[PATCH] virt/kvm/assigned-dev.c: Set 'dev->irq_source_id' to '-1' after free it

From: Chen Gang
Date: Fri Aug 08 2014 - 11:38:10 EST


As a generic function, deassign_guest_irq() assumes it can be called
even if assign_guest_irq() is not be called successfully (which can be
triggered by ioctl from user mode, indirectly).

So for assign_guest_irq() failure process, need set 'dev->irq_source_id'
to -1 after free 'dev->irq_source_id', or deassign_guest_irq() may free
it again.

Signed-off-by: Chen Gang <gang.chen.5i5j@xxxxxxxxx>
---
virt/kvm/assigned-dev.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/virt/kvm/assigned-dev.c b/virt/kvm/assigned-dev.c
index bf06577..5819a27 100644
--- a/virt/kvm/assigned-dev.c
+++ b/virt/kvm/assigned-dev.c
@@ -526,8 +526,10 @@ static int assign_guest_irq(struct kvm *kvm,
dev->irq_requested_type |= guest_irq_type;
if (dev->ack_notifier.gsi != -1)
kvm_register_irq_ack_notifier(kvm, &dev->ack_notifier);
- } else
+ } else {
kvm_free_irq_source_id(kvm, dev->irq_source_id);
+ dev->irq_source_id = -1;
+ }

return r;
}
--
1.7.11.7
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