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author | Kuan-Ying Lee <Kuan-Ying.Lee@mediatek.com> | 2022-06-15 08:22:18 +0200 |
---|---|---|
committer | akpm <akpm@linux-foundation.org> | 2022-07-18 02:14:33 +0200 |
commit | 3de0de758029a0beb1d47facd3d390d2804a3e94 (patch) | |
tree | 088f7bc44ea4a7dfe21060ee870332f58d5565f9 /mm | |
parent | doc: proc: fix the description to THPeligible (diff) | |
download | linux-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.c | 8 | ||||
-rw-r--r-- | mm/kasan/kasan.h | 3 | ||||
-rw-r--r-- | mm/kasan/report.c | 12 |
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; |