diff options
Diffstat (limited to 'mm/fremap.c')
| -rw-r--r-- | mm/fremap.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/mm/fremap.c b/mm/fremap.c index 46f5dacf90a..ec520c7b28d 100644 --- a/mm/fremap.c +++ b/mm/fremap.c @@ -125,7 +125,6 @@ SYSCALL_DEFINE5(remap_file_pages, unsigned long, start, unsigned long, size, { struct mm_struct *mm = current->mm; struct address_space *mapping; - unsigned long end = start + size; struct vm_area_struct *vma; int err = -EINVAL; int has_write_lock = 0; @@ -142,6 +141,10 @@ SYSCALL_DEFINE5(remap_file_pages, unsigned long, start, unsigned long, size, if (start + size <= start) return err; + /* Does pgoff wrap? */ + if (pgoff + (size >> PAGE_SHIFT) < pgoff) + return err; + /* Can we represent this offset inside this architecture's pte's? */ #if PTE_FILE_MAX_BITS < BITS_PER_LONG if (pgoff + (size >> PAGE_SHIFT) >= (1UL << PTE_FILE_MAX_BITS)) @@ -168,7 +171,7 @@ SYSCALL_DEFINE5(remap_file_pages, unsigned long, start, unsigned long, size, if (!(vma->vm_flags & VM_CAN_NONLINEAR)) goto out; - if (end <= start || start < vma->vm_start || end > vma->vm_end) + if (start < vma->vm_start || start + size > vma->vm_end) goto out; /* Must set VM_NONLINEAR before any pages are populated. */ |