From 6534aac198b58309ff2337981d3f893e0be1d19d Mon Sep 17 00:00:00 2001 From: Bjorn Helgaas Date: Thu, 5 Nov 2020 14:51:36 -0600 Subject: [PATCH] PCI: Bounds-check command-line resource alignment requests 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 Signed-off-by: Bjorn Helgaas --- drivers/pci/pci.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 3ef63a101fa1..711268776371 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -6202,19 +6202,21 @@ static resource_size_t pci_specified_resource_alignment(struct pci_dev *dev, while (*p) { count = 0; if (sscanf(p, "%d%n", &align_order, &count) == 1 && - p[count] == '@') { + 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; + align = 1 << align_order; break; } else if (ret < 0) { pr_err("PCI: Can't parse resource_alignment parameter: %s\n",