linux-kernel - [PATCH] PCI/MSI: Fix MSI IRQ domains for SR-IOV

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: <20150918210648.19363.35694.stgit@gimli.home>
Date:	Fri, 18 Sep 2015 15:08:54 -0600
From:	Alex Williamson <alex.williamson@...hat.com>
To:	linux-pci@...r.kernel.org
Cc:	bhelgaas@...gle.com, marc.zyngier@....com, tglx@...utronix.de,
	linux-kernel@...r.kernel.org
Subject: [PATCH] PCI/MSI: Fix MSI IRQ domains for SR-IOV

SR-IOV creates a virtual bus where bus->self is NULL.  This results
in a segfault as VFs are added and we scan for an MSI domain without
taking that into account.  Detect this and scan up to the parent bus
until we find a real bridge.

Fixes: 44aa0c657e3e ("PCI/MSI: Add hooks to populate the msi_domain field")
Signed-off-by: Alex Williamson <alex.williamson@...hat.com>
---
 drivers/pci/probe.c |   17 +++++++++++------
 1 file changed, 11 insertions(+), 6 deletions(-)

diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 0b2be17..b42419e 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -676,15 +676,20 @@ static struct irq_domain *pci_host_bridge_msi_domain(struct pci_bus *bus)
 static void pci_set_bus_msi_domain(struct pci_bus *bus)
 {
 	struct irq_domain *d;
+	struct pci_bus *b;
 
 	/*
-	 * Either bus is the root, and we must obtain it from the
-	 * firmware, or we inherit it from the bridge device.
+	 * The bus can be a root bus, a subordinate bus, or a virtual bus
+	 * created by an SR-IOV device.  Walk up to the first bridge device
+	 * found or derive the domain from the host bridge.
 	 */
-	if (pci_is_root_bus(bus))
-		d = pci_host_bridge_msi_domain(bus);
-	else
-		d = dev_get_msi_domain(&bus->self->dev);
+	for (b = bus, d = NULL; !d && !pci_is_root_bus(b); b = b->parent) {
+		if (b->self)
+			d = dev_get_msi_domain(&b->self->dev);
+	}
+
+	if (!d)
+		d = pci_host_bridge_msi_domain(b);
 
 	dev_set_msi_domain(&bus->dev, d);
 }

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/