Re: [PATCH net v2 1/4] dpll: fix pin dump crash after module unbind

[Jiri Pirko <jiri@resnulli.us>]

Thu, Jan 04, 2024 at 12:11:29PM CET, arkadiusz.kubalewski@intel.com wrote:
>Disallow dump of unregistered parent pins, it is possible when parent
>pin and dpll device registerer kernel module instance unbinds, and
>other kernel module instances of the same dpll device have pins
>registered with the parent pin. The user can invoke a pin-dump but as
>the parent was unregistered, those shall not be accessed by the
>userspace, prevent that by checking if parent pin is still registered.
>
>Fixes: 9d71b54b65b1 ("dpll: netlink: Add DPLL framework base functions")
>Reviewed-by: Jan Glaza <jan.glaza@intel.com>
>Signed-off-by: Arkadiusz Kubalewski <arkadiusz.kubalewski@intel.com>
>---
> drivers/dpll/dpll_netlink.c | 2 ++
> 1 file changed, 2 insertions(+)
>
>diff --git a/drivers/dpll/dpll_netlink.c b/drivers/dpll/dpll_netlink.c
>index ce7cf736f020..b53478374a38 100644
>--- a/drivers/dpll/dpll_netlink.c
>+++ b/drivers/dpll/dpll_netlink.c
>@@ -328,6 +328,8 @@ dpll_msg_add_pin_parents(struct sk_buff *msg, struct dpll_pin *pin,
> 		void *parent_priv;
> 
> 		ppin = ref->pin;
>+		if (!xa_get_mark(&dpll_pin_xa, ppin->id, DPLL_REGISTERED))
>+			continue;

If you make sure to hide the pin properly with the last patch, you don't
need this one. Drop it.


> 		parent_priv = dpll_pin_on_dpll_priv(dpll_ref->dpll, ppin);
> 		ret = ops->state_on_pin_get(pin,
> 					    dpll_pin_on_pin_priv(ppin, pin),
>-- 
>2.38.1
>