If we want to trap NULL vma's, we'd better be sure
that we don't dereference it first..
Dave
--- linux-2.6.5/mm/mprotect.c~ 2004-04-16 21:52:47.000000000 +0100
+++ linux-2.6.5/mm/mprotect.c 2004-04-16 21:53:12.000000000 +0100
@@ -114,10 +114,11 @@
mprotect_attempt_merge(struct vm_area_struct *vma, struct vm_area_struct *prev,
unsigned long end, int newflags)
{
- struct mm_struct * mm = vma->vm_mm;
+ struct mm_struct * mm;
if (!prev || !vma)
return 0;
+ mm = vma->vm_mm;
if (prev->vm_end != vma->vm_start)
return 0;
if (!can_vma_merge(prev, newflags))