fix(mem): fix TLSF returning the wrong pointer when the requested size is too large (#3325)

* test(mem) add test for #3324

* fix(tlsf) don't return the same pointer if the requested size is too large

src/misc/lv_tlsf.c

@@ -1208,6 +1208,10 @@ void * lv_tlsf_realloc(lv_tlsf_t tlsf, void * ptr, size_t size)
         const size_t cursize = block_size(block);
         const size_t combined = cursize + block_size(next) + block_header_overhead;
         const size_t adjust = adjust_request_size(size, ALIGN_SIZE);
+        if(size > cursize && adjust == 0) {
+            /* The request is probably too large, fail */
+            return NULL;
+        }
 
         tlsf_assert(!block_is_free(block) && "block already marked as free");
 

tests/src/test_cases/test_mem.c

@@ -0,0 +1,26 @@
+#if LV_BUILD_TEST
+#include "../lvgl.h"
+
+#include "unity/unity.h"
+
+void setUp(void)
+{
+    /* Function run before every test */
+}
+
+void tearDown(void)
+{
+    /* Function run after every test */
+}
+
+/* #3324 */
+void test_mem_buf_realloc(void)
+{
+#if LV_MEM_CUSTOM == 0
+    void * buf1 = lv_mem_alloc(20);
+    void * buf2 = lv_mem_realloc(buf1, LV_MEM_SIZE + 16384);
+    TEST_ASSERT_NULL(buf2);
+#endif
+}
+
+#endif