linux-kernel - [PATCH v2] PCI : Fix pcie_flag_reg in set_pcie_port

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>] [thread-next>] [day] [month] [year] [list]

Message-ID: <20241213070241.3334854-1-gthiagarajan@marvell.com>
Date: Fri, 13 Dec 2024 12:32:41 +0530
From: Gowthami Thiagarajan <gthiagarajan@...vell.com>
To: <bhelgaas@...gle.com>, <linux-pci@...r.kernel.org>,
        <linux-kernel@...r.kernel.org>
CC: Gowthami Thiagarajan <gthiagarajan@...vell.com>
Subject: [PATCH v2] PCI : Fix pcie_flag_reg in set_pcie_port_type

When an invalid PCIe topology is detected, the set_pcie_port_type function 
does not set the port type correctly. This issue can occur in 
configurations such as:

	Root Port ---> Downstream Port ---> Root Port

In such cases, the topology is identified as invalid and due to the incorrect 
port type setting, the extended configuration space of the child device becomes 
inaccessible.

Signed-off-by: Gowthami Thiagarajan <gthiagarajan@...vell.com>
---
v1->v2:
	Updated commit description

 drivers/pci/probe.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 4f68414c3086..263ec21451d9 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -1596,7 +1596,7 @@ void set_pcie_port_type(struct pci_dev *pdev)
 		if (pcie_downstream_port(parent)) {
 			pci_info(pdev, "claims to be downstream port but is acting as upstream port, correcting type\n");
 			pdev->pcie_flags_reg &= ~PCI_EXP_FLAGS_TYPE;
-			pdev->pcie_flags_reg |= PCI_EXP_TYPE_UPSTREAM;
+			pdev->pcie_flags_reg |= PCI_EXP_TYPE_UPSTREAM << 4;
 		}
 	} else if (type == PCI_EXP_TYPE_UPSTREAM) {
 		/*
@@ -1607,7 +1607,7 @@ void set_pcie_port_type(struct pci_dev *pdev)
 		if (pci_pcie_type(parent) == PCI_EXP_TYPE_UPSTREAM) {
 			pci_info(pdev, "claims to be upstream port but is acting as downstream port, correcting type\n");
 			pdev->pcie_flags_reg &= ~PCI_EXP_FLAGS_TYPE;
-			pdev->pcie_flags_reg |= PCI_EXP_TYPE_DOWNSTREAM;
+			pdev->pcie_flags_reg |= PCI_EXP_TYPE_DOWNSTREAM << 4;
 		}
 	}
 }
-- 
2.25.1