From b790c8ea5593d6dc3580adfad8e117eeb56af874 Mon Sep 17 00:00:00 2001 From: Geert Uytterhoeven Date: Mon, 8 Oct 2018 13:14:35 +0200 Subject: [PATCH] reset: Fix potential use-after-free in __of_reset_control_get() Calling of_node_put() decreases the reference count of a device tree object, and may free some data. However, the of_phandle_args structure embedding it is passed to reset_controller_dev.of_xlate() after that, so it may still be accessed. Move the call to of_node_put() down to fix this. Signed-off-by: Geert Uytterhoeven [p.zabel@pengutronix.de: moved of_node_put after mutex_unlock] Signed-off-by: Philipp Zabel --- drivers/reset/core.c | 15 ++++++++------- 1 file changed, 8 insertions(+), 7 deletions(-) diff --git a/drivers/reset/core.c b/drivers/reset/core.c index 225e34c56b94..d1887c0ed5d3 100644 --- a/drivers/reset/core.c +++ b/drivers/reset/core.c @@ -496,28 +496,29 @@ struct reset_control *__of_reset_control_get(struct device_node *node, break; } } - of_node_put(args.np); if (!rcdev) { - mutex_unlock(&reset_list_mutex); - return ERR_PTR(-EPROBE_DEFER); + rstc = ERR_PTR(-EPROBE_DEFER); + goto out; } if (WARN_ON(args.args_count != rcdev->of_reset_n_cells)) { - mutex_unlock(&reset_list_mutex); - return ERR_PTR(-EINVAL); + rstc = ERR_PTR(-EINVAL); + goto out; } rstc_id = rcdev->of_xlate(rcdev, &args); if (rstc_id < 0) { - mutex_unlock(&reset_list_mutex); - return ERR_PTR(rstc_id); + rstc = ERR_PTR(rstc_id); + goto out; } /* reset_list_mutex also protects the rcdev's reset_control list */ rstc = __reset_control_get_internal(rcdev, rstc_id, shared); +out: mutex_unlock(&reset_list_mutex); + of_node_put(args.np); return rstc; } -- 2.30.2