From: Prasad Sodagudi Date: Sun, 24 Mar 2019 14:57:04 +0000 (-0700) Subject: genirq: Prevent use-after-free and work list corruption X-Git-Tag: v5.2-rc1~207^2~4 X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=59c39840f5abf4a71e1810a8da71aaccd6c17d26;p=linux.git 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 Signed-off-by: Thomas Gleixner Cc: marc.zyngier@arm.com Link: https://lkml.kernel.org/r/1553439424-6529-1-git-send-email-psodagud@codeaurora.org --- diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c index 1401afa0d58a..53a081392115 100644 --- a/kernel/irq/manage.c +++ b/kernel/irq/manage.c @@ -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; }