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

[ Upstream commit 59c39840f5abf4a71e1810a8da71aaccd6c17d26 ]

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
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index e7ef539c56d970fad798ef3b9cf5d9802e8b1b4f..749280b58080fb78fdd1cc6a40551eccf68b07b2 100644 (file)
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -307,8 +307,10 @@ 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;
 }