2020-09-02 18:47:00

by Alex Dewar

[permalink] [raw]
Subject: [PATCH] staging: media: atomisp: Fix error path in lm3554_probe()

The error path for lm3554_probe() contains a number of bugs, including:
* resource leaks
* jumping to error labels out of sequence
* not setting the return value appropriately

Fix it up and give the labels more memorable names.

This issue has existed since the code was originally contributed in
commit a49d25364dfb ("staging/atomisp: Add support for the Intel IPU v2"),
although the code was subsequently removed altogether and then
reinstated with commit ad85094b293e ("Revert "media: staging: atomisp: Remove driver"").

Addresses-Coverity: ("Resource leak")
Fixes: a49d25364dfb ("staging/atomisp: Add support for the Intel IPU v2")
Signed-off-by: Alex Dewar <[email protected]>
---
.../media/atomisp/i2c/atomisp-lm3554.c | 47 ++++++++++---------
1 file changed, 25 insertions(+), 22 deletions(-)

diff --git a/drivers/staging/media/atomisp/i2c/atomisp-lm3554.c b/drivers/staging/media/atomisp/i2c/atomisp-lm3554.c
index 7ca7378b1859..9aad6721fc84 100644
--- a/drivers/staging/media/atomisp/i2c/atomisp-lm3554.c
+++ b/drivers/staging/media/atomisp/i2c/atomisp-lm3554.c
@@ -833,7 +833,6 @@ static void *lm3554_platform_data_func(struct i2c_client *client)

static int lm3554_probe(struct i2c_client *client)
{
- int err = 0;
struct lm3554 *flash;
unsigned int i;
int ret;
@@ -843,36 +842,38 @@ static int lm3554_probe(struct i2c_client *client)
return -ENOMEM;

flash->pdata = lm3554_platform_data_func(client);
- if (IS_ERR(flash->pdata))
- return PTR_ERR(flash->pdata);
+ if (IS_ERR(flash->pdata)) {
+ ret = PTR_ERR(flash->pdata);
+ goto err_free_flash;
+ }

v4l2_i2c_subdev_init(&flash->sd, client, &lm3554_ops);
flash->sd.internal_ops = &lm3554_internal_ops;
flash->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
flash->mode = ATOMISP_FLASH_MODE_OFF;
flash->timeout = LM3554_MAX_TIMEOUT / LM3554_TIMEOUT_STEPSIZE - 1;
- ret =
- v4l2_ctrl_handler_init(&flash->ctrl_handler,
- ARRAY_SIZE(lm3554_controls));
+ ret = v4l2_ctrl_handler_init(&flash->ctrl_handler,
+ ARRAY_SIZE(lm3554_controls));
if (ret) {
- dev_err(&client->dev, "error initialize a ctrl_handler.\n");
- goto fail2;
+ dev_err(&client->dev, "error initializing ctrl_handler");
+ goto err_unregister_sd;
}

for (i = 0; i < ARRAY_SIZE(lm3554_controls); i++)
v4l2_ctrl_new_custom(&flash->ctrl_handler, &lm3554_controls[i],
NULL);

- if (flash->ctrl_handler.error) {
- dev_err(&client->dev, "ctrl_handler error.\n");
- goto fail2;
+ ret = flash->ctrl_handler.error;
+ if (ret) {
+ dev_err(&client->dev, "ctrl_handler error");
+ goto err_free_ctrl_handler;
}

flash->sd.ctrl_handler = &flash->ctrl_handler;
- err = media_entity_pads_init(&flash->sd.entity, 0, NULL);
- if (err) {
- dev_err(&client->dev, "error initialize a media entity.\n");
- goto fail1;
+ ret = media_entity_pads_init(&flash->sd.entity, 0, NULL);
+ if (ret) {
+ dev_err(&client->dev, "error initializing media entity");
+ goto err_free_ctrl_handler;
}

flash->sd.entity.function = MEDIA_ENT_F_FLASH;
@@ -881,20 +882,22 @@ static int lm3554_probe(struct i2c_client *client)

timer_setup(&flash->flash_off_delay, lm3554_flash_off_delay, 0);

