[PATCH 4.9 115/175] irqchip/alpine-msi: Fix freeing of interrupts on allocation error path

[Greg Kroah-Hartman]

From: Marc Zyngier <maz@xxxxxxxxxx>

[ Upstream commit 3841245e8498a789c65dedd7ffa8fb2fee2c0684 ]

The alpine-msi driver has an interesting allocation error handling,
where it frees the same interrupts repeatedly. Hilarity follows.

This code is probably never executed, but let's fix it nonetheless.

Fixes: e6b78f2c3e14 ("irqchip: Add the Alpine MSIX interrupt controller")
Signed-off-by: Marc Zyngier <maz@xxxxxxxxxx>
Reviewed-by: Antoine Tenart <atenart@xxxxxxxxxx>
Cc: Tsahee Zidenberg <tsahee@xxxxxxxxxxxxxxxxx>
Cc: Antoine Tenart <atenart@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20201129135525.396671-1-maz@xxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/irqchip/irq-alpine-msi.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/irqchip/irq-alpine-msi.c b/drivers/irqchip/irq-alpine-msi.c
index 63d980995d17d..ac431697ebe1c 100644
--- a/drivers/irqchip/irq-alpine-msi.c
+++ b/drivers/irqchip/irq-alpine-msi.c
@@ -165,8 +165,7 @@ static int alpine_msix_middle_domain_alloc(struct irq_domain *domain,
 	return 0;
 
 err_sgi:
-	while (--i >= 0)
-		irq_domain_free_irqs_parent(domain, virq, i);
+	irq_domain_free_irqs_parent(domain, virq, i - 1);
 	alpine_msix_free_sgi(priv, sgi, nr_irqs);
 	return err;
 }
-- 
2.27.0