[PATCH] irqdomain/treewide: Keep firmware node unconditionally allocated

[PATCH] irqdomain/treewide: Keep firmware node unconditionally allocated

[Thomas Gleixner]

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>
Cc: stable@vger.kernel.org

---
 arch/mips/pci/pci-xtalk-bridge.c    |    5 +++--
 arch/x86/kernel/apic/io_apic.c      |   10 +++++-----
 arch/x86/kernel/apic/msi.c          |   18 ++++++++++++------
 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/mfd/ioc3.c                  |    5 +++--
 drivers/pci/controller/vmd.c        |    5 +++--
 10 files changed, 36 insertions(+), 23 deletions(-)

--- a/arch/mips/pci/pci-xtalk-bridge.c
+++ b/arch/mips/pci/pci-xtalk-bridge.c
@@ -627,9 +627,10 @@ 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
@@ -2316,12 +2316,12 @@ 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
@@ -263,12 +263,13 @@ 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
@@ -301,7 +302,8 @@ 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
@@ -364,7 +366,8 @@ 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);
@@ -489,7 +492,10 @@ 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
@@ -709,7 +709,6 @@ 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
@@ -3985,9 +3985,10 @@ 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/mfd/ioc3.c
+++ b/drivers/mfd/ioc3.c
@@ -142,10 +142,11 @@ static int ioc3_irq_domain_setup(struct
 		goto err;
 
 	domain = irq_domain_create_linear(fn, 24, &ioc3_irq_domain_ops, ipd);
-	if (!domain)
+	if (!domain) {
+		irq_domain_free_fwnode(fn);
 		goto err;
+	}
 
-	irq_domain_free_fwnode(fn);
 	ipd->domain = domain;
 
 	irq_set_chained_handler_and_data(irq, ioc3_irq_handler, domain);
--- a/drivers/pci/controller/vmd.c
+++ b/drivers/pci/controller/vmd.c
@@ -546,9 +546,10 @@ 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]);

Re: [PATCH] irqdomain/treewide: Keep firmware node unconditionally allocated

[Marc Zyngier]

Hi Thomas,

Catching up on email...

On 2020-07-09 10:53, Thomas Gleixner wrote:
> 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>
> Cc: stable@vger.kernel.org

Urgh, that's pretty disastrous. My bad. Thanks a lot for having
put this patch together.

Acked-by: Marc Zyngier <maz@kernel.org>

If you can take it directly into Linus' tree, that'd be greatly
appreciated.

Thanks again,

         M.
-- 
Jazz is not dead. It just smells funny...

Re: [PATCH] irqdomain/treewide: Keep firmware node unconditionally allocated

[Bjorn Helgaas]

On Thu, Jul 09, 2020 at 11:53:06AM +0200, Thomas Gleixner wrote:
> 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>
> Cc: stable@vger.kernel.org

Acked-by: Bjorn Helgaas <bhelgaas@google.com>	# drivers/pci/

[tip: irq/urgent] irqdomain/treewide: Keep firmware node unconditionally allocated

[tip-bot2 for Thomas Gleixner]

The following commit has been merged into the irq/urgent branch of tip:

Commit-ID:     e3beca48a45b5e0e6e6a4e0124276b8248dcc9bb
Gitweb:        https://git.kernel.org/tip/e3beca48a45b5e0e6e6a4e0124276b8248dcc9bb
Author:        Thomas Gleixner <tglx@linutronix.de>
AuthorDate:    Thu, 09 Jul 2020 11:53:06 +02:00
Committer:     Thomas Gleixner <tglx@linutronix.de>
CommitterDate: Tue, 14 Jul 2020 17:44:42 +02:00

irqdomain/treewide: Keep firmware node unconditionally allocated

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

---
 arch/mips/pci/pci-xtalk-bridge.c    |  5 +++--
 arch/x86/kernel/apic/io_apic.c      | 10 +++++-----
 arch/x86/kernel/apic/msi.c          | 18 ++++++++++++------
 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/mfd/ioc3.c                  |  5 +++--
 drivers/pci/controller/vmd.c        |  5 +++--
 10 files changed, 36 insertions(+), 23 deletions(-)

