genirq/debugfs: Add missing sanity checks to interrupt injection
Interrupts cannot be injected when the interrupt is not activated and when
a replay is already in progress.
Fixes: 536e2e34bd00 ("genirq/debugfs: Triggering of interrupts from userspace")
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Marc Zyngier <maz@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20200306130623.500019114@linutronix.de
diff --git a/kernel/irq/debugfs.c b/kernel/irq/debugfs.c
index a949bd3..d44c8fd 100644
--- a/kernel/irq/debugfs.c
+++ b/kernel/irq/debugfs.c
@@ -206,8 +206,15 @@ static ssize_t irq_debug_write(struct file *file, const char __user *user_buf,
chip_bus_lock(desc);
raw_spin_lock_irqsave(&desc->lock, flags);
- if (irq_settings_is_level(desc) || desc->istate & IRQS_NMI) {
- /* Can't do level nor NMIs, sorry */
+ /*
+ * Don't allow injection when the interrupt is:
+ * - Level or NMI type
+ * - not activated
+ * - replaying already
+ */
+ if (irq_settings_is_level(desc) ||
+ !irqd_is_activated(&desc->irq_data) ||
+ (desc->istate & (IRQS_NMI | IRQS_REPLAY))) {
err = -EINVAL;
} else {
desc->istate |= IRQS_PENDING;
