On Tue, Feb 28, 2023 at 9:40 AM Jean-Jacques Hiblot
<jjhiblot@xxxxxxxxxxxxxxx> wrote:
>
> From: Jean Jacques Hiblot <jjhiblot@xxxxxxxxxxxxxxx>
>
> As all the other parsers do, parse_interrupt() must increase the refcount
> of the device_node. Otherwise the refcount is decremented every time
> parse_interrupt() is called on this node, leading to a potential
> use-after-free.
>
> This is a regression introduced by commit f265f06af194 ("of: property:
> Fix fw_devlink handling of interrupts/interrupts-extended"). The reason is
> that of_irq_parse_one() does not increase the refcount while the previously
> used of_irq_find_parent() does.
Thanks for catching the issue Jean!
This feels like a bug in of_irq_parse_one() to me. It's returning a
reference to a node without doing a of_node_get() on it.
Rob, Marc, Do you agree?
Jean,
If they agree, can you please fix of_irq_parse_one() and add a
of_node_put() to existing callers (if they aren't already doing a
put()).
Thanks,
Saravana
>
> Fixes: f265f06af194 ("of: property: Fix fw_devlink handling of interrupts/interrupts-extended")
> Signed-off-by: Jean Jacques Hiblot <jjhiblot@xxxxxxxxxxxxxxx>
> ---
> drivers/of/property.c | 5 ++++-
> 1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/of/property.c b/drivers/of/property.c
> index 134cfc980b70b..1f23bcb765c4e 100644
> --- a/drivers/of/property.c
> +++ b/drivers/of/property.c
> @@ -1380,7 +1380,10 @@ static struct device_node *parse_interrupts(struct device_node *np,
> strcmp(prop_name, "interrupts-extended"))
> return NULL;
>
> - return of_irq_parse_one(np, index, &sup_args) ? NULL : sup_args.np;
> + if (of_irq_parse_one(np, index, &sup_args))
> + return NULL;
> +
> + return of_node_get(sup_args.np);
> }
>
> static const struct supplier_bindings of_supplier_bindings[] = {
> --
> 2.25.1
>