diff --git a/arch/mips/pci/pci-xtalk-bridge.c b/arch/mips/pci/pci-xtalk-bridge.c
index 3b2552f..5958217 100644
--- a/arch/mips/pci/pci-xtalk-bridge.c
+++ b/arch/mips/pci/pci-xtalk-bridge.c
@@ -627,9 +627,10 @@ static int bridge_probe(struct platform_device *pdev)
 		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);
 
diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
index ce61e3e..81ffcfb 100644
--- a/arch/x86/kernel/apic/io_apic.c
+++ b/arch/x86/kernel/apic/io_apic.c
@@ -2316,12 +2316,12 @@ static int mp_irqdomain_create(int ioapic)
 	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;
 
diff --git a/arch/x86/kernel/apic/msi.c b/arch/x86/kernel/apic/msi.c
index 5cbaca5..c2b2911 100644
--- a/arch/x86/kernel/apic/msi.c
+++ b/arch/x86/kernel/apic/msi.c
@@ -263,12 +263,13 @@ void __init arch_init_msi_domain(struct irq_domain *parent)
 		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
@@ -301,7 +302,8 @@ struct irq_domain *arch_create_remap_msi_irq_domain(struct irq_domain *parent,
 	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
@@ -364,7 +366,8 @@ static struct irq_domain *dmar_get_irq_domain(void)
 	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);
@@ -489,7 +492,10 @@ struct irq_domain *hpet_create_irq_domain(int hpet_id)
 	}
 
 	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;
 }
 
diff --git a/arch/x86/kernel/apic/vector.c b/arch/x86/kernel/apic/vector.c
index c48be6e..cc8b16f 100644
--- a/arch/x86/kernel/apic/vector.c
+++ b/arch/x86/kernel/apic/vector.c
@@ -709,7 +709,6 @@ 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);
diff --git a/arch/x86/platform/uv/uv_irq.c b/arch/x86/platform/uv/uv_irq.c
index fc13cbb..abb6075 100644
--- 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_domain(void)
 		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);
 
diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c
index 74cca17..2f22326 100644
--- a/drivers/iommu/amd/iommu.c
+++ b/drivers/iommu/amd/iommu.c
@@ -3985,9 +3985,10 @@ int amd_iommu_create_irq_domain(struct amd_iommu *iommu)
 	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,
diff --git a/drivers/iommu/hyperv-iommu.c b/drivers/iommu/hyperv-iommu.c
index 3c0c67a..8919c1c 100644
--- a/drivers/iommu/hyperv-iommu.c
+++ b/drivers/iommu/hyperv-iommu.c
@@ -155,7 +155,10 @@ static int __init hyperv_prepare_irq_remapping(void)
 				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
diff --git a/drivers/iommu/intel/irq_remapping.c b/drivers/iommu/intel/irq_remapping.c
index 7f87698..9564d23 100644
--- a/drivers/iommu/intel/irq_remapping.c
+++ b/drivers/iommu/intel/irq_remapping.c
@@ -563,8 +563,8 @@ static int intel_setup_irq_remapping(struct intel_iommu *iommu)
 					    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;
 	}
diff --git a/drivers/mfd/ioc3.c b/drivers/mfd/ioc3.c
index 02998d4..74cee7c 100644
--- a/drivers/mfd/ioc3.c
+++ b/drivers/mfd/ioc3.c
@@ -142,10 +142,11 @@ static int ioc3_irq_domain_setup(struct ioc3_priv_data *ipd, int irq)
 		goto err;
 
 	domain = irq_domain_create_linear(fn, 24, &ioc3_irq_domain_ops, ipd);
-	if (!domain)
+	if (!domain) {
+		irq_domain_free_fwnode(fn);
 		goto err;
+	}
 
-	irq_domain_free_fwnode(fn);
 	ipd->domain = domain;
 
 	irq_set_chained_handler_and_data(irq, ioc3_irq_handler, domain);
diff --git a/drivers/pci/controller/vmd.c b/drivers/pci/controller/vmd.c
index e386d4e..9a64cf9 100644
--- a/drivers/pci/controller/vmd.c
+++ b/drivers/pci/controller/vmd.c
@@ -546,9 +546,10 @@ static int vmd_enable_domain(struct vmd_dev *vmd, unsigned long features)
 
 	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]);