kasan: better invalid/double-free report header

Update the report header for invalid- and double-free bugs to contain the
address being freed:

BUG: KASAN: invalid-free in kfree+0x280/0x2a8
Free of addr ffff00000beac001 by task kunit_try_catch/99

Link: https://lkml.kernel.org/r/fce40f8dbd160972fe01a1ff39d0c426c310e4b7.1662852281.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/mm/kasan/report.c b/mm/kasan/report.c
index 39e8e5a80b82942a70d3aa2deb2d2c43520110b4..df3602062bfd61040d5def7d6dcc345ac3396ce5 100644 (file)
--- a/mm/kasan/report.c
+++ b/mm/kasan/report.c
@@ -175,17 +175,14 @@ 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: invalid-free in %pS\n", (void *)info->ip);
-               return;
-       }
+       pr_err("BUG: KASAN: %s in %pS\n", info->bug_type, (void *)info->ip);
 
-       if (info->type == KASAN_REPORT_DOUBLE_FREE) {
-               pr_err("BUG: KASAN: double-free in %pS\n", (void *)info->ip);
+       if (info->type != KASAN_REPORT_ACCESS) {
+               pr_err("Free of addr %px by task %s/%d\n",
+                       info->access_addr, current->comm, task_pid_nr(current));
                return;
        }
 
-       pr_err("BUG: KASAN: %s in %pS\n", info->bug_type, (void *)info->ip);
        if (info->access_size)
                pr_err("%s of size %zu at addr %px by task %s/%d\n",
                        info->is_write ? "Write" : "Read", info->access_size,
@@ -420,6 +417,18 @@ static void complete_report_info(struct kasan_report_info *info)
        } else
                info->cache = info->object = NULL;
 
+       switch (info->type) {
+       case KASAN_REPORT_INVALID_FREE:
+               info->bug_type = "invalid-free";
+               break;
+       case KASAN_REPORT_DOUBLE_FREE:
+               info->bug_type = "double-free";
+               break;
+       default:
+               /* bug_type filled in by kasan_complete_mode_report_info. */
+               break;
+       }
+
        /* Fill in mode-specific report info fields. */
        kasan_complete_mode_report_info(info);
 }

diff --git a/mm/kasan/report_generic.c b/mm/kasan/report_generic.c
index 087c1d8c8145668c2a5f4c918455b8b8ea02246c..043c94b04605402860a0553ef63b4bcd495f9917 100644 (file)
--- a/mm/kasan/report_generic.c
+++ b/mm/kasan/report_generic.c
@@ -132,7 +132,8 @@ void kasan_complete_mode_report_info(struct kasan_report_info *info)
        struct kasan_alloc_meta *alloc_meta;
        struct kasan_free_meta *free_meta;
 
-       info->bug_type = get_bug_type(info);
+       if (!info->bug_type)
+               info->bug_type = get_bug_type(info);
 
        if (!info->cache || !info->object)
                return;

diff --git a/mm/kasan/report_tags.c b/mm/kasan/report_tags.c
index d3510424d29becbaa92207f0abcc29d3549f8cb2..ecede06ef374aafc7cf0d5f275667ee0499a956a 100644 (file)
--- a/mm/kasan/report_tags.c
+++ b/mm/kasan/report_tags.c
@@ -37,7 +37,7 @@ void kasan_complete_mode_report_info(struct kasan_report_info *info)
        bool is_free;
        bool alloc_found = false, free_found = false;
 
-       if (!info->cache || !info->object) {
+       if ((!info->cache || !info->object) && !info->bug_type) {
                info->bug_type = get_common_bug_type(info);
                return;
        }