[v4,19/22] kasan: check object_size in kasan_complete_mode_report_info

Message ID 68c6948175aadd7e7e7deea61725103d64a4528f.1700502145.git.andreyknvl@google.com
State New
Headers
Series stackdepot: allow evicting stack traces |

Commit Message

andrey.konovalov@linux.dev Nov. 20, 2023, 5:47 p.m. UTC
  From: Andrey Konovalov <andreyknvl@google.com>

Check the object size when looking up entries in the stack ring.

If the size of the object for which a report is being printed does not
match the size of the object for which a stack trace has been saved in
the stack ring, the saved stack trace is irrelevant.

Reviewed-by: Alexander Potapenko <glider@google.com>
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>

---

Changes v2->v3:
- Added missing "../slab.h" include for accessing a kmem_cache field.

Changes v1->v2:
- This is a new patch.
---
 mm/kasan/report_tags.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)
  

Patch

diff --git a/mm/kasan/report_tags.c b/mm/kasan/report_tags.c
index 78abdcde5da9..55154743f915 100644
--- a/mm/kasan/report_tags.c
+++ b/mm/kasan/report_tags.c
@@ -7,6 +7,7 @@ 
 #include <linux/atomic.h>
 
 #include "kasan.h"
+#include "../slab.h"
 
 extern struct kasan_stack_ring stack_ring;
 
@@ -58,7 +59,8 @@  void kasan_complete_mode_report_info(struct kasan_report_info *info)
 		entry = &stack_ring.entries[i % stack_ring.size];
 
 		if (kasan_reset_tag(entry->ptr) != info->object ||
-		    get_tag(entry->ptr) != get_tag(info->access_addr))
+		    get_tag(entry->ptr) != get_tag(info->access_addr) ||
+		    info->cache->object_size != entry->size)
 			continue;
 
 		if (entry->is_free) {