This is a note to let you know that I've just added the patch titled
vfio/pci: Clear token on bypass registration failure
to the 5.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
vfio-pci-clear-token-on-bypass-registration-failure.patch
and it can be found in the queue-5.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 4831f82126167196d64e51acdf28fb24888f746b
Author: Alex Williamson <alex.williamson@xxxxxxxxxx>
Date: Mon Oct 19 07:13:55 2020 -0600
vfio/pci: Clear token on bypass registration failure
[ 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@xxxxxxxx>
Tested-by: guomin chen <guomin_chen@xxxxxxxx>
Signed-off-by: Alex Williamson <alex.williamson@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/vfio/pci/vfio_pci_intrs.c b/drivers/vfio/pci/vfio_pci_intrs.c
index 1d9fb25929459..869dce5f134dd 100644
--- a/drivers/vfio/pci/vfio_pci_intrs.c
+++ b/drivers/vfio/pci/vfio_pci_intrs.c
@@ -352,11 +352,13 @@ 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;
