diff mbox series

[4.9,080/139] vfio/pci: Clear token on bypass registration failure

Message ID 20201027134905.927592778@linuxfoundation.org
State Superseded
Headers show
Series None | expand

Commit Message

Greg KH Oct. 27, 2020, 1:49 p.m. UTC 
From: Alex Williamson <alex.williamson@redhat.com>

[ Upstream commit 852b1beecb6ff9326f7ca4bc0fe69ae860ebdb9e ]

The eventfd context is used as our irqbypass token, therefore if an
eventfd is re-used, our token is the same.  The irqbypass code will
return an -EBUSY in this case, but we'll still attempt to unregister
the producer, where if that duplicate token still exists, results in
removing the wrong object.  Clear the token of failed producers so
that they harmlessly fall out when unregistered.

Fixes: 6d7425f109d2 ("vfio: Register/unregister irq_bypass_producer")
Reported-by: guomin chen <guomin_chen@sina.com>
Tested-by: guomin chen <guomin_chen@sina.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/vfio/pci/vfio_pci_intrs.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/drivers/vfio/pci/vfio_pci_intrs.c b/drivers/vfio/pci/vfio_pci_intrs.c
index bdfdd506bc588..c989f777bf771 100644
--- a/drivers/vfio/pci/vfio_pci_intrs.c
+++ b/drivers/vfio/pci/vfio_pci_intrs.c
@@ -355,11 +355,13 @@  static int vfio_msi_set_vector_signal(struct vfio_pci_device *vdev,
 	vdev->ctx[vector].producer.token = trigger;
 	vdev->ctx[vector].producer.irq = irq;
 	ret = irq_bypass_register_producer(&vdev->ctx[vector].producer);
-	if (unlikely(ret))
+	if (unlikely(ret)) {
 		dev_info(&pdev->dev,
 		"irq bypass producer (token %p) registration fails: %d\n",
 		vdev->ctx[vector].producer.token, ret);
 
+		vdev->ctx[vector].producer.token = NULL;
+	}
 	vdev->ctx[vector].trigger = trigger;
 
 	return 0;