1 files changed, 6 insertions, 1 deletions

diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c
index b5a7f928234b..75bdf2ab3d7c 100644
--- a/arch/x86/xen/setup.c
+++ b/arch/x86/xen/setup.c
@@ -179,8 +179,13 @@ char * __init xen_memory_setup(void)
         e820.nr_map = 0;
         xen_extra_mem_start = mem_end;
         for (i = 0; i < memmap.nr_entries; i++) {
-                unsigned long long end = map[i].addr + map[i].size;
+                unsigned long long end;
 
+                /* Guard against non-page aligned E820 entries. */
+                if (map[i].type == E820_RAM)
+                        map[i].size -= (map[i].size + map[i].addr) % PAGE_SIZE;
+
+                end = map[i].addr + map[i].size;
                 if (map[i].type == E820_RAM && end > mem_end) {
                         /* RAM off the end - may be partially included */
                         u64 delta = min(map[i].size, end - mem_end);