From: Prasad Sodagudi <psodagud@xxxxxxxxxxxxxx> commit 59c39840f5abf4a71e1810a8da71aaccd6c17d26 upstream. 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@xxxxxxxxxxxxxx> Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Cc: marc.zyngier@xxxxxxx Link: https://lkml.kernel.org/r/1553439424-6529-1-git-send-email-psodagud@xxxxxxxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- kernel/irq/manage.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) --- a/kernel/irq/manage.c +++ b/kernel/irq/manage.c @@ -357,8 +357,10 @@ irq_set_affinity_notifier(unsigned int i 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; }
