Re: WARNING in _chaoskey_fill/usb_submit_urb

[Oliver Neukum]

Am Montag, den 23.09.2019, 07:31 -0700 schrieb syzbot:
> Hello,
> 
> syzbot found the following crash on:
> 
> HEAD commit:    e0bd8d79 usb-fuzzer: main usb gadget fuzzer driver
> git tree:       https://github.com/google/kasan.git usb-fuzzer
> console output: https://syzkaller.appspot.com/x/log.txt?x=1452c6a1600000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=8847e5384a16f66a
> dashboard link: https://syzkaller.appspot.com/bug?extid=f5349b421c6213d34ce2
> compiler:       gcc (GCC) 9.0.0 20181231 (experimental)
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=16342d45600000
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=166769b1600000
> 
> IMPORTANT: if you fix the bug, please add the following tag to the commit:
> Reported-by: syzbot+f5349b421c6213d34ce2@xxxxxxxxxxxxxxxxxxxxxxxxx

#syz test: https://github.com/google/kasan.git e0bd8d79
From b80b39a2565a80f16ce007982babe753e225ea83 Mon Sep 17 00:00:00 2001
From: Oliver Neukum <oneukum@xxxxxxxx>
Date: Mon, 30 Sep 2019 15:19:13 +0200
Subject: [PATCH] USB: chaoskey: fix error case of a timeout

In case of a timeout communication with the device needs to be ended
from the host side, lest we overwrite an active URB

Signed-off-by: Oliver Neukum <oneukum@xxxxxxx>
---
 drivers/usb/misc/chaoskey.c | 17 ++++++++++++++---
 1 file changed, 14 insertions(+), 3 deletions(-)

diff --git a/drivers/usb/misc/chaoskey.c b/drivers/usb/misc/chaoskey.c
index cf5828ce927a..3cb7e1b7d454 100644
--- a/drivers/usb/misc/chaoskey.c
+++ b/drivers/usb/misc/chaoskey.c
@@ -383,13 +383,17 @@ static int _chaoskey_fill(struct chaoskey *dev)
 		!dev->reading,
 		(started ? NAK_TIMEOUT : ALEA_FIRST_TIMEOUT) );
 
-	if (result < 0)
+	if (result < 0) {
+		usb_kill_urb(dev->urb);
 		goto out;
+	}
 
-	if (result == 0)
+	if (result == 0) {
 		result = -ETIMEDOUT;
-	else
+		usb_kill_urb(dev->urb);
+	} else {
 		result = dev->valid;
+	}
 out:
 	/* Let the device go back to sleep eventually */
 	usb_autopm_put_interface(dev->interface);
@@ -525,7 +529,14 @@ static int chaoskey_suspend(struct usb_interface *interface,
 
 static int chaoskey_resume(struct usb_interface *interface)
 {
+	struct chaoskey *dev;
+	struct usb_device *udev = interface_to_usbdev(interface);
+
 	usb_dbg(interface, "resume");
+	dev = usb_get_intfdata(interface);
+	if (le16_to_cpu(udev->descriptor.idVendor) == ALEA_VENDOR_ID)
+		dev->reads_started = false;
+
 	return 0;
 }
 #else
-- 
2.16.4