diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c
index 5bd2de11829ad7c325b90ad81cdd54fa54a2f4c6..0761bfa4157966373b91edbc2cc356936a980107 100644
--- a/arch/x86/kernel/alternative.c
+++ b/arch/x86/kernel/alternative.c
@@ -370,6 +370,17 @@ void __init_or_module noinline apply_alternatives(struct alt_instr *start,
 	u8 insnbuf[MAX_PATCH_LEN];
 
 	DPRINTK("alt table %px, -> %px", start, end);
+
+	/*
+	 * In the case CONFIG_X86_5LEVEL=y, KASAN_SHADOW_START is defined using
+	 * cpu_feature_enabled(X86_FEATURE_LA57) and is therefore patched here.
+	 * During the process, KASAN becomes confused seeing partial LA57
+	 * conversion and triggers a false-positive out-of-bound report.
+	 *
+	 * Disable KASAN until the patching is complete.
+	 */
+	kasan_disable_current();
+
 	/*
 	 * The scan order should be from start to end. A later scanned
 	 * alternative code can overwrite previously scanned alternative code.
@@ -430,6 +441,8 @@ void __init_or_module noinline apply_alternatives(struct alt_instr *start,
 
 		text_poke_early(instr, insnbuf, insnbuf_sz);
 	}
+
+	kasan_enable_current();
 }
 
 #ifdef CONFIG_SMP