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Subject: Re: KASAN: slab-out-of-bounds Read in handle_vmptrld
To:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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From:   Paolo Bonzini <pbonzini@redhat.com>
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Date:   Fri, 13 Sep 2019 17:01:22 +0200
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On 13/09/19 15:02, Greg Kroah-Hartman wrote:
> Look at linux-next, we "should" have fixed up hcd_buffer_alloc() now to
> not need this type of thing.  If we got it wrong, please let us know and
> then yes, a fix like this would be most appreciated :)

I still see

	/* some USB hosts just use PIO */
	if (!hcd_uses_dma(hcd)) {
		*dma = ~(dma_addr_t) 0;
		return kmalloc(size, mem_flags);
	}

in linux-next's hcd_buffer_alloc and also in usb.git's usb-next branch.
 I also see the same

	if (remap_pfn_range(vma, vma->vm_start,
			virt_to_phys(usbm->mem) >> PAGE_SHIFT,
			size, vma->vm_page_prot) < 0) {
		...
	}

in usbdev_mmap.  Of course it's possible that I'm looking at the wrong
branch, or just being dense.

Paolo