1 files changed, 3 insertions, 2 deletions

diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c
index 3f7777b255aa..91abf5b2fb94 100644
--- a/arch/x86/kernel/e820.c
+++ b/arch/x86/kernel/e820.c
@@ -143,7 +143,7 @@ void __init e820_print_map(char *who)
  *
  */
 int __init sanitize_e820_map(struct e820entry *biosmap, int max_nr_map,
-                                char *pnr_map)
+                                int *pnr_map)
 {
         struct change_member {
                 struct e820entry *pbios; /* pointer to original bios entry */
@@ -204,6 +204,7 @@ static struct e820entry new_bios[E820_X_MAX] __initdata;
                 return -1;
 
         old_nr = *pnr_map;
+        BUG_ON(old_nr > max_nr_map);
 
         /* bail out if we find any unreasonable addresses in bios map */
         for (i = 0; i < old_nr; i++)
@@ -401,7 +402,7 @@ u64 __init update_memory_range(u64 start, u64 size, unsigned old_type,
 
 void __init update_e820(void)
 {
-        u8 nr_map;
+        int nr_map;
 
         nr_map = e820.nr_map;
         if (sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &nr_map))