2024-01-12 14:34:32

by Dan Carpenter

[permalink] [raw]
Subject: [PATCH 1/2] HID: hid-steam: remove pointless error message

This error message doesn't really add any information. If modprobe
fails then the user will already know what the error code is. In the
case of kmalloc() it's a style violation to print an error message for
that because kmalloc has it's own better error messages built in.

Signed-off-by: Dan Carpenter <[email protected]>
---
drivers/hid/hid-steam.c | 10 +++-------
1 file changed, 3 insertions(+), 7 deletions(-)

diff --git a/drivers/hid/hid-steam.c b/drivers/hid/hid-steam.c
index b3c4e50e248a..59df6ead7b54 100644
--- a/drivers/hid/hid-steam.c
+++ b/drivers/hid/hid-steam.c
@@ -1109,10 +1109,9 @@ static int steam_probe(struct hid_device *hdev,
return hid_hw_start(hdev, HID_CONNECT_DEFAULT);

steam = devm_kzalloc(&hdev->dev, sizeof(*steam), GFP_KERNEL);
- if (!steam) {
- ret = -ENOMEM;
- goto steam_alloc_fail;
- }
+ if (!steam)
+ return -ENOMEM;
+
steam->hdev = hdev;
hid_set_drvdata(hdev, steam);
spin_lock_init(&steam->lock);
@@ -1179,9 +1178,6 @@ static int steam_probe(struct hid_device *hdev,
cancel_work_sync(&steam->work_connect);
cancel_delayed_work_sync(&steam->mode_switch);
cancel_work_sync(&steam->rumble_work);
-steam_alloc_fail:
- hid_err(hdev, "%s: failed with error %d\n",
- __func__, ret);
return ret;
}

--
2.43.0



2024-01-12 14:35:24

by Dan Carpenter

[permalink] [raw]
Subject: [PATCH 2/2] HID: hid-steam: Fix cleanup in probe()

There are a number of issues in this code. First of all if
steam_create_client_hid() fails then it leads to an error pointer
dereference when we call hid_destroy_device(steam->client_hdev).

Also there are a number of leaks. hid_hw_stop() is not called if
hid_hw_open() fails for example. And it doesn't call steam_unregister()
or hid_hw_close().

Fixes: 691ead124a0c ("HID: hid-steam: Clean up locking")
Signed-off-by: Dan Carpenter <[email protected]>
---
This is just from static analysis and code review. I haven't tested
it. I only included the fixes tag for the error pointer dereference.

drivers/hid/hid-steam.c | 26 +++++++++++++++-----------
1 file changed, 15 insertions(+), 11 deletions(-)

diff --git a/drivers/hid/hid-steam.c b/drivers/hid/hid-steam.c
index 59df6ead7b54..b08a5ab58528 100644
--- a/drivers/hid/hid-steam.c
+++ b/drivers/hid/hid-steam.c
@@ -1128,14 +1128,14 @@ static int steam_probe(struct hid_device *hdev,
*/
ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT & ~HID_CONNECT_HIDRAW);
if (ret)
- goto hid_hw_start_fail;
+ goto err_cancel_work;

ret = hid_hw_open(hdev);
if (ret) {
hid_err(hdev,
"%s:hid_hw_open\n",
__func__);
- goto hid_hw_open_fail;
+ goto err_hw_stop;
}

if (steam->quirks & STEAM_QUIRK_WIRELESS) {
@@ -1151,33 +1151,37 @@ static int steam_probe(struct hid_device *hdev,
hid_err(hdev,
"%s:steam_register failed with error %d\n",
__func__, ret);
- goto input_register_fail;
+ goto err_hw_close;
}
}

steam->client_hdev = steam_create_client_hid(hdev);
if (IS_ERR(steam->client_hdev)) {
ret = PTR_ERR(steam->client_hdev);
- goto client_hdev_fail;
+ goto err_stream_unregister;
}
steam->client_hdev->driver_data = steam;

ret = hid_add_device(steam->client_hdev);
if (ret)
- goto client_hdev_add_fail;
+ goto err_destroy;

return 0;

-client_hdev_add_fail:
- hid_hw_stop(hdev);
-client_hdev_fail:
+err_destroy:
hid_destroy_device(steam->client_hdev);
-input_register_fail:
-hid_hw_open_fail:
-hid_hw_start_fail:
+err_stream_unregister:
+ if (steam->connected)
+ steam_unregister(steam);
+err_hw_close:
+ hid_hw_close(hdev);
+err_hw_stop:
+ hid_hw_stop(hdev);
+err_cancel_work:
cancel_work_sync(&steam->work_connect);
cancel_delayed_work_sync(&steam->mode_switch);
cancel_work_sync(&steam->rumble_work);
+
return ret;
}

--
2.43.0


2024-01-13 02:11:25

by Vicki Pfau

[permalink] [raw]
Subject: Re: [PATCH 2/2] HID: hid-steam: Fix cleanup in probe()

I have applied this to our downstream and made sure it compiles and runs
without obvious issues.

