[PATCH][V2] PCI: Fix a potential uninitentional integer overflow issue

From: Colin King
Date: Tue Nov 10 2020 - 17:11:00 EST


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>
---

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",
--
2.28.0