Commit 59c39840 authored Mar 24, 2019 by Prasad Sodagudi Committed by Thomas Gleixner Mar 24, 2019

genirq: Prevent use-after-free and work list corruption



When irq_set_affinity_notifier() replaces the notifier, then the
reference count on the old notifier is dropped which causes it to be
freed. But nothing ensures that the old notifier is not longer queued
in the work list. If it is queued this results in a use after free and
possibly in work list corruption.

Ensure that the work is canceled before the reference is dropped.

Signed-off-by: Prasad Sodagudi <psodagud@codeaurora.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: marc.zyngier@arm.com
Link: https://lkml.kernel.org/r/1553439424-6529-1-git-send-email-psodagud@codeaurora.org

parent 8c2ffd91

kernel/irq/manage.c

+3 −1

Original line number	Diff line number	Diff line
		@@ -357,8 +357,10 @@ irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify)
		desc->affinity_notify = notify;
		raw_spin_unlock_irqrestore(&desc->lock, flags);

		if (old_notify)
		if (old_notify) {
		cancel_work_sync(&old_notify->work);
		kref_put(&old_notify->kref, old_notify->release);
		}

		return 0;
		}

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