kasan: call print_report from kasan_report_invalid_free

Call print_report() in kasan_report_invalid_free() instead of calling
printing functions directly.  Compared to the existing implementation of
kasan_report_invalid_free(), print_report() makes sure that the buggy
address has metadata before printing it.

The change requires adding a report type field into kasan_access_info and
using it accordingly.

kasan_report_async() is left as is, as using print_report() will only
complicate the code.

Link: https://lkml.kernel.org/r/9ea6f0604c5d2e1fb28d93dc6c44232c1f8017fe.1646237226.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Marco Elver <elver@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h
index 40b863e289ec3540eecf2fe36208377ac0dbb585..8c9a855152c288ff4efacfb78acc0b61a5b60128 100644 (file)
--- a/mm/kasan/kasan.h
+++ b/mm/kasan/kasan.h
@@ -127,7 +127,13 @@ static inline bool kasan_sync_fault_possible(void)
 #define META_MEM_BYTES_PER_ROW (META_BYTES_PER_ROW * KASAN_GRANULE_SIZE)
 #define META_ROWS_AROUND_ADDR 2
 
+enum kasan_report_type {
+       KASAN_REPORT_ACCESS,
+       KASAN_REPORT_INVALID_FREE,
+};
+
 struct kasan_access_info {
+       enum kasan_report_type type;
        void *access_addr;
        void *first_bad_addr;
        size_t access_size;

diff --git a/mm/kasan/report.c b/mm/kasan/report.c
index 56d5ba2355422305d41f2371c8aba2e4755b3fc3..73348f83b81305a0808b82340f7cb31ab81879d7 100644 (file)
--- a/mm/kasan/report.c
+++ b/mm/kasan/report.c
@@ -86,6 +86,12 @@ __setup("kasan_multi_shot", kasan_set_multi_shot);
 
 static void print_error_description(struct kasan_access_info *info)
 {
+       if (info->type == KASAN_REPORT_INVALID_FREE) {
+               pr_err("BUG: KASAN: double-free or invalid-free in %pS\n",
+                      (void *)info->ip);
+               return;
+       }
+
        pr_err("BUG: KASAN: %s in %pS\n",
                kasan_get_bug_type(info), (void *)info->ip);
        if (info->access_size)
@@ -386,22 +392,6 @@ static bool report_enabled(void)
        return !test_and_set_bit(KASAN_BIT_REPORTED, &kasan_flags);
 }
 
-void kasan_report_invalid_free(void *object, unsigned long ip)
-{
-       unsigned long flags;
-       u8 tag = get_tag(object);
-
-       object = kasan_reset_tag(object);
-
-       start_report(&flags, true);
-       pr_err("BUG: KASAN: double-free or invalid-free in %pS\n", (void *)ip);
-       kasan_print_tags(tag, object);
-       pr_err("\n");
-       print_address_description(object, tag);
-       print_memory_metadata(object);
-       end_report(&flags, object);
-}
-
 #ifdef CONFIG_KASAN_HW_TAGS
 void kasan_report_async(void)
 {
@@ -435,6 +425,25 @@ static void print_report(struct kasan_access_info *info)
        }
 }
 
+void kasan_report_invalid_free(void *ptr, unsigned long ip)
+{
+       unsigned long flags;
+       struct kasan_access_info info;
+
+       start_report(&flags, true);
+
+       info.type = KASAN_REPORT_INVALID_FREE;
+       info.access_addr = ptr;
+       info.first_bad_addr = kasan_reset_tag(ptr);
+       info.access_size = 0;
+       info.is_write = false;
+       info.ip = ip;
+
+       print_report(&info);
+
+       end_report(&flags, ptr);
+}
+
 bool kasan_report(unsigned long addr, size_t size, bool is_write,
                        unsigned long ip)
 {
@@ -451,6 +460,7 @@ bool kasan_report(unsigned long addr, size_t size, bool is_write,
 
        start_report(&irq_flags, true);
 
+       info.type = KASAN_REPORT_ACCESS;
        info.access_addr = ptr;
        info.first_bad_addr = kasan_find_first_bad_addr(ptr, size);
        info.access_size = size;