[2/7] Input: aiptek: fix endpoint sanity check
diff mbox series

Message ID 20191210113737.4016-3-johan@kernel.org
State Mainlined
Commit 3111491fca4f01764e0c158c5e0f7ced808eef51
Headers show
Series
  • Input: fix USB alsetting bugs
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Commit Message

Johan Hovold Dec. 10, 2019, 11:37 a.m. UTC
The driver was checking the number of endpoints of the first alternate
setting instead of the current one, something which could lead to the
driver binding to an invalid interface.

This in turn could cause the driver to misbehave or trigger a WARN() in
usb_submit_urb() that kernels with panic_on_warn set would choke on.

Fixes: 8e20cf2bce12 ("Input: aiptek - fix crash on detecting device without endpoints")
Cc: stable <stable@vger.kernel.org>     # 4.4
Cc: Vladis Dronov <vdronov@redhat.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
---
 drivers/input/tablet/aiptek.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

Comments

Vladis Dronov Dec. 11, 2019, 11:55 a.m. UTC | #1
A fix for a bug indeed, thank you Johan.

Best regards,
Vladis Dronov | Red Hat, Inc. | The Core Kernel | Senior Software Engineer

----- Original Message -----
> From: "Johan Hovold" <johan@kernel.org>
> To: "Dmitry Torokhov" <dmitry.torokhov@gmail.com>
> Cc: linux-input@vger.kernel.org, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, "Johan Hovold"
> <johan@kernel.org>, "stable" <stable@vger.kernel.org>, "Vladis Dronov" <vdronov@redhat.com>
> Sent: Tuesday, December 10, 2019 12:37:32 PM
> Subject: [PATCH 2/7] Input: aiptek: fix endpoint sanity check
> 
> The driver was checking the number of endpoints of the first alternate
> setting instead of the current one, something which could lead to the
> driver binding to an invalid interface.
> 
> This in turn could cause the driver to misbehave or trigger a WARN() in
> usb_submit_urb() that kernels with panic_on_warn set would choke on.
> 
> Fixes: 8e20cf2bce12 ("Input: aiptek - fix crash on detecting device without
> endpoints")
> Cc: stable <stable@vger.kernel.org>     # 4.4
> Cc: Vladis Dronov <vdronov@redhat.com>
> Signed-off-by: Johan Hovold <johan@kernel.org>

Patch
diff mbox series

diff --git a/drivers/input/tablet/aiptek.c b/drivers/input/tablet/aiptek.c
index 2ca586fb914f..06d0ffef4a17 100644
--- a/drivers/input/tablet/aiptek.c
+++ b/drivers/input/tablet/aiptek.c
@@ -1802,14 +1802,14 @@  aiptek_probe(struct usb_interface *intf, const struct usb_device_id *id)
 	input_set_abs_params(inputdev, ABS_WHEEL, AIPTEK_WHEEL_MIN, AIPTEK_WHEEL_MAX - 1, 0, 0);
 
 	/* Verify that a device really has an endpoint */
-	if (intf->altsetting[0].desc.bNumEndpoints < 1) {
+	if (intf->cur_altsetting->desc.bNumEndpoints < 1) {
 		dev_err(&intf->dev,
 			"interface has %d endpoints, but must have minimum 1\n",
-			intf->altsetting[0].desc.bNumEndpoints);
+			intf->cur_altsetting->desc.bNumEndpoints);
 		err = -EINVAL;
 		goto fail3;
 	}
-	endpoint = &intf->altsetting[0].endpoint[0].desc;
+	endpoint = &intf->cur_altsetting->endpoint[0].desc;
 
 	/* Go set up our URB, which is called when the tablet receives
 	 * input.