Reviewed-by: Vicki Pfau <[email protected]>

Thanks,
Vicki

On 1/12/24 06:35, Dan Carpenter wrote:
> There are a number of issues in this code. First of all if
> steam_create_client_hid() fails then it leads to an error pointer
> dereference when we call hid_destroy_device(steam->client_hdev).
>
> Also there are a number of leaks. hid_hw_stop() is not called if
> hid_hw_open() fails for example. And it doesn't call steam_unregister()
> or hid_hw_close().
>
> Fixes: 691ead124a0c ("HID: hid-steam: Clean up locking")
> Signed-off-by: Dan Carpenter <[email protected]>
> ---
> This is just from static analysis and code review. I haven't tested
> it. I only included the fixes tag for the error pointer dereference.
>
> drivers/hid/hid-steam.c | 26 +++++++++++++++-----------
> 1 file changed, 15 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/hid/hid-steam.c b/drivers/hid/hid-steam.c
> index 59df6ead7b54..b08a5ab58528 100644
> --- a/drivers/hid/hid-steam.c
> +++ b/drivers/hid/hid-steam.c
> @@ -1128,14 +1128,14 @@ static int steam_probe(struct hid_device *hdev,
> */
> ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT & ~HID_CONNECT_HIDRAW);
> if (ret)
> - goto hid_hw_start_fail;
> + goto err_cancel_work;
>
> ret = hid_hw_open(hdev);
> if (ret) {
> hid_err(hdev,
> "%s:hid_hw_open\n",
> __func__);
> - goto hid_hw_open_fail;
> + goto err_hw_stop;
> }
>
> if (steam->quirks & STEAM_QUIRK_WIRELESS) {
> @@ -1151,33 +1151,37 @@ static int steam_probe(struct hid_device *hdev,
> hid_err(hdev,
> "%s:steam_register failed with error %d\n",
> __func__, ret);
> - goto input_register_fail;
> + goto err_hw_close;
> }
> }
>
> steam->client_hdev = steam_create_client_hid(hdev);
> if (IS_ERR(steam->client_hdev)) {
> ret = PTR_ERR(steam->client_hdev);
> - goto client_hdev_fail;
> + goto err_stream_unregister;
> }
> steam->client_hdev->driver_data = steam;
>
> ret = hid_add_device(steam->client_hdev);
> if (ret)
> - goto client_hdev_add_fail;
> + goto err_destroy;
>
> return 0;
>
> -client_hdev_add_fail:
> - hid_hw_stop(hdev);
> -client_hdev_fail:
> +err_destroy:
> hid_destroy_device(steam->client_hdev);
> -input_register_fail:
> -hid_hw_open_fail:
> -hid_hw_start_fail:
> +err_stream_unregister:
> + if (steam->connected)
> + steam_unregister(steam);
> +err_hw_close:
> + hid_hw_close(hdev);
> +err_hw_stop:
> + hid_hw_stop(hdev);
> +err_cancel_work:
> cancel_work_sync(&steam->work_connect);
> cancel_delayed_work_sync(&steam->mode_switch);
> cancel_work_sync(&steam->rumble_work);
> +
> return ret;
> }
>

2024-01-15 13:45:38

by Benjamin Tissoires

[permalink] [raw]
Subject: Re: [PATCH 1/2] HID: hid-steam: remove pointless error message

On Fri, 12 Jan 2024 17:34:14 +0300, Dan Carpenter wrote:
> This error message doesn't really add any information. If modprobe
> fails then the user will already know what the error code is. In the
> case of kmalloc() it's a style violation to print an error message for
> that because kmalloc has it's own better error messages built in.
>
>

Applied to https://git.kernel.org/pub/scm/linux/kernel/git/hid/hid.git (for-6.8/upstream-fixes), thanks!

[1/2] HID: hid-steam: remove pointless error message
https://git.kernel.org/hid/hid/c/a96681699611
[2/2] HID: hid-steam: Fix cleanup in probe()
https://git.kernel.org/hid/hid/c/a9f1da09c69f

Cheers,
--
Benjamin Tissoires <[email protected]>