache, virt_to_slab(object), object) !=
object)) {
- kasan_report_invalid_free(tagged_object, ip);
+ kasan_report_invalid_free(tagged_object, ip, KASAN_REPORT_INVALID_FREE);
return true;
}
@@ -352,7 +352,7 @@ static inline bool ____kasan_slab_free(struct kmem_cache *cache, void *object,
return false;
if (!kasan_byte_accessible(tagged_object)) {
- kasan_report_invalid_free(tagged_object, ip);
+ kasan_report_invalid_free(tagged_object, ip, KASAN_REPORT_DOUBLE_FREE);
return true;
}
@@ -377,12 +377,12 @@ bool __kasan_slab_free(struct kmem_cache *cache, void *object,
static inline bool ____kasan_kfree_large(void *ptr, unsigned long ip)
{
if (ptr != page_address(virt_to_head_page(ptr))) {
- kasan_report_invalid_free(ptr, ip);
+ kasan_report_invalid_free(ptr, ip, KASAN_REPORT_INVALID_FREE);
return true;
}
if (!kasan_byte_accessible(ptr)) {
- kasan_report_invalid_free(ptr, ip);
+ kasan_report_invalid_free(ptr, ip, KASAN_REPORT_DOUBLE_FREE);
return true;
}
diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h
index 610d60d6e5b8..01c03e45acd4 100644
--- a/mm/kasan/kasan.h
+++ b/mm/kasan/kasan.h
@@ -125,6 +125,7 @@ static inline bool kasan_sync_fault_possible(void)
enum kasan_report_type {
KASAN_REPORT_ACCESS,
KASAN_REPORT_INVALID_FREE,
+ KASAN_REPORT_DOUBLE_FREE,
};
struct kasan_report_info {
@@ -277,7 +278,7 @@ static inline void kasan_print_address_stack_frame(const void *addr) { }
bool kasan_report(unsigned long addr, size_t size,
bool is_write, unsigned long ip);
-void kasan_report_invalid_free(void *object, unsigned long ip);
+void kasan_report_invalid_free(void *object, unsigned long ip, enum kasan_report_type type);
struct page *kasan_addr_to_page(const void *addr);
struct slab *kasan_addr_to_slab(const void *addr);
diff --git a/mm/kasan/report.c b/mm/kasan/report.c
index b341a191651d..fe3f606b3a98 100644
--- a/mm/kasan/report.c
+++ b/mm/kasan/report.c
@@ -176,8 +176,12 @@ static void end_report(unsigned long *flags, void *addr)
static void print_error_description(struct kasan_report_info *info)
{
if (info->type == KASAN_REPORT_INVALID_FREE) {
- pr_err("BUG: KASAN: double-free or invalid-free in %pS\n",
- (void *)info->ip);
+ pr_err("BUG: KASAN: invalid-free in %pS\n", (void *)info->ip);
+ return;
+ }
+
+ if (info->type == KASAN_REPORT_DOUBLE_FREE) {
+ pr_err("BUG: KASAN: double-free in %pS\n", (void *)info->ip);
return;
}
@@ -433,7 +437,7 @@ static void print_report(struct kasan_report_info *info)
}
}
-void kasan_report_invalid_free(void *ptr, unsigned long ip)
+void kasan_report_invalid_free(void *ptr, unsigned long ip, enum kasan_report_type type)
{
unsigned long flags;
struct kasan_report_info info;
@@ -448,7 +452,7 @@ void kasan_report_invalid_free(void *ptr, unsigned long ip)
start_report(&flags, true);
- info.type = KASAN_REPORT_INVALID_FREE;
+ info.type = type;
info.access_addr = ptr;
info.first_bad_addr = kasan_reset_tag(ptr);
info.access_size = 0;