memblock: ensure there is no overflow in memblock_overlaps_region()

There maybe an overflow in memblock_overlaps_region() if it is called with
base and size such that

	base + size > PHYS_ADDR_MAX

Make sure that memblock_overlaps_region() caps the size to prevent such
overflow and remove now duplicated call to memblock_cap_size() from
memblock_is_region_reserved().

Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Tested-by: Tony Lindgren <tony@atomide.com>

diff --git a/mm/memblock.c b/mm/memblock.c
index 2e25d69..67e0e24 100644 (file)
--- a/mm/memblock.c
+++ b/mm/memblock.c
@@ -182,6 +182,8 @@ bool __init_memblock memblock_overlaps_region(struct memblock_type *type,
 {
        unsigned long i;
 
+       memblock_cap_size(base, &size);
+
        for (i = 0; i < type->cnt; i++)
                if (memblock_addrs_overlap(base, size, type->regions[i].base,
                                           type->regions[i].size))
@@ -1794,7 +1796,6 @@ bool __init_memblock memblock_is_region_memory(phys_addr_t base, phys_addr_t siz
  */
 bool __init_memblock memblock_is_region_reserved(phys_addr_t base, phys_addr_t size)
 {
-       memblock_cap_size(base, &size);
        return memblock_overlaps_region(&memblock.reserved, base, size);
 }