- err = lm3554_gpio_init(client);
- if (err) {
+ ret = lm3554_gpio_init(client);
+ if (ret) {
dev_err(&client->dev, "gpio request/direction_output fail");
- goto fail2;
+ goto err_cleanup_entity;
}
return atomisp_register_i2c_module(&flash->sd, NULL, LED_FLASH);
-fail2:
+
+err_cleanup_entity:
media_entity_cleanup(&flash->sd.entity);
+err_free_ctrl_handler:
v4l2_ctrl_handler_free(&flash->ctrl_handler);
-fail1:
+err_unregister_sd:
v4l2_device_unregister_subdev(&flash->sd);
+err_free_flash:
kfree(flash);
-
- return err;
+ return ret;
}

static int lm3554_remove(struct i2c_client *client)
--
2.28.0


2020-09-03 12:24:04

by Dan Carpenter

[permalink] [raw]
Subject: Re: [PATCH] staging: media: atomisp: Fix error path in lm3554_probe()

On Wed, Sep 02, 2020 at 07:41:50PM +0100, Alex Dewar wrote:
> The error path for lm3554_probe() contains a number of bugs, including:
> * resource leaks
> * jumping to error labels out of sequence
> * not setting the return value appropriately
>
> Fix it up and give the labels more memorable names.
>
> This issue has existed since the code was originally contributed in
> commit a49d25364dfb ("staging/atomisp: Add support for the Intel IPU v2"),
> although the code was subsequently removed altogether and then
> reinstated with commit ad85094b293e ("Revert "media: staging: atomisp: Remove driver"").
>

Almost perfect! Just a couple other leaks we should fix as well.

> + ret = media_entity_pads_init(&flash->sd.entity, 0, NULL);
> + if (ret) {
> + dev_err(&client->dev, "error initializing media entity");
> + goto err_free_ctrl_handler;
> }
>
> flash->sd.entity.function = MEDIA_ENT_F_FLASH;
> @@ -881,20 +882,22 @@ static int lm3554_probe(struct i2c_client *client)
>
> timer_setup(&flash->flash_off_delay, lm3554_flash_off_delay, 0);

We need to delete this timer.

>
> - err = lm3554_gpio_init(client);
> - if (err) {
> + ret = lm3554_gpio_init(client);
> + if (ret) {
> dev_err(&client->dev, "gpio request/direction_output fail");
> - goto fail2;
> + goto err_cleanup_entity;
> }
> return atomisp_register_i2c_module(&flash->sd, NULL, LED_FLASH);

If atomisp_register_i2c_module() fails then we need to call
lm3554_gpio_uninit(client) and do other cleanup.

> -fail2:
> +
> +err_cleanup_entity:
> media_entity_cleanup(&flash->sd.entity);
> +err_free_ctrl_handler:
> v4l2_ctrl_handler_free(&flash->ctrl_handler);

regards,
dan carpenter

2020-09-03 15:52:27

by Alex Dewar

[permalink] [raw]
Subject: Re: [PATCH] staging: media: atomisp: Fix error path in lm3554_probe()

Good point about the timer!

> >
> > - err = lm3554_gpio_init(client);
> > - if (err) {
> > + ret = lm3554_gpio_init(client);
> > + if (ret) {
> > dev_err(&client->dev, "gpio request/direction_output fail");
> > - goto fail2;
> > + goto err_cleanup_entity;
> > }
> > return atomisp_register_i2c_module(&flash->sd, NULL, LED_FLASH);
>
> If atomisp_register_i2c_module() fails then we need to call
> lm3554_gpio_uninit(client) and do other cleanup.

I'm probably showing my ignorance here, but I can't see what cleanup we
need. Inside lm3554_gpio_init we have:

ret = gpiod_direction_output(pdata->gpio_reset, 0);
if (ret < 0)
return ret;
dev_info(&client->dev, "flash led reset successfully\n");

if (!pdata->gpio_strobe)
return -EINVAL;

ret = gpiod_direction_output(pdata->gpio_strobe, 0);
if (ret < 0)
return ret;

I'm not sure how you "undo" a call to gpiod_direction_output, but I'm
thinking you won't need to do anything because it should be ok to leave
a gpio to output 0... right?

Alex

>
> > -fail2:
> > +
> > +err_cleanup_entity:
> > media_entity_cleanup(&flash->sd.entity);
> > +err_free_ctrl_handler:
> > v4l2_ctrl_handler_free(&flash->ctrl_handler);
>
> regards,
> dan carpenter
>

2020-09-03 17:40:13

by Dan Carpenter

[permalink] [raw]
Subject: Re: [PATCH] staging: media: atomisp: Fix error path in lm3554_probe()

