Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
From:   Soumya Negi <soumya.negi97@gmail.com>
To:     Dmitry Torokhov <dmitry.torokhov@gmail.com>,
        Shuah Khan <skhan@linuxfoundation.org>
Cc:     Soumya Negi <soumya.negi97@gmail.com>,
        linux-kernel-mentees@lists.linuxfoundation.org,
        linux-input@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH] Input: Check sanity of endpoint in pegasus_open()
Date:   Mon, 29 Aug 2022 05:39:59 -0700
Message-Id: <20220829123959.21298-1-soumya.negi97@gmail.com>
Precedence: bulk

Fix WARNING in pegasus_open/usb_submit_urb
Syzbot bug: https://syzkaller.appspot.com/bug?id=bbc107584dcf3262253ce93183e51f3612aaeb13

Add sanity check of endpoint for Pegasus URB in pegasus_open() so that
transfer requests for bogus URBs are not submitted. If the URB is bogus
pegasus_open() will fail.

Reported-by: syzbot+04ee0cb4caccaed12d78@syzkaller.appspotmail.com
Signed-off-by: Soumya Negi <soumya.negi97@gmail.com>
---
 drivers/input/tablet/pegasus_notetaker.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/drivers/input/tablet/pegasus_notetaker.c b/drivers/input/tablet/pegasus_notetaker.c
index c608ac505d1b..5e47882ee4c0 100644
--- a/drivers/input/tablet/pegasus_notetaker.c
+++ b/drivers/input/tablet/pegasus_notetaker.c
@@ -225,6 +225,15 @@ static int pegasus_open(struct input_dev *dev)
 
 	mutex_lock(&pegasus->pm_mutex);
 	pegasus->irq->dev = pegasus->usbdev;
+
+	/* Sanity check of endpoint in Pegasus URB */
+	error = usb_urb_ep_type_check(pegasus->irq);
+	if (error) {
+		dev_err(&pegasus->usbdev->dev,
+			"URB failed endpoint sanity check: %d\n", error);
+		goto err_autopm_put;
+	}
+
 	if (usb_submit_urb(pegasus->irq, GFP_KERNEL)) {
 		error = -EIO;
 		goto err_autopm_put;
-- 
2.17.1