Re: [PATCH v8 0/7] Add pci_dev_for_each_resource() helper and update users

[Bjorn Helgaas <helgaas@kernel.org>]

On Tue, Apr 04, 2023 at 11:11:01AM -0500, Bjorn Helgaas wrote:
> On Thu, Mar 30, 2023 at 07:24:27PM +0300, Andy Shevchenko wrote:
> > Provide two new helper macros to iterate over PCI device resources and
> > convert users.

> Applied 2-7 to pci/resource for v6.4, thanks, I really like this!

This is 09cc90063240 ("PCI: Introduce pci_dev_for_each_resource()")
upstream now.

Coverity complains about each use, sample below from
drivers/pci/vgaarb.c.  I didn't investigate at all, so it might be a
false positive; just FYI.

	  1. Condition screen_info.capabilities & (2U /* 1 << 1 */), taking true branch.
  556        if (screen_info.capabilities & VIDEO_CAPABILITY_64BIT_BASE)
  557                base |= (u64)screen_info.ext_lfb_base << 32;
  558
  559        limit = base + size;
  560
  561        /* Does firmware framebuffer belong to us? */
	  2. Condition __b < PCI_NUM_RESOURCES, taking true branch.
	  3. Condition (r = &pdev->resource[__b]) , (__b < PCI_NUM_RESOURCES), taking true branch.
	  6. Condition __b < PCI_NUM_RESOURCES, taking true branch.
	  7. cond_at_most: Checking __b < PCI_NUM_RESOURCES implies that __b may be up to 16 on the true branch.
	  8. Condition (r = &pdev->resource[__b]) , (__b < PCI_NUM_RESOURCES), taking true branch.
	  11. incr: Incrementing __b. The value of __b may now be up to 17.
	  12. alias: Assigning: r = &pdev->resource[__b]. r may now point to as high as element 17 of pdev->resource (which consists of 17 64-byte elements).
	  13. Condition __b < PCI_NUM_RESOURCES, taking true branch.
	  14. Condition (r = &pdev->resource[__b]) , (__b < PCI_NUM_RESOURCES), taking true branch.
  562        pci_dev_for_each_resource(pdev, r) {
	  4. Condition resource_type(r) != 512, taking true branch.
	  9. Condition resource_type(r) != 512, taking true branch.

  CID 1529911 (#1 of 1): Out-of-bounds read (OVERRUN)
  15. overrun-local: Overrunning array of 1088 bytes at byte offset 1088 by dereferencing pointer r. [show details]
  563                if (resource_type(r) != IORESOURCE_MEM)
	  5. Continuing loop.
	  10. Continuing loop.
  564                        continue;