diff --git a/arch/x86/kernel/crash.c b/arch/x86/kernel/crash.c
index 650830e39e3a..b3ac57f0e068 100644
--- a/arch/x86/kernel/crash.c
+++ b/arch/x86/kernel/crash.c
@@ -23,6 +23,7 @@
 #include <linux/export.h>
 #include <linux/slab.h>
 #include <linux/vmalloc.h>
+#include <linux/overflow.h>
 
 #include <asm/processor.h>
 #include <asm/hardirq.h>
@@ -564,7 +565,7 @@ int crash_setup_memmap_entries(struct kimage *image, struct boot_params *params)
 	struct crash_memmap_data cmd;
 	struct crash_mem *cmem;
 
-	cmem = vzalloc(sizeof(struct crash_mem));
+	cmem = vzalloc(struct_size(cmem, ranges, 1));
 	if (!cmem)
 		return -ENOMEM;