On Thu, Sep 03, 2020 at 04:48:41PM +0100, Alex Dewar wrote:
> Good point about the timer!
>
> > >
> > > - err = lm3554_gpio_init(client);
> > > - if (err) {
> > > + ret = lm3554_gpio_init(client);
> > > + if (ret) {
> > > dev_err(&client->dev, "gpio request/direction_output fail");
> > > - goto fail2;
> > > + goto err_cleanup_entity;
> > > }
> > > return atomisp_register_i2c_module(&flash->sd, NULL, LED_FLASH);
> >
> > If atomisp_register_i2c_module() fails then we need to call
> > lm3554_gpio_uninit(client) and do other cleanup.
>
> I'm probably showing my ignorance here, but I can't see what cleanup we
> need. Inside lm3554_gpio_init we have:
>
> ret = gpiod_direction_output(pdata->gpio_reset, 0);
> if (ret < 0)
> return ret;
> dev_info(&client->dev, "flash led reset successfully\n");
>
> if (!pdata->gpio_strobe)
> return -EINVAL;
>
> ret = gpiod_direction_output(pdata->gpio_strobe, 0);
> if (ret < 0)
> return ret;
>
> I'm not sure how you "undo" a call to gpiod_direction_output, but I'm
> thinking you won't need to do anything because it should be ok to leave
> a gpio to output 0... right?

You're right. I wonder if there is really any need for the
lm3554_gpio_uninit() function at all? It's basically the same as
lm3554_gpio_init() except for the order of function calls. Probably
we could just rename lm3554_gpio_init() to something like
lm3554_gpio_set_default() and use it in both the probe() and remove
functions()...

But I don't know the code and can't test it so let's leave that for
another day.

We still do need to clean up if atomisp_register_i2c_module() fails
though, and the timer as well so could you resend a v2?

regards,
dan carpenter

2020-09-03 18:24:49

by Alex Dewar

[permalink] [raw]
Subject: Re: [PATCH] staging: media: atomisp: Fix error path in lm3554_probe()

> You're right. I wonder if there is really any need for the
> lm3554_gpio_uninit() function at all? It's basically the same as
> lm3554_gpio_init() except for the order of function calls. Probably
> we could just rename lm3554_gpio_init() to something like
> lm3554_gpio_set_default() and use it in both the probe() and remove
> functions()...

I think you probably also don't want to return error values from
lm3554_gpio_uninit() as it is only called on module removal, so it'd
probably make more sense to just print a warning and carry on. I'll do
this as a separate patch and send it to the list, though.

v2 to follow...

>
> But I don't know the code and can't test it so let's leave that for
> another day.
>
> We still do need to clean up if atomisp_register_i2c_module() fails
> though, and the timer as well so could you resend a v2?
>
> regards,
> dan carpenter
>

2020-09-03 18:26:39

by Alex Dewar

[permalink] [raw]
Subject: [PATCH v2] staging: media: atomisp: Fix error path in lm3554_probe()

The error path for lm3554_probe() contains a number of bugs, including:
* resource leaks
* jumping to error labels out of sequence
* not setting the return value appropriately

Fix it up and give the labels more memorable names.

This issue has existed since the code was originally contributed in
commit a49d25364dfb ("staging/atomisp: Add support for the Intel IPU v2"),
although the code was subsequently removed altogether and then
reinstated with commit ad85094b293e ("Revert "media: staging: atomisp: Remove driver"").

Addresses-Coverity: 1496802 ("Resource leaks")
Fixes: a49d25364dfb ("staging/atomisp: Add support for the Intel IPU v2")
Signed-off-by: Alex Dewar <[email protected]>
---
.../media/atomisp/i2c/atomisp-lm3554.c | 53 +++++++++++--------
1 file changed, 30 insertions(+), 23 deletions(-)

diff --git a/drivers/staging/media/atomisp/i2c/atomisp-lm3554.c b/drivers/staging/media/atomisp/i2c/atomisp-lm3554.c
index 7ca7378b1859..cca10a4c2db0 100644
--- a/drivers/staging/media/atomisp/i2c/atomisp-lm3554.c
+++ b/drivers/staging/media/atomisp/i2c/atomisp-lm3554.c
@@ -833,7 +833,6 @@ static void *lm3554_platform_data_func(struct i2c_client *client)

static int lm3554_probe(struct i2c_client *client)
{
- int err = 0;
struct lm3554 *flash;
unsigned int i;
int ret;
@@ -843,36 +842,38 @@ static int lm3554_probe(struct i2c_client *client)
return -ENOMEM;

flash->pdata = lm3554_platform_data_func(client);
- if (IS_ERR(flash->pdata))
- return PTR_ERR(flash->pdata);
+ if (IS_ERR(flash->pdata)) {
+ ret = PTR_ERR(flash->pdata);
+ goto err_free_flash;
+ }

