reset: Fix potential use-after-free in __of_reset_control_get() (b790c8ea) · Commits · 戴 / test

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 <geert+renesas@glider.be> [p.zabel@pengutronix.de: moved of_node_put after mutex_unlock] Signed-off-by:

Philipp Zabel <p.zabel@pengutronix.de>

drivers/reset/core.c

+8 −7

Original line number	Diff line number	Diff line
		@@ -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;
		}

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