fbdev: improve fb_mmap bounds checks
Improve fb_mmap bounds checks in gbefb, smscufx, udlfb and vfb drivers to
prevent possible uint overflows.
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Cc: Steve Glendinning <steve.glendinning@smsc.com>
Cc: Bernie Thompson <bernie@plugable.com>
diff --git a/drivers/video/vfb.c b/drivers/video/vfb.c
index 8bc1f93..ee5985e 100644
--- a/drivers/video/vfb.c
+++ b/drivers/video/vfb.c
@@ -420,9 +420,12 @@
unsigned long offset = vma->vm_pgoff << PAGE_SHIFT;
unsigned long page, pos;
- if (offset + size > info->fix.smem_len) {
+ if (vma->vm_pgoff > (~0UL >> PAGE_SHIFT))
return -EINVAL;
- }
+ if (size > info->fix.smem_len)
+ return -EINVAL;
+ if (offset > info->fix.smem_len - size)
+ return -EINVAL;
pos = (unsigned long)info->fix.smem_start + offset;