[PATCH v3 4/5] nvmem: core: fix cleanup after dev_set_name() Bartosz Golaszewski <bgolaszewski@xxxxxxxxxxxx>,Gaosheng Cui <cuigaosheng1@xxxxxxxxxx>,Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>,linux-arm-kernel@xxxxxxxxxxxxxxxxxxx,linux-kernel@xxxxxxxxxxxxxxx,Maxime Ripard <mripard@xxxxxxxxxx>, Hector Martin <marcan@xxxxxxxxx>

From: Russell King (Oracle)
Date: Tue Jan 03 2023 - 11:59:48 EST


If dev_set_name() fails, we leak nvmem->wp_gpio as the cleanup does not
put this. While a minimal fix for this would be to add the gpiod_put()
call, we can do better if we split device_register(), and use the
tested nvmem_release() cleanup code by initialising the device early,
and putting the device.

This results in a slightly larger fix, but results in clear code.

Note: this patch depends on "nvmem: core: initialise nvmem->id early"
and "nvmem: core: remove nvmem_config wp_gpio".

Fixes: 5544e90c8126 ("nvmem: core: add error handling for dev_set_name")
Signed-off-by: Russell King (Oracle) <rmk+kernel@xxxxxxxxxxxxxxx>
---
drivers/nvmem/core.c | 26 +++++++++++---------------
1 file changed, 11 insertions(+), 15 deletions(-)

diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c
index 843e2f5696e6..19497f555e07 100644
--- a/drivers/nvmem/core.c
+++ b/drivers/nvmem/core.c
@@ -772,15 +772,17 @@ struct nvmem_device *nvmem_register(const struct nvmem_config *config)

nvmem->id = rval;

+ nvmem->dev.type = &nvmem_provider_type;
+ nvmem->dev.bus = &nvmem_bus_type;
+ nvmem->dev.parent = config->dev;
+
+ device_initialize(&nvmem->dev);
+
if (!config->ignore_wp)
nvmem->wp_gpio = gpiod_get_optional(config->dev, "wp",
GPIOD_OUT_HIGH);
- if (IS_ERR(nvmem->wp_gpio)) {
- ida_free(&nvmem_ida, nvmem->id);
- rval = PTR_ERR(nvmem->wp_gpio);
- kfree(nvmem);
- return ERR_PTR(rval);
- }
+ if (IS_ERR(nvmem->wp_gpio))
+ goto err_put_device;

kref_init(&nvmem->refcnt);
INIT_LIST_HEAD(&nvmem->cells);
@@ -791,9 +793,6 @@ struct nvmem_device *nvmem_register(const struct nvmem_config *config)
nvmem->stride = config->stride ?: 1;
nvmem->word_size = config->word_size ?: 1;
nvmem->size = config->size;
- nvmem->dev.type = &nvmem_provider_type;
- nvmem->dev.bus = &nvmem_bus_type;
- nvmem->dev.parent = config->dev;
nvmem->root_only = config->root_only;
nvmem->priv = config->priv;
nvmem->type = config->type;
@@ -821,11 +820,8 @@ struct nvmem_device *nvmem_register(const struct nvmem_config *config)
break;
}

- if (rval) {
- ida_free(&nvmem_ida, nvmem->id);
- kfree(nvmem);
- return ERR_PTR(rval);
- }
+ if (rval)
+ goto err_put_device;

nvmem->read_only = device_property_present(config->dev, "read-only") ||
config->read_only || !nvmem->reg_write;
@@ -836,7 +832,7 @@ struct nvmem_device *nvmem_register(const struct nvmem_config *config)

dev_dbg(&nvmem->dev, "Registering nvmem device %s\n", config->name);

- rval = device_register(&nvmem->dev);
+ rval = device_add(&nvmem->dev);
if (rval)
goto err_put_device;

--
2.30.2