Re: [patch] Staging: tidspbridge: make mmap root-only so it is not a security problem

[Pavel Machek <pavel@ucw.cz>]

Hi!

> >>--- a/drivers/staging/tidspbridge/rmgr/drv_interface.c
> >>+++ b/drivers/staging/tidspbridge/rmgr/drv_interface.c
> >>@@ -258,7 +258,17 @@ err:
> >>  /* This function maps kernel space memory to user space memory. */
> >>  static int bridge_mmap(struct file *filp, struct vm_area_struct *vma)
> >>  {
> >>-	u32 status;
> >>+	int status;
> >>+	struct omap_dsp_platform_data *pdata =
> >>+	    omap_dspbridge_dev->dev.platform_data;
> >>+	unsigned long start = vma->vm_pgoff << PAGE_SHIFT;
> >>+		
> >>+	if (start < pdata->phys_mempool_base)
> >>+		return -EINVAL;
> >>+
> >>+	if (vma->vm_end - vma->vm_start + (start - pdata->phys_mempool_base)
> >>+	    > pdata->phys_mempool_size)
> >This test is vulnerable to integer overflows if you pick a very high
> >value for start.  Consider using the vm_iomap_memory() helper function
> >instead of calling remap_pfn_range() directly.  Commit 7314e613d5ff
> >('Fix a few incorrectly checked [io_]remap_pfn_range() calls') has an
> >example of how the conversion works.
> >
> >regards,
> >dan carpenter
> >
> Dan,
> 
> If that one looks fine, I'll send a correctly formatted patch.

Looks good to me. Feel free to add

Signed-off-by: Pavel Machek <pavel@ucw.cz>
Reported-by: Nico Golde <nico@ngolde.de>
Reported-by: Fabian Yamaguchi <fabs@goesec.de>

									Pavel
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