From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 22C9BB67E; Wed, 8 Apr 2026 18:37:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775673457; cv=none; b=OpdltPiJzplV9G9wmO5jn6Y4TsFAC6EwUaM+WP07l7q6W61Z2NhaM7hb3Y3XrHPLjaWNpKBs73U0H2wljQD7NL4cPRyKehbCpkGMhQm75T6aJXwY5VodvozzFyX/4yQoxK5subViunf/dt9hTNOYHQ3HBtpTayBrLpZh7oAebdA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775673457; c=relaxed/simple; bh=j0d/xoyke+T3cf3brdl+FxERuAiLs1eqBW9DFAhjgLw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=VcXxH9HfV5NYE1a9iCPFFyjWJg83pntX48gepxRzFxIsMUVEIhO3XFBihSDmBiGc1m5W0copBlqy0PvBAgRSI25O9lpP+KIZy4c2I69qifPOpED2s1r2GV9HA340ydFvnlD6pFkETxQVi9p2ZakFtKtyHPYXCGpy9drr7JvLfhA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=KR/sYh06; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="KR/sYh06" Received: by smtp.kernel.org (Postfix) with ESMTPSA id AEEB7C19421; Wed, 8 Apr 2026 18:37:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1775673457; bh=j0d/xoyke+T3cf3brdl+FxERuAiLs1eqBW9DFAhjgLw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=KR/sYh06GVSwaiF/vRMmIBfhlcJHuN9u2IxI5cimSob0ji6v8IKxHsaWkPO+n2v80 vfq0kFzItbiT/LBLt8mOJ+qCDEMZ9nGevETPjXrzPkTMotsGusLi0ylWXGV8uOALxF 333ySUYo1TlmOSVMlxJtdaQsTNgE4WWrYSy4A73E= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Linus Walleij , Tzung-Bi Shih , Bartosz Golaszewski Subject: [PATCH 6.18 239/277] gpio: Fix resource leaks on errors in gpiochip_add_data_with_key() Date: Wed, 8 Apr 2026 20:03:44 +0200 Message-ID: <20260408175942.784055392@linuxfoundation.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260408175933.836769063@linuxfoundation.org> References: <20260408175933.836769063@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Tzung-Bi Shih commit 16fdabe143fce2cbf89139677728e17e21b46c28 upstream. Since commit aab5c6f20023 ("gpio: set device type for GPIO chips"), `gdev->dev.release` is unset. As a result, the reference count to `gdev->dev` isn't dropped on the error handling paths. Drop the reference on errors. Also reorder the instructions to make the error handling simpler. Now gpiochip_add_data_with_key() roughly looks like: >>> Some memory allocation. Go to ERR ZONE 1 on errors. >>> device_initialize(). gpiodev_release() takes over the responsibility for freeing the resources of `gdev->dev`. The subsequent error handling paths shouldn't go through ERR ZONE 1 again which leads to double free. >>> Some initialization mainly on `gdev`. >>> The rest of initialization. Go to ERR ZONE 2 on errors. >>> Chip registration success and exit. >>> ERR ZONE 2. gpio_device_put() and exit. >>> ERR ZONE 1. Cc: stable@vger.kernel.org Fixes: aab5c6f20023 ("gpio: set device type for GPIO chips") Reviewed-by: Linus Walleij Signed-off-by: Tzung-Bi Shih Link: https://patch.msgid.link/20260205092840.2574840-1-tzungbi@kernel.org Signed-off-by: Bartosz Golaszewski Signed-off-by: Greg Kroah-Hartman --- drivers/gpio/gpiolib.c | 101 +++++++++++++++++++++++-------------------------- 1 file changed, 48 insertions(+), 53 deletions(-) --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -882,13 +882,15 @@ static const struct device_type gpio_dev #define gcdev_unregister(gdev) device_del(&(gdev)->dev) #endif +/* + * An initial reference count has been held in gpiochip_add_data_with_key(). + * The caller should drop the reference via gpio_device_put() on errors. + */ static int gpiochip_setup_dev(struct gpio_device *gdev) { struct fwnode_handle *fwnode = dev_fwnode(&gdev->dev); int ret; - device_initialize(&gdev->dev); - /* * If fwnode doesn't belong to another device, it's safe to clear its * initialized flag. @@ -954,9 +956,11 @@ static void gpiochip_setup_devs(void) list_for_each_entry_srcu(gdev, &gpio_devices, list, srcu_read_lock_held(&gpio_devices_srcu)) { ret = gpiochip_setup_dev(gdev); - if (ret) + if (ret) { + gpio_device_put(gdev); dev_err(&gdev->dev, "Failed to initialize gpio device (%d)\n", ret); + } } } @@ -1037,71 +1041,72 @@ int gpiochip_add_data_with_key(struct gp int base = 0; int ret; - /* - * First: allocate and populate the internal stat container, and - * set up the struct device. - */ gdev = kzalloc(sizeof(*gdev), GFP_KERNEL); if (!gdev) return -ENOMEM; - - gdev->dev.type = &gpio_dev_type; - gdev->dev.bus = &gpio_bus_type; - gdev->dev.parent = gc->parent; - rcu_assign_pointer(gdev->chip, gc); - gc->gpiodev = gdev; gpiochip_set_data(gc, data); - device_set_node(&gdev->dev, gpiochip_choose_fwnode(gc)); - ret = ida_alloc(&gpio_ida, GFP_KERNEL); if (ret < 0) goto err_free_gdev; gdev->id = ret; - ret = dev_set_name(&gdev->dev, GPIOCHIP_NAME "%d", gdev->id); + ret = init_srcu_struct(&gdev->srcu); if (ret) goto err_free_ida; + rcu_assign_pointer(gdev->chip, gc); - if (gc->parent && gc->parent->driver) - gdev->owner = gc->parent->driver->owner; - else if (gc->owner) - /* TODO: remove chip->owner */ - gdev->owner = gc->owner; - else - gdev->owner = THIS_MODULE; + ret = init_srcu_struct(&gdev->desc_srcu); + if (ret) + goto err_cleanup_gdev_srcu; + + ret = dev_set_name(&gdev->dev, GPIOCHIP_NAME "%d", gdev->id); + if (ret) + goto err_cleanup_desc_srcu; + + device_initialize(&gdev->dev); + /* + * After this point any allocated resources to `gdev` will be + * free():ed by gpiodev_release(). If you add new resources + * then make sure they get free():ed there. + */ + gdev->dev.type = &gpio_dev_type; + gdev->dev.bus = &gpio_bus_type; + gdev->dev.parent = gc->parent; + device_set_node(&gdev->dev, gpiochip_choose_fwnode(gc)); ret = gpiochip_get_ngpios(gc, &gdev->dev); if (ret) - goto err_free_dev_name; + goto err_put_device; + gdev->ngpio = gc->ngpio; gdev->descs = kcalloc(gc->ngpio, sizeof(*gdev->descs), GFP_KERNEL); if (!gdev->descs) { ret = -ENOMEM; - goto err_free_dev_name; + goto err_put_device; } gdev->label = kstrdup_const(gc->label ?: "unknown", GFP_KERNEL); if (!gdev->label) { ret = -ENOMEM; - goto err_free_descs; + goto err_put_device; } - gdev->ngpio = gc->ngpio; gdev->can_sleep = gc->can_sleep; - rwlock_init(&gdev->line_state_lock); RAW_INIT_NOTIFIER_HEAD(&gdev->line_state_notifier); BLOCKING_INIT_NOTIFIER_HEAD(&gdev->device_notifier); - - ret = init_srcu_struct(&gdev->srcu); - if (ret) - goto err_free_label; - - ret = init_srcu_struct(&gdev->desc_srcu); - if (ret) - goto err_cleanup_gdev_srcu; +#ifdef CONFIG_PINCTRL + INIT_LIST_HEAD(&gdev->pin_ranges); +#endif + if (gc->parent && gc->parent->driver) + gdev->owner = gc->parent->driver->owner; + else if (gc->owner) + /* TODO: remove chip->owner */ + gdev->owner = gc->owner; + else + gdev->owner = THIS_MODULE; scoped_guard(mutex, &gpio_devices_lock) { /* @@ -1117,7 +1122,7 @@ int gpiochip_add_data_with_key(struct gp if (base < 0) { ret = base; base = 0; - goto err_cleanup_desc_srcu; + goto err_put_device; } /* @@ -1137,14 +1142,10 @@ int gpiochip_add_data_with_key(struct gp ret = gpiodev_add_to_list_unlocked(gdev); if (ret) { gpiochip_err(gc, "GPIO integer space overlap, cannot add chip\n"); - goto err_cleanup_desc_srcu; + goto err_put_device; } } -#ifdef CONFIG_PINCTRL - INIT_LIST_HEAD(&gdev->pin_ranges); -#endif - if (gc->names) gpiochip_set_desc_names(gc); @@ -1231,25 +1232,19 @@ err_remove_from_list: scoped_guard(mutex, &gpio_devices_lock) list_del_rcu(&gdev->list); synchronize_srcu(&gpio_devices_srcu); - if (gdev->dev.release) { - /* release() has been registered by gpiochip_setup_dev() */ - gpio_device_put(gdev); - goto err_print_message; - } +err_put_device: + gpio_device_put(gdev); + goto err_print_message; + err_cleanup_desc_srcu: cleanup_srcu_struct(&gdev->desc_srcu); err_cleanup_gdev_srcu: cleanup_srcu_struct(&gdev->srcu); -err_free_label: - kfree_const(gdev->label); -err_free_descs: - kfree(gdev->descs); -err_free_dev_name: - kfree(dev_name(&gdev->dev)); err_free_ida: ida_free(&gpio_ida, gdev->id); err_free_gdev: kfree(gdev); + err_print_message: /* failures here can mean systems won't boot... */ if (ret != -EPROBE_DEFER) {