diff --git a/arch/x86/kernel/kexec-bzimage64.c b/arch/x86/kernel/kexec-bzimage64.c
index ca05f86481aa..ca83f7ac388b 100644
--- a/arch/x86/kernel/kexec-bzimage64.c
+++ b/arch/x86/kernel/kexec-bzimage64.c
@@ -72,15 +72,16 @@ static int setup_cmdline(struct kimage *image, struct boot_params *params,
 			 unsigned long cmdline_len)
 {
 	char *cmdline_ptr = ((char *)params) + cmdline_offset;
-	unsigned long cmdline_ptr_phys, len;
+	unsigned long cmdline_ptr_phys, len = 0;
 	uint32_t cmdline_low_32, cmdline_ext_32;
 
-	memcpy(cmdline_ptr, cmdline, cmdline_len);
 	if (image->type == KEXEC_TYPE_CRASH) {
-		len = sprintf(cmdline_ptr + cmdline_len - 1,
-			" elfcorehdr=0x%lx", image->arch.elf_load_addr);
-		cmdline_len += len;
+		len = sprintf(cmdline_ptr,
+			"elfcorehdr=0x%lx ", image->arch.elf_load_addr);
 	}
+	memcpy(cmdline_ptr + len, cmdline, cmdline_len);
+	cmdline_len += len;
+
 	cmdline_ptr[cmdline_len - 1] = '\0';
 
 	pr_debug("Final command line is: %s\n", cmdline_ptr);