x86: change size if e820_update/remove_range

in case someone using crazy parameter while calling them.

Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 6 insertions, 0 deletions

diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c
index 15b4393ff9bf..1b76b25b4d9a 100644
--- a/arch/x86/kernel/e820.c
+++ b/arch/x86/kernel/e820.c
@@ -405,6 +405,9 @@ u64 __init e820_update_range(u64 start, u64 size, unsigned old_type,
 
         BUG_ON(old_type == new_type);
 
+        if (size > (ULLONG_MAX - start))
+                size = ULLONG_MAX - start;
+
         for (i = 0; i < e820.nr_map; i++) {
                 struct e820entry *ei = &e820.map[i];
                 u64 final_start, final_end;
@@ -441,6 +444,9 @@ u64 __init e820_remove_range(u64 start, u64 size, unsigned old_type,
         int i;
         u64 real_removed_size = 0;
 
+        if (size > (ULLONG_MAX - start))
+                size = ULLONG_MAX - start;
+
         for (i = 0; i < e820.nr_map; i++) {
                 struct e820entry *ei = &e820.map[i];
                 u64 final_start, final_end;