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From:   Marc Zyngier <maz@kernel.org>
To:     linux-kernel@vger.kernel.org
Cc:     chenhuacai@loongson.cn, lvjianmin@loongson.cn,
        Thomas Gleixner <tglx@linutronix.de>
Subject: [PATCH] irqchip/loongarch: Fix irq_domain_alloc_fwnode() abuse
Date:   Mon,  8 Aug 2022 11:50:20 +0100
Message-Id: <20220808105020.2689757-1-maz@kernel.org>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

The recently merged LoongArch drivers paper over the lack of
topology information by creating a bunch of fwnodes for the
irqchips. So far, so good.

However, irq_domain_alloc_fwnode() is supposed to take a PA, and
not a kernel VA blindly cast as a PA, potentially disclosing
kernel VAs to userspace. In some other cases, even NULL is used
as the PA, which is entertaining.

Fix this by using the actual PA of the block when available,
and switch to a named fwnode in the other cases.

Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 drivers/irqchip/irq-loongarch-cpu.c    | 2 +-
 drivers/irqchip/irq-loongson-eiointc.c | 3 ++-
 drivers/irqchip/irq-loongson-liointc.c | 2 +-
 drivers/irqchip/irq-loongson-pch-msi.c | 2 +-
 drivers/irqchip/irq-loongson-pch-pic.c | 2 +-
 5 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/drivers/irqchip/irq-loongarch-cpu.c b/drivers/irqchip/irq-loongarch-cpu.c
index 327f3ab62c03..741612ba6a52 100644
--- a/drivers/irqchip/irq-loongarch-cpu.c
+++ b/drivers/irqchip/irq-loongarch-cpu.c
@@ -129,7 +129,7 @@ static int __init cpuintc_acpi_init(union acpi_subtable_headers *header,
 	clear_csr_ecfg(ECFG0_IM);
 	clear_csr_estat(ESTATF_IP);
 
-	cpuintc_handle = irq_domain_alloc_fwnode(NULL);
+	cpuintc_handle = irq_domain_alloc_named_fwnode("CPUINTC");
 	irq_domain = irq_domain_create_linear(cpuintc_handle, EXCCODE_INT_NUM,
 					&loongarch_cpu_intc_irq_domain_ops, NULL);
 
diff --git a/drivers/irqchip/irq-loongson-eiointc.c b/drivers/irqchip/irq-loongson-eiointc.c
index bffb7b3128e8..16e9af8d8b1e 100644
--- a/drivers/irqchip/irq-loongson-eiointc.c
+++ b/drivers/irqchip/irq-loongson-eiointc.c
@@ -348,7 +348,8 @@ int __init eiointc_acpi_init(struct irq_domain *parent,
 	if (!priv)
 		return -ENOMEM;
 
-	priv->domain_handle = irq_domain_alloc_fwnode((phys_addr_t *)acpi_eiointc);
+	priv->domain_handle = irq_domain_alloc_named_id_fwnode("EIOPIC",
+							       acpi_eiointc->node);
 	if (!priv->domain_handle) {
 		pr_err("Unable to allocate domain handle\n");
 		goto out_free_priv;
diff --git a/drivers/irqchip/irq-loongson-liointc.c b/drivers/irqchip/irq-loongson-liointc.c
index c4f3c886ad61..acd1a4b897df 100644
--- a/drivers/irqchip/irq-loongson-liointc.c
+++ b/drivers/irqchip/irq-loongson-liointc.c
@@ -360,7 +360,7 @@ int __init liointc_acpi_init(struct irq_domain *parent, struct acpi_madt_lio_pic
 	parent_irq[0] = irq_create_mapping(parent, acpi_liointc->cascade[0]);
 	parent_irq[1] = irq_create_mapping(parent, acpi_liointc->cascade[1]);
 
-	domain_handle = irq_domain_alloc_fwnode((phys_addr_t *)acpi_liointc);
+	domain_handle = irq_domain_alloc_fwnode(&acpi_liointc->address);
 	if (!domain_handle) {
 		pr_err("Unable to allocate domain handle\n");
 		return -ENOMEM;
diff --git a/drivers/irqchip/irq-loongson-pch-msi.c b/drivers/irqchip/irq-loongson-pch-msi.c
index d0e8551bebfa..a72ede90ffc6 100644
--- a/drivers/irqchip/irq-loongson-pch-msi.c
+++ b/drivers/irqchip/irq-loongson-pch-msi.c
@@ -282,7 +282,7 @@ int __init pch_msi_acpi_init(struct irq_domain *parent,
 	int ret;
 	struct fwnode_handle *domain_handle;
 
-	domain_handle = irq_domain_alloc_fwnode((phys_addr_t *)acpi_pchmsi);
+	domain_handle = irq_domain_alloc_fwnode(&acpi_pchmsi->msg_address);
 	ret = pch_msi_init(acpi_pchmsi->msg_address, acpi_pchmsi->start,
 				acpi_pchmsi->count, parent, domain_handle);
 	if (ret < 0)
diff --git a/drivers/irqchip/irq-loongson-pch-pic.c b/drivers/irqchip/irq-loongson-pch-pic.c
index b987b6517d59..c01b9c257005 100644
--- a/drivers/irqchip/irq-loongson-pch-pic.c
+++ b/drivers/irqchip/irq-loongson-pch-pic.c
@@ -349,7 +349,7 @@ int __init pch_pic_acpi_init(struct irq_domain *parent,
 
 	vec_base = acpi_pchpic->gsi_base - GSI_MIN_PCH_IRQ;
 
-	domain_handle = irq_domain_alloc_fwnode((phys_addr_t *)acpi_pchpic);
+	domain_handle = irq_domain_alloc_fwnode(&acpi_pchpic->address);
 	if (!domain_handle) {
 		pr_err("Unable to allocate domain handle\n");
 		return -ENOMEM;
-- 
2.34.1