[PATCH v1] irqchip/gic-v3-its: Drop ITS node reference on its_of_probe() errors

[PATCH v1] irqchip/gic-v3-its: Drop ITS node reference on its_of_probe() errors

[Yuho Choi]

its_of_probe() walks the ITS nodes with of_find_matching_node(), which
drops the reference on the previous node and returns the next one with
its reference count raised.  The loops are balanced when they run to the
end, but the three error returns (a failed its_reset_one(), a failed
its_node_init() and a failed its_probe_one()) leave with the current
node still referenced.

Drop it before returning.

Fixes: c733ebb7cb67 ("irqchip/gic-v3-its: Reset each ITS's BASERn register before probe")
Fixes: 9585a495ac93 ("irqchip/gic-v3-its: Split allocation from initialisation of its_node")
Signed-off-by: Yuho Choi <oss.patchbox@gmail.com>
---
Compile-tested only (arm64 defconfig, W=1).

 drivers/irqchip/irq-gic-v3-its.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index e9807af23537..6361d20bd920 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -5579,8 +5579,10 @@ static int __init its_of_probe(struct device_node *node)
 			continue;
 
 		err = its_reset_one(&res);
-		if (err)
+		if (err) {
+			of_node_put(np);
 			return err;
+		}
 	}
 
 	for (np = of_find_matching_node(node, its_device_id); np;
@@ -5602,12 +5604,15 @@ static int __init its_of_probe(struct device_node *node)
 
 
 		its = its_node_init(&res, &np->fwnode, of_node_to_nid(np));
-		if (!its)
+		if (!its) {
+			of_node_put(np);
 			return -ENOMEM;
+		}
 
 		err = its_probe_one(its);
 		if (err)  {
 			its_node_destroy(its);
+			of_node_put(np);
 			return err;
 		}
 	}

base-commit: f0100363d8c374bd8e9ea7c9ba02744f0b802ca4
-- 
2.43.0

Re: [PATCH v1] irqchip/gic-v3-its: Drop ITS node reference on its_of_probe() errors

[Jonathan Cameron]

On Wed, 23 Sep 2026 12:54:40 -0400
Yuho Choi <oss.patchbox@gmail.com> wrote:

> its_of_probe() walks the ITS nodes with of_find_matching_node(), which
> drops the reference on the previous node and returns the next one with
> its reference count raised.  The loops are balanced when they run to the
> end, but the three error returns (a failed its_reset_one(), a failed
> its_node_init() and a failed its_probe_one()) leave with the current
> node still referenced.
> 
> Drop it before returning.
> 
> Fixes: c733ebb7cb67 ("irqchip/gic-v3-its: Reset each ITS's BASERn register before probe")
> Fixes: 9585a495ac93 ("irqchip/gic-v3-its: Split allocation from initialisation of its_node")
> Signed-off-by: Yuho Choi <oss.patchbox@gmail.com>

I only took a very quick look but why can't this use for_each_matching_node()

That doesn't solve your problem but it would be easy to add a for_each_matching_node_scoped()
in similar spirit to for_each_child_of_node_scoped() I think and that would give you a cleaner fix here.

There may well be other places such a macro would benefit. I just haven't looked!

Jonathan


> ---
> Compile-tested only (arm64 defconfig, W=1).
> 
>  drivers/irqchip/irq-gic-v3-its.c | 9 +++++++--
>  1 file changed, 7 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
> index e9807af23537..6361d20bd920 100644
> --- a/drivers/irqchip/irq-gic-v3-its.c
> +++ b/drivers/irqchip/irq-gic-v3-its.c
> @@ -5579,8 +5579,10 @@ static int __init its_of_probe(struct device_node *node)
>  			continue;
>  
>  		err = its_reset_one(&res);
> -		if (err)
> +		if (err) {
> +			of_node_put(np);
>  			return err;
> +		}
>  	}
>  
>  	for (np = of_find_matching_node(node, its_device_id); np;
> @@ -5602,12 +5604,15 @@ static int __init its_of_probe(struct device_node *node)
>  
>  
>  		its = its_node_init(&res, &np->fwnode, of_node_to_nid(np));
> -		if (!its)
> +		if (!its) {
> +			of_node_put(np);
>  			return -ENOMEM;
> +		}
>  
>  		err = its_probe_one(its);
>  		if (err)  {
>  			its_node_destroy(its);
> +			of_node_put(np);
>  			return err;
>  		}
>  	}
> 
> base-commit: f0100363d8c374bd8e9ea7c9ba02744f0b802ca4