The patch below does not apply to the 4.19-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From a740a423c36932695b01a3e920f697bc55b05fec Mon Sep 17 00:00:00 2001
From: Thomas Gleixner tglx@linutronix.de Date: Fri, 6 Mar 2020 14:03:42 +0100 Subject: [PATCH] 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 a949bd39e343..d44c8fd17609 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;