Skip to contentSkