From: Thomas Gleixner <tglx@linutronix.de>
Date: Thu, 9 Jul 2020 11:53:06 +0200
Patch-mainline: v5.8-rc6
Subject: irqdomain/treewide: Keep firmware node unconditionally allocated
Git-commit: e3beca48a45b5e0e6e6a4e0124276b8248dcc9bb
References: git-fixes bsc#1180889

Quite some non OF/ACPI users of irqdomains allocate firmware nodes of type
IRQCHIP_FWNODE_NAMED or IRQCHIP_FWNODE_NAMED_ID and free them right after
creating the irqdomain. The only purpose of these FW nodes is to convey
name information. When this was introduced the core code did not store the
pointer to the node in the irqdomain. A recent change stored the firmware
node pointer in irqdomain for other reasons and missed to notice that the
usage sites which do the alloc_fwnode/create_domain/free_fwnode sequence
are broken by this. Storing a dangling pointer is dangerous itself, but in
case that the domain is destroyed later on this leads to a double free.

Remove the freeing of the firmware node after creating the irqdomain from
all affected call sites to cure this.

Fixes: 711419e504eb ("irqdomain: Add the missing assignment of domain->fwnode for named fwnode")
Reported-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/873661qakd.fsf@nanos.tec.linutronix.de
Acked-by: Olaf Hering <ohering@suse.de>
---
 arch/mips/pci/pci-xtalk-bridge.c    |    5 +++--
 arch/x86/kernel/apic/io_apic.c      |   10 +++++-----
 arch/x86/kernel/apic/msi.c          |   16 +++++++++++-----
 arch/x86/kernel/apic/vector.c       |    1 -
 arch/x86/platform/uv/uv_irq.c       |    3 ++-
 drivers/iommu/amd_iommu.c           |    5 +++--
 drivers/iommu/hyperv-iommu.c        |    5 ++++-
 drivers/iommu/intel_irq_remapping.c |    2 +-
 drivers/pci/controller/vmd.c        |    5 +++--
 9 files changed, 32 insertions(+), 20 deletions(-)

--- a/arch/mips/pci/pci-xtalk-bridge.c
+++ b/arch/mips/pci/pci-xtalk-bridge.c
@@ -488,9 +488,10 @@ static int bridge_probe(struct platform_
 		return -ENOMEM;
 	domain = irq_domain_create_hierarchy(parent, 0, 8, fn,
 					     &bridge_domain_ops, NULL);
-	irq_domain_free_fwnode(fn);
-	if (!domain)
+	if (!domain) {
+		irq_domain_free_fwnode(fn);
 		return -ENOMEM;
+	}
 
 	pci_set_flags(PCI_PROBE_ONLY);
 
--- a/arch/x86/kernel/apic/io_apic.c
+++ b/arch/x86/kernel/apic/io_apic.c
@@ -2329,12 +2329,12 @@ static int mp_irqdomain_create(int ioapi
 	ip->irqdomain = irq_domain_create_linear(fn, hwirqs, cfg->ops,
 						 (void *)(long)ioapic);
 
-	/* Release fw handle if it was allocated above */
-	if (!cfg->dev)
-		irq_domain_free_fwnode(fn);
-
-	if (!ip->irqdomain)
+	if (!ip->irqdomain) {
+		/* Release fw handle if it was allocated above */
+		if (!cfg->dev)
+			irq_domain_free_fwnode(fn);
 		return -ENOMEM;
+	}
 
 	ip->irqdomain->parent = parent;
 
--- a/arch/x86/kernel/apic/msi.c
+++ b/arch/x86/kernel/apic/msi.c
@@ -262,12 +262,13 @@ void __init arch_init_msi_domain(struct
 		msi_default_domain =
 			pci_msi_create_irq_domain(fn, &pci_msi_domain_info,
 						  parent);
-		irq_domain_free_fwnode(fn);
 	}
-	if (!msi_default_domain)
+	if (!msi_default_domain) {
+		irq_domain_free_fwnode(fn);
 		pr_warn("failed to initialize irqdomain for MSI/MSI-x.\n");
-	else
+	} else {
 		msi_default_domain->flags |= IRQ_DOMAIN_MSI_NOMASK_QUIRK;
+	}
 }
 
