[+cc Dan]
On Tue, Nov 10, 2020 at 10:10:48PM +0000, Colin King wrote:
> From: Colin Ian King <colin.king@xxxxxxxxxxxxx>
>
> The shift of 1 by align_order is evaluated using 32 bit arithmetic
> and the result is assigned to a resource_size_t type variable that
> is a 64 bit unsigned integer on 64 bit platforms. Fix an overflow
> before widening issue by making the 1 a ULL.
>
> Addresses-Coverity: ("Unintentional integer overflow")
> Fixes: 07d8d7e57c28 ("PCI: Make specifying PCI devices in kernel parameters reusable")
> Signed-off-by: Colin Ian King <colin.king@xxxxxxxxxxxxx>
Applied to pci/misc for v5.11 with Logan's Reviewed-by and also the
Fixes: correction.
I first applied the patch below to bounds-check the alignment as noted
by Dan.
> ---
>
> V2: Use ULL instead of BIT_ULL(), fix spelling mistake and capitalize first
> word of patch subject.
>
> ---
> drivers/pci/pci.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
> index 3ef63a101fa1..248044a7ef8c 100644
> --- a/drivers/pci/pci.c
> +++ b/drivers/pci/pci.c
> @@ -6214,7 +6214,7 @@ static resource_size_t pci_specified_resource_alignment(struct pci_dev *dev,
> if (align_order == -1)
> align = PAGE_SIZE;
> else
> - align = 1 << align_order;
> + align = 1ULL << align_order;
> break;
> } else if (ret < 0) {
> pr_err("PCI: Can't parse resource_alignment parameter: %s\n",
commit d6ca242c448f ("PCI: Bounds-check command-line resource alignment requests")
Author: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
Date: Thu Nov 5 14:51:36 2020 -0600
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 <dan.carpenter@xxxxxxxxxx>
Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 8b9bea8ba751..26c1b2d0bacd 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -6197,19 +6197,21 @@ 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",
