From 33f2aa87c294cdc704fa7fc578ebbca7868d393c Mon Sep 17 00:00:00 2001 From: Prasad Sodagudi Date: Sun, 24 Mar 2019 07:57:04 -0700 Subject: [PATCH] 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 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 Signed-off-by: Sasha Levin --- kernel/irq/manage.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c index 5c0ba5c..cd4f9f3 100644 --- a/kernel/irq/manage.c +++ b/kernel/irq/manage.c @@ -356,8 +356,10 @@ 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; } -- 2.7.4