 #ifdef CONFIG_IRQ_REMAP
@@ -300,7 +301,8 @@ struct irq_domain *arch_create_remap_msi
 	if (!fn)
 		return NULL;
 	d = pci_msi_create_irq_domain(fn, &pci_msi_ir_domain_info, parent);
-	irq_domain_free_fwnode(fn);
+	if (!d)
+		irq_domain_free_fwnode(fn);
 	return d;
 }
 #endif
@@ -363,7 +365,8 @@ static struct irq_domain *dmar_get_irq_d
 	if (fn) {
 		dmar_domain = msi_create_irq_domain(fn, &dmar_msi_domain_info,
 						    x86_vector_domain);
-		irq_domain_free_fwnode(fn);
+		if (!dmar_domain)
+			irq_domain_free_fwnode(fn);
 	}
 out:
 	mutex_unlock(&dmar_lock);
@@ -488,7 +491,10 @@ struct irq_domain *hpet_create_irq_domai
 	}
 
 	d = msi_create_irq_domain(fn, domain_info, parent);
-	irq_domain_free_fwnode(fn);
+	if (!d) {
+		irq_domain_free_fwnode(fn);
+		kfree(domain_info);
+	}
 	return d;
 }
 
--- a/arch/x86/kernel/apic/vector.c
+++ b/arch/x86/kernel/apic/vector.c
@@ -703,7 +703,6 @@ int __init arch_early_irq_init(void)
 	x86_vector_domain = irq_domain_create_tree(fn, &x86_vector_domain_ops,
 						   NULL);
 	BUG_ON(x86_vector_domain == NULL);
-	irq_domain_free_fwnode(fn);
 	irq_set_default_host(x86_vector_domain);
 
 	arch_init_msi_domain(x86_vector_domain);
--- a/arch/x86/platform/uv/uv_irq.c
+++ b/arch/x86/platform/uv/uv_irq.c
@@ -167,9 +167,10 @@ static struct irq_domain *uv_get_irq_dom
 		goto out;
 
 	uv_domain = irq_domain_create_tree(fn, &uv_domain_ops, NULL);
-	irq_domain_free_fwnode(fn);
 	if (uv_domain)
 		uv_domain->parent = x86_vector_domain;
+	else
+		irq_domain_free_fwnode(fn);
 out:
 	mutex_unlock(&uv_lock);
 
--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -4677,9 +4677,10 @@ int amd_iommu_create_irq_domain(struct a
 	if (!fn)
 		return -ENOMEM;
 	iommu->ir_domain = irq_domain_create_tree(fn, &amd_ir_domain_ops, iommu);
-	irq_domain_free_fwnode(fn);
-	if (!iommu->ir_domain)
+	if (!iommu->ir_domain) {
+		irq_domain_free_fwnode(fn);
 		return -ENOMEM;
+	}
 
 	iommu->ir_domain->parent = arch_get_ir_parent_domain();
 	iommu->msi_domain = arch_create_remap_msi_irq_domain(iommu->ir_domain,
--- a/drivers/iommu/hyperv-iommu.c
+++ b/drivers/iommu/hyperv-iommu.c
@@ -155,7 +155,10 @@ static int __init hyperv_prepare_irq_rem
 				0, IOAPIC_REMAPPING_ENTRY, fn,
 				&hyperv_ir_domain_ops, NULL);
 
-	irq_domain_free_fwnode(fn);
+	if (!ioapic_ir_domain) {
+		irq_domain_free_fwnode(fn);
+		return -ENOMEM;
+	}
 
 	/*
 	 * Hyper-V doesn't provide irq remapping function for
--- a/drivers/iommu/intel_irq_remapping.c
+++ b/drivers/iommu/intel_irq_remapping.c
@@ -563,8 +563,8 @@ static int intel_setup_irq_remapping(str
 					    0, INTR_REMAP_TABLE_ENTRIES,
 					    fn, &intel_ir_domain_ops,
 					    iommu);
-	irq_domain_free_fwnode(fn);
 	if (!iommu->ir_domain) {
+		irq_domain_free_fwnode(fn);
 		pr_err("IR%d: failed to allocate irqdomain\n", iommu->seq_id);
 		goto out_free_bitmap;
 	}
--- a/drivers/pci/controller/vmd.c
+++ b/drivers/pci/controller/vmd.c
@@ -680,9 +680,10 @@ static int vmd_enable_domain(struct vmd_
 
 	vmd->irq_domain = pci_msi_create_irq_domain(fn, &vmd_msi_domain_info,
 						    x86_vector_domain);
-	irq_domain_free_fwnode(fn);
-	if (!vmd->irq_domain)
+	if (!vmd->irq_domain) {
+		irq_domain_free_fwnode(fn);
 		return -ENODEV;
+	}
 
 	pci_add_resource(&resources, &vmd->resources[0]);
 	pci_add_resource_offset(&resources, &vmd->resources[1], offset[0]);