mm: prevent get_user_pages() from overflowing page refcount

[linux-2.6-microblaze.git] / mm / mmap.c

diff --git a/mm/mmap.c b/mm/mmap.c
index f901065..fc1809b 100644 (file)
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -2426,12 +2426,11 @@ int expand_downwards(struct vm_area_struct *vma,
 {
        struct mm_struct *mm = vma->vm_mm;
        struct vm_area_struct *prev;
-       int error;
+       int error = 0;
 
        address &= PAGE_MASK;
-       error = security_mmap_addr(address);
-       if (error)
-               return error;
+       if (address < mmap_min_addr)
+               return -EPERM;
 
        /* Enforce stack_guard_gap */
        prev = vma->vm_prev;