From f7aa9de4f2b197cdd704cdc476901b68ee128433 Mon Sep 17 00:00:00 2001 From: AngeloGioacchino Del Regno Date: Tue, 21 Jul 2026 11:36:15 +0200 Subject: [PATCH] spmi: Fix potential use-after-free by grabbing of_node reference As noticed by Sashiko during a review run of an unrelated patch, in of_spmi_register_devices(), for_each_available_child_of_node() is used to loop through children, and to also assign a node to a newly created SPMI child device. Problem is that the refcount is dropped at every iteration so, in the specific case of DT overlays, a use-after-free may occur when an overlay is dynamically unloaded! To resolve this, increase the of_node refcount when assigning (in function of_spmi_register_devices) and release the reference in spmi_device_remove(). Fixes: bc32bbd04011 ("spmi: Set fwnode for spmi devices") Cc: stable@vger.kernel.org Reported-by: Sashiko Bot Closes: https://sashiko.dev/#/patchset/20260608100949.36309-1-angelogioacchino.delregno@collabora.com?part=2 Signed-off-by: AngeloGioacchino Del Regno Signed-off-by: Stephen Boyd --- drivers/spmi/spmi.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/spmi/spmi.c b/drivers/spmi/spmi.c index 57b7c0cb4240..f6d2f4bddfcd 100644 --- a/drivers/spmi/spmi.c +++ b/drivers/spmi/spmi.c @@ -24,6 +24,7 @@ static void spmi_dev_release(struct device *dev) { struct spmi_device *sdev = to_spmi_device(dev); + of_node_put(dev->of_node); kfree(sdev); } @@ -517,7 +518,7 @@ static void of_spmi_register_devices(struct spmi_controller *ctrl) if (!sdev) continue; - device_set_node(&sdev->dev, of_fwnode_handle(node)); + device_set_node(&sdev->dev, of_fwnode_handle(of_node_get(node))); sdev->usid = (u8)reg[0]; err = spmi_device_add(sdev);