v4l2_i2c_subdev_init(&flash->sd, client, &lm3554_ops);
flash->sd.internal_ops = &lm3554_internal_ops;
flash->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
flash->mode = ATOMISP_FLASH_MODE_OFF;
flash->timeout = LM3554_MAX_TIMEOUT / LM3554_TIMEOUT_STEPSIZE - 1;
- ret =
- v4l2_ctrl_handler_init(&flash->ctrl_handler,
- ARRAY_SIZE(lm3554_controls));
+ ret = v4l2_ctrl_handler_init(&flash->ctrl_handler,
+ ARRAY_SIZE(lm3554_controls));
if (ret) {
- dev_err(&client->dev, "error initialize a ctrl_handler.\n");
- goto fail2;
+ dev_err(&client->dev, "error initializing ctrl_handler");
+ goto err_unregister_sd;
}

for (i = 0; i < ARRAY_SIZE(lm3554_controls); i++)
v4l2_ctrl_new_custom(&flash->ctrl_handler, &lm3554_controls[i],
NULL);

- if (flash->ctrl_handler.error) {
- dev_err(&client->dev, "ctrl_handler error.\n");
- goto fail2;
+ ret = flash->ctrl_handler.error;
+ if (ret) {
+ dev_err(&client->dev, "ctrl_handler error");
+ goto err_free_ctrl_handler;
}

flash->sd.ctrl_handler = &flash->ctrl_handler;
- err = media_entity_pads_init(&flash->sd.entity, 0, NULL);
- if (err) {
- dev_err(&client->dev, "error initialize a media entity.\n");
- goto fail1;
+ ret = media_entity_pads_init(&flash->sd.entity, 0, NULL);
+ if (ret) {
+ dev_err(&client->dev, "error initializing media entity");
+ goto err_free_ctrl_handler;
}

flash->sd.entity.function = MEDIA_ENT_F_FLASH;
@@ -881,20 +882,26 @@ static int lm3554_probe(struct i2c_client *client)

timer_setup(&flash->flash_off_delay, lm3554_flash_off_delay, 0);

- err = lm3554_gpio_init(client);
- if (err) {
+ ret = lm3554_gpio_init(client);
+ if (ret) {
dev_err(&client->dev, "gpio request/direction_output fail");
- goto fail2;
+ goto err_del_timer;
}
- return atomisp_register_i2c_module(&flash->sd, NULL, LED_FLASH);
-fail2:
+
+ ret = atomisp_register_i2c_module(&flash->sd, NULL, LED_FLASH);
+ if (!ret)
+ return 0;
+
+err_del_timer:
+ del_timer_sync(&flash->flash_off_delay);
media_entity_cleanup(&flash->sd.entity);
+err_free_ctrl_handler:
v4l2_ctrl_handler_free(&flash->ctrl_handler);
-fail1:
+err_unregister_sd:
v4l2_device_unregister_subdev(&flash->sd);
+err_free_flash:
kfree(flash);
-
- return err;
+ return ret;
}

static int lm3554_remove(struct i2c_client *client)
--
2.28.0

2020-09-04 06:37:02

by Dan Carpenter

[permalink] [raw]
Subject: Re: [PATCH v2] staging: media: atomisp: Fix error path in lm3554_probe()

On Thu, Sep 03, 2020 at 07:24:51PM +0100, Alex Dewar wrote:
> +
> + ret = atomisp_register_i2c_module(&flash->sd, NULL, LED_FLASH);
> + if (!ret)
> + return 0;

Ugh!!! This is a a special case of the "success handling instead of
failure handling" anti-pattern where the last condition in the function
is different. I just fixed a bug caused by this on Wed.

https://www.spinics.net/lists/netdev/msg680226.html

But it doesn't cause any problems here so whatever...

Reviewed-by: Dan Carpenter <[email protected]>

regards,
dan carpenter

2020-09-19 19:54:31

by Alex Dewar

[permalink] [raw]
Subject: Re: [PATCH v2] staging: media: atomisp: Fix error path in lm3554_probe()

