linux-kernel - [PATCH v1] PCI: Cadence: Avoid possible signed 64-bit truncation

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [day] [month] [year] [list]

Message-ID: <20251209223756.2321578-1-irogers@google.com>
Date: Tue,  9 Dec 2025 14:37:56 -0800
From: Ian Rogers <irogers@...gle.com>
To: Lorenzo Pieralisi <lpieralisi@...nel.org>, 
	"Krzysztof Wilczyński" <kwilczynski@...nel.org>, Manivannan Sadhasivam <mani@...nel.org>, Rob Herring <robh@...nel.org>, 
	Bjorn Helgaas <bhelgaas@...gle.com>, Siddharth Vadapalli <s-vadapalli@...com>, 
	Kishon Vijay Abraham I <kishon@...nel.org>, Hans Zhang <18255117159@....com>, 
	Chen Wang <unicorn_wang@...look.com>, Ian Rogers <irogers@...gle.com>, linux-pci@...r.kernel.org, 
	linux-kernel@...r.kernel.org
Subject: [PATCH v1] PCI: Cadence: Avoid possible signed 64-bit truncation

64-bit truncation to 32-bit can result in the sign of the truncated
value changing. The cdns_pcie_host_dma_ranges_cmp is used in list_sort
and so the truncation could result in an invalid sort order. This
would only happen were the resource_size values large.

Signed-off-by: Ian Rogers <irogers@...gle.com>
---
 drivers/pci/controller/cadence/pcie-cadence-host.c | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/drivers/pci/controller/cadence/pcie-cadence-host.c b/drivers/pci/controller/cadence/pcie-cadence-host.c
index fffd63d6665e..e5fd02305ab6 100644
--- a/drivers/pci/controller/cadence/pcie-cadence-host.c
+++ b/drivers/pci/controller/cadence/pcie-cadence-host.c
@@ -414,11 +414,19 @@ static int cdns_pcie_host_dma_ranges_cmp(void *priv, const struct list_head *a,
 					 const struct list_head *b)
 {
 	struct resource_entry *entry1, *entry2;
+	u64 size1, size2;
 
-        entry1 = container_of(a, struct resource_entry, node);
-        entry2 = container_of(b, struct resource_entry, node);
+	entry1 = container_of(a, struct resource_entry, node);
+	entry2 = container_of(b, struct resource_entry, node);
 
-        return resource_size(entry2->res) - resource_size(entry1->res);
+	size1 = resource_size(entry1->res);
+	size2 = resource_size(entry2->res);
+
+	if (size1 > size2)
+		return -1;
+	if (size1 < size2)
+		return 1;
+	return 0;
 }
 
 static void cdns_pcie_host_unmap_dma_ranges(struct cdns_pcie_rc *rc)
-- 
2.52.0.223.gf5cc29aaa4-goog