[V2] genirq: Check irq_data_get_irq_chip() return value before use

Commit Message

Marek Vasut May 14, 2020, 12:25 a.m. UTC

The irq_data_get_irq_chip() can return NULL, however it is expected
that this never happens. If a buggy driver leads to a NULL being
returned from irq_data_get_irq_chip(), warn about it.

Signed-off-by: Marek Vasut <[e-mail]>
Cc: Linus Walleij <[e-mail]>
Cc: Marc Zyngier <[e-mail]>
Cc: Stephen Boyd <[e-mail]>
Cc: Thomas Gleixner <[e-mail]>
To: [e-mail]
---
V2: - Use WARN_ON_ONCE() and return -ENODEV
    - Reword the commit message
---
 kernel/irq/manage.c | 4 ++++
 1 file changed, 4 insertions(+)

Patch

diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index 453a8a0f4804..761911168438 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -2619,6 +2619,8 @@  int __irq_get_irqchip_state(struct irq_data *data, enum irqchip_irq_state which,
 
 	do {
 		chip = irq_data_get_irq_chip(data);
+		if (WARN_ON_ONCE(!chip))
+			return -ENODEV;
 		if (chip->irq_get_irqchip_state)
 			break;
 #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
@@ -2696,6 +2698,8 @@  int irq_set_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
 
 	do {
 		chip = irq_data_get_irq_chip(data);
+		if (WARN_ON_ONCE(!chip))
+			return -ENODEV;
 		if (chip->irq_set_irqchip_state)
 			break;
 #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY