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Diffstat (limited to 'mm/fremap.c')
-rw-r--r--mm/fremap.c7
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. */