From 1771d233c9ef1af9734d9806ea71d0e0649c9480 Mon Sep 17 00:00:00 2001
From: yinshengkai <yinshengkai@xiaomi.com>
Date: Mon, 22 Apr 2024 19:43:55 +0800
Subject: [PATCH] mm/kasan: fix kasan_is_poisoned check error

When size is less than or equal to KASAN_SHADOW_SCALE, no check will be performed
We need to check whether the memory is accessible based on bit

Signed-off-by: yinshengkai <yinshengkai@xiaomi.com>
---
 mm/kasan/generic.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/mm/kasan/generic.c b/mm/kasan/generic.c
index 6ea06fcc0d..513279fae1 100644
--- a/mm/kasan/generic.c
+++ b/mm/kasan/generic.c
@@ -211,6 +211,11 @@ bool kasan_is_poisoned(FAR const void *addr, size_t size)
       return false;
     }
 
+  if (size <= KASAN_SHADOW_SCALE)
+    {
+      return ((*p >> bit) & 1);
+    }
+
   nbit = KASAN_BITS_PER_WORD - bit % KASAN_BITS_PER_WORD;
   mask = KASAN_FIRST_WORD_MASK(bit);
   size /= KASAN_SHADOW_SCALE;