UBUNTU: link-to-tracker: update tracking bug

[mirror_ubuntu-bionic-kernel.git] / mm / gup.c

diff --git a/mm/gup.c b/mm/gup.c
index e0d82b6706d72d82637bca5eaef1e35e15a1abdf..d2ba0be714411eb56c49ef10cc94b69276b2c789 100644 (file)
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -544,6 +544,9 @@ static int check_vma_flags(struct vm_area_struct *vma, unsigned long gup_flags)
        if (vm_flags & (VM_IO | VM_PFNMAP))
                return -EFAULT;
 
+       if (gup_flags & FOLL_ANON && !vma_is_anonymous(vma))
+               return -EFAULT;
+
        if (write) {
                if (!(vm_flags & VM_WRITE)) {
                        if (!(gup_flags & FOLL_FORCE))
@@ -1816,9 +1819,12 @@ int get_user_pages_fast(unsigned long start, int nr_pages, int write,
        len = (unsigned long) nr_pages << PAGE_SHIFT;
        end = start + len;
 
+       if (nr_pages <= 0)
+               return 0;
+
        if (unlikely(!access_ok(write ? VERIFY_WRITE : VERIFY_READ,
                                        (void __user *)start, len)))
-               return 0;
+               return -EFAULT;
 
        if (gup_fast_permitted(start, nr_pages, write)) {
                local_irq_disable();