diff options
author | Edward Cree <ecree@solarflare.com> | 2020-03-13 20:33:07 +0000 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-04-02 17:20:34 +0200 |
commit | cc24d74e50d21050fa9e8dcee2ef6460dca0d798 (patch) | |
tree | c335ba20dfcec806ab0da46129831baf5a31ac09 /kernel | |
parent | e52d8aff25010f4744022fca72d104ae7f074e19 (diff) |
genirq: Fix reference leaks on irq affinity notifiers
commit df81dfcfd6991d547653d46c051bac195cd182c1 upstream.
The handling of notify->work did not properly maintain notify->kref in two
cases:
1) where the work was already scheduled, another irq_set_affinity_locked()
would get the ref and (no-op-ly) schedule the work. Thus when
irq_affinity_notify() ran, it would drop the original ref but not the
additional one.
2) when cancelling the (old) work in irq_set_affinity_notifier(), if there
was outstanding work a ref had been got for it but was never put.
Fix both by checking the return values of the work handling functions
(schedule_work() for (1) and cancel_work_sync() for (2)) and put the
extra ref if the return value indicates preexisting work.
Fixes: cd7eab44e994 ("genirq: Add IRQ affinity notifiers")
Fixes: 59c39840f5ab ("genirq: Prevent use-after-free and work list corruption")
Signed-off-by: Edward Cree <ecree@solarflare.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Ben Hutchings <ben@decadent.org.uk>
Link: https://lkml.kernel.org/r/24f5983f-2ab5-e83a-44ee-a45b5f9300f5@solarflare.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'kernel')
-rw-r--r-- | kernel/irq/manage.c | 11 |
1 files changed, 9 insertions, 2 deletions
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c index be7f489788e2..b2fc2a581b86 100644 --- a/kernel/irq/manage.c +++ b/kernel/irq/manage.c @@ -233,7 +233,11 @@ int irq_set_affinity_locked(struct irq_data *data, const struct cpumask *mask, if (desc->affinity_notify) { kref_get(&desc->affinity_notify->kref); - schedule_work(&desc->affinity_notify->work); + if (!schedule_work(&desc->affinity_notify->work)) { + /* Work was already scheduled, drop our extra ref */ + kref_put(&desc->affinity_notify->kref, + desc->affinity_notify->release); + } } irqd_set(data, IRQD_AFFINITY_SET); @@ -333,7 +337,10 @@ irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify) raw_spin_unlock_irqrestore(&desc->lock, flags); if (old_notify) { - cancel_work_sync(&old_notify->work); + if (cancel_work_sync(&old_notify->work)) { + /* Pending work had a ref, put that one too */ + kref_put(&old_notify->kref, old_notify->release); + } kref_put(&old_notify->kref, old_notify->release); } |