[PATCH] irqdomain: check irq mapping against domain size

[Ben Dooks]

The irq translate code does not check the irq number against
the maximum a domain can handle. This can cause an OOPS if
the firmware data has been damaged in any way. Check the intspec
or fwdata against the irqdomain and return -EINVAL if over.

This is the result of bug somewhere in the boot of a SiFive Unmatched
board where the 5th argument of the pcie node is being damaged which
causes an OOPS in the startup code.

Signed-off-by: Ben Dooks <ben.dooks@xxxxxxxxxxxxxxx>
---
 kernel/irq/irqdomain.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c
index 6284443b87ec..e61397420723 100644
--- a/kernel/irq/irqdomain.c
+++ b/kernel/irq/irqdomain.c
@@ -906,6 +906,8 @@ int irq_domain_xlate_onecell(struct irq_domain *d, struct device_node *ctrlr,
 {
 	if (WARN_ON(intsize < 1))
 		return -EINVAL;
+	if (WARN_ON(intspec[0] > d->hwirq_max))
+		return -EINVAL;
 	*out_hwirq = intspec[0];
 	*out_type = IRQ_TYPE_NONE;
 	return 0;
@@ -948,6 +950,8 @@ int irq_domain_xlate_onetwocell(struct irq_domain *d,
 {
 	if (WARN_ON(intsize < 1))
 		return -EINVAL;
+	if (WARN_ON(intspec[0] > d->hwirq_max))
+		return -EINVAL;
 	*out_hwirq = intspec[0];
 	if (intsize > 1)
 		*out_type = intspec[1] & IRQ_TYPE_SENSE_MASK;
@@ -973,6 +977,8 @@ int irq_domain_translate_onecell(struct irq_domain *d,
 {
 	if (WARN_ON(fwspec->param_count < 1))
 		return -EINVAL;
+	if (WARN_ON(fwspec->param[0] > d->hwirq_max))
+		return -EINVAL;
 	*out_hwirq = fwspec->param[0];
 	*out_type = IRQ_TYPE_NONE;
 	return 0;
@@ -994,6 +1000,8 @@ int irq_domain_translate_twocell(struct irq_domain *d,
 {
 	if (WARN_ON(fwspec->param_count < 2))
 		return -EINVAL;
+	if (WARN_ON(fwspec->param[0] > d->hwirq_max))
+		return -EINVAL;
 	*out_hwirq = fwspec->param[0];
 	*out_type = fwspec->param[1] & IRQ_TYPE_SENSE_MASK;
 	return 0;
-- 
2.30.2