On 2020-09-03 19:24, Alex Dewar wrote:
> The error path for lm3554_probe() contains a number of bugs, including:
> * resource leaks
> * jumping to error labels out of sequence
> * not setting the return value appropriately
Ping?
>
> Fix it up and give the labels more memorable names.
>
> This issue has existed since the code was originally contributed in
> commit a49d25364dfb ("staging/atomisp: Add support for the Intel IPU v2"),
> although the code was subsequently removed altogether and then
> reinstated with commit ad85094b293e ("Revert "media: staging: atomisp: Remove driver"").
>
> Addresses-Coverity: 1496802 ("Resource leaks")
> Fixes: a49d25364dfb ("staging/atomisp: Add support for the Intel IPU v2")
> Signed-off-by: Alex Dewar <[email protected]>
> ---
> .../media/atomisp/i2c/atomisp-lm3554.c | 53 +++++++++++--------
> 1 file changed, 30 insertions(+), 23 deletions(-)
>
> diff --git a/drivers/staging/media/atomisp/i2c/atomisp-lm3554.c b/drivers/staging/media/atomisp/i2c/atomisp-lm3554.c
> index 7ca7378b1859..cca10a4c2db0 100644
> --- a/drivers/staging/media/atomisp/i2c/atomisp-lm3554.c
> +++ b/drivers/staging/media/atomisp/i2c/atomisp-lm3554.c
> @@ -833,7 +833,6 @@ static void *lm3554_platform_data_func(struct i2c_client *client)
>
> static int lm3554_probe(struct i2c_client *client)
> {
> - int err = 0;
> struct lm3554 *flash;
> unsigned int i;
> int ret;
> @@ -843,36 +842,38 @@ static int lm3554_probe(struct i2c_client *client)
> return -ENOMEM;
>
> flash->pdata = lm3554_platform_data_func(client);
> - if (IS_ERR(flash->pdata))
> - return PTR_ERR(flash->pdata);
> + if (IS_ERR(flash->pdata)) {
> + ret = PTR_ERR(flash->pdata);
> + goto err_free_flash;
> + }
>
> v4l2_i2c_subdev_init(&flash->sd, client, &lm3554_ops);
> flash->sd.internal_ops = &lm3554_internal_ops;
> flash->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
> flash->mode = ATOMISP_FLASH_MODE_OFF;
> flash->timeout = LM3554_MAX_TIMEOUT / LM3554_TIMEOUT_STEPSIZE - 1;
> - ret =
> - v4l2_ctrl_handler_init(&flash->ctrl_handler,
> - ARRAY_SIZE(lm3554_controls));
> + ret = v4l2_ctrl_handler_init(&flash->ctrl_handler,
> + ARRAY_SIZE(lm3554_controls));
> if (ret) {
> - dev_err(&client->dev, "error initialize a ctrl_handler.\n");
> - goto fail2;
> + dev_err(&client->dev, "error initializing ctrl_handler");
> + goto err_unregister_sd;
> }
>
> for (i = 0; i < ARRAY_SIZE(lm3554_controls); i++)
> v4l2_ctrl_new_custom(&flash->ctrl_handler, &lm3554_controls[i],
> NULL);
>
> - if (flash->ctrl_handler.error) {
> - dev_err(&client->dev, "ctrl_handler error.\n");
> - goto fail2;
> + ret = flash->ctrl_handler.error;
> + if (ret) {
> + dev_err(&client->dev, "ctrl_handler error");
> + goto err_free_ctrl_handler;
> }
>
> flash->sd.ctrl_handler = &flash->ctrl_handler;
> - err = media_entity_pads_init(&flash->sd.entity, 0, NULL);
> - if (err) {
> - dev_err(&client->dev, "error initialize a media entity.\n");
> - goto fail1;
> + ret = media_entity_pads_init(&flash->sd.entity, 0, NULL);
> + if (ret) {
> + dev_err(&client->dev, "error initializing media entity");
> + goto err_free_ctrl_handler;
> }
>
> flash->sd.entity.function = MEDIA_ENT_F_FLASH;
> @@ -881,20 +882,26 @@ static int lm3554_probe(struct i2c_client *client)
>
> timer_setup(&flash->flash_off_delay, lm3554_flash_off_delay, 0);
>
> - err = lm3554_gpio_init(client);
> - if (err) {
> + ret = lm3554_gpio_init(client);
> + if (ret) {
> dev_err(&client->dev, "gpio request/direction_output fail");
> - goto fail2;
> + goto err_del_timer;
> }
> - return atomisp_register_i2c_module(&flash->sd, NULL, LED_FLASH);
> -fail2:
> +
> + ret = atomisp_register_i2c_module(&flash->sd, NULL, LED_FLASH);
> + if (!ret)
> + return 0;
> +
> +err_del_timer:
> + del_timer_sync(&flash->flash_off_delay);
> media_entity_cleanup(&flash->sd.entity);
> +err_free_ctrl_handler:
> v4l2_ctrl_handler_free(&flash->ctrl_handler);
> -fail1:
> +err_unregister_sd:
> v4l2_device_unregister_subdev(&flash->sd);
> +err_free_flash:
> kfree(flash);
> -
> - return err;
> + return ret;
> }
>
> static int lm3554_remove(struct i2c_client *client)