From b8ad202da1336550e6987a9c673d1a23e4b26e7b Mon Sep 17 00:00:00 2001
From: Aleksey Midenkov <midenok@gmail.com>
Date: Tue, 3 Dec 2024 13:49:43 +0300
Subject: [PATCH] MDEV-34770 UBSAN: runtime error: load of address 0x... with 
    insufficient space for an object of type 'uchar' in sys_vars.inl

Disable UBSAN for global_var_ptr()/session_var_ptr() (none of
"undefined" suboptions for gcc-13 worked).
---
 sql/set_var.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/sql/set_var.h b/sql/set_var.h
index c8da3c1c169..416993e5c34 100644
--- a/sql/set_var.h
+++ b/sql/set_var.h
@@ -247,9 +247,11 @@ protected:
     Typically it's the same as session_value_ptr(), but it's different,
     for example, for ENUM, that is printed as a string, but stored as a number.
   */
+  __attribute__((no_sanitize("undefined")))
   uchar *session_var_ptr(THD *thd) const
   { return ((uchar*)&(thd->variables)) + offset; }
 
+  __attribute__((no_sanitize("undefined")))
   uchar *global_var_ptr() const
   { return ((uchar*)&global_system_variables) + offset; }