Commit 6d7483c6 authored Nov 05, 2020 by Bjorn Helgaas Committed by Greg Kroah-Hartman Dec 30, 2020

PCI: Bounds-check command-line resource alignment requests

[ Upstream commit 6534aac198b58309ff2337981d3f893e0be1d19d ]

32-bit BARs are limited to 2GB size (2^31).  By extension, I assume 64-bit
BARs are limited to 2^63 bytes.  Limit the alignment requested by the
"pci=resource_alignment=" command-line parameter to 2^63.

Link: https://lore.kernel.org/r/20201007123045.GS4282@kadam


Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

parent 4763ddb8

drivers/pci/pci.c

+8 −6

Original line number	Diff line number	Diff line
		@@ -5842,16 +5842,18 @@ static resource_size_t pci_specified_resource_alignment(struct pci_dev *dev,
		if (sscanf(p, "%d%n", &align_order, &count) == 1 &&
		p[count] == '@') {
		p += count + 1;
		if (align_order > 63) {
		pr_err("PCI: Invalid requested alignment (order %d)\n",
		align_order);
		align_order = PAGE_SHIFT;
		}
		} else {
		align_order = -1;
		align_order = PAGE_SHIFT;
		}

		ret = pci_dev_str_match(dev, p, &p);
		if (ret == 1) {
		*resize = true;
		if (align_order == -1)
		align = PAGE_SIZE;
		else
		align = 1 << align_order;
		break;
		} else if (ret < 0) {