--- /dev/null
+From bd8b82042269a95db48074b8bb400678dbac1815 Mon Sep 17 00:00:00 2001
+From: Shuah Khan <skhan@linuxfoundation.org>
+Date: Mon, 29 Mar 2021 19:36:50 -0600
+Subject: usbip: vudc synchronize sysfs code paths
+
+From: Shuah Khan <skhan@linuxfoundation.org>
+
+commit bd8b82042269a95db48074b8bb400678dbac1815 upstream.
+
+Fuzzing uncovered race condition between sysfs code paths in usbip
+drivers. Device connect/disconnect code paths initiated through
+sysfs interface are prone to races if disconnect happens during
+connect and vice versa.
+
+Use sysfs_lock to protect sysfs paths in vudc.
+
+Cc: stable@vger.kernel.org
+Reported-and-tested-by: syzbot+a93fba6d384346a761e3@syzkaller.appspotmail.com
+Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
+Link: https://lore.kernel.org/r/caabcf3fc87bdae970509b5ff32d05bb7ce2fb15.1616807117.git.skhan@linuxfoundation.org
+Signed-off-by: Tom Seewald <tseewald@gmail.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ drivers/usb/usbip/vudc_dev.c | 1 +
+ drivers/usb/usbip/vudc_sysfs.c | 5 +++++
+ 2 files changed, 6 insertions(+)
+
+--- a/drivers/usb/usbip/vudc_dev.c
++++ b/drivers/usb/usbip/vudc_dev.c
+@@ -586,6 +586,7 @@ static int init_vudc_hw(struct vudc *udc
+ init_waitqueue_head(&udc->tx_waitq);
+
+ spin_lock_init(&ud->lock);
++ mutex_init(&ud->sysfs_lock);
+ ud->status = SDEV_ST_AVAILABLE;
+ ud->side = USBIP_VUDC;
+
+--- a/drivers/usb/usbip/vudc_sysfs.c
++++ b/drivers/usb/usbip/vudc_sysfs.c
+@@ -125,6 +125,7 @@ static ssize_t store_sockfd(struct devic
+ dev_err(dev, "no device");
+ return -ENODEV;
+ }
++ mutex_lock(&udc->ud.sysfs_lock);
+ spin_lock_irqsave(&udc->lock, flags);
+ /* Don't export what we don't have */
+ if (!udc->driver || !udc->pullup) {
+@@ -200,6 +201,8 @@ static ssize_t store_sockfd(struct devic
+
+ wake_up_process(udc->ud.tcp_rx);
+ wake_up_process(udc->ud.tcp_tx);
++
++ mutex_unlock(&udc->ud.sysfs_lock);
+ return count;
+
+ } else {
+@@ -220,6 +223,7 @@ static ssize_t store_sockfd(struct devic
+ }
+
+ spin_unlock_irqrestore(&udc->lock, flags);
++ mutex_unlock(&udc->ud.sysfs_lock);
+
+ return count;
+
+@@ -229,6 +233,7 @@ unlock_ud:
+ spin_unlock_irq(&udc->ud.lock);
+ unlock:
+ spin_unlock_irqrestore(&udc->lock, flags);
++ mutex_unlock(&udc->ud.sysfs_lock);
+
+ return ret;
+ }