ice: Fix improper handling of refcount in ice_dpll_init_rclk_pins()

This patch addresses a reference count handling issue in the
ice_dpll_init_rclk_pins() function. The function calls ice_dpll_get_pins(),
which increments the reference count of the relevant resources. However,
if the condition WARN_ON((!vsi || !vsi->netdev)) is met, the function
currently returns an error without properly releasing the resources
acquired by ice_dpll_get_pins(), leading to a reference count leak.

To resolve this, the check has been moved to the top of the function. This
ensures that the function verifies the state before any resources are
acquired, avoiding the need for additional resource management in the
error path.

This bug was identified by an experimental static analysis tool developed
by our team. The tool specializes in analyzing reference count operations
and detecting potential issues where resources are not properly managed.
In this case, the tool flagged the missing release operation as a
potential problem, which led to the development of this patch.

Fixes: d7999f5ea64b ("ice: implement dpll interface to control cgu")
Cc: stable@vger.kernel.org
Signed-off-by: Gui-Dong Han <hanguidong02@outlook.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Tested-by: Pucha Himasekhar Reddy <himasekharx.reddy.pucha@intel.com> (A Contingent worker at Intel)
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

diff --git a/drivers/net/ethernet/intel/ice/ice_dpll.c b/drivers/net/ethernet/intel/ice/ice_dpll.c
index cd95705d1e7fd6594bb71d8182a1c7b544ce71b5..8b6dc4d54fdc72fb9e3a77107f1612f620b4f12c 100644 (file)
--- a/drivers/net/ethernet/intel/ice/ice_dpll.c
+++ b/drivers/net/ethernet/intel/ice/ice_dpll.c
@@ -1843,6 +1843,8 @@ ice_dpll_init_rclk_pins(struct ice_pf *pf, struct ice_dpll_pin *pin,
        struct dpll_pin *parent;
        int ret, i;
 
+       if (WARN_ON((!vsi || !vsi->netdev)))
+               return -EINVAL;
        ret = ice_dpll_get_pins(pf, pin, start_idx, ICE_DPLL_RCLK_NUM_PER_PF,
                                pf->dplls.clock_id);
        if (ret)
@@ -1858,8 +1860,6 @@ ice_dpll_init_rclk_pins(struct ice_pf *pf, struct ice_dpll_pin *pin,
                if (ret)
                        goto unregister_pins;
        }
-       if (WARN_ON((!vsi || !vsi->netdev)))
-               return -EINVAL;
        dpll_netdev_pin_set(vsi->netdev, pf->dplls.rclk.pin);
 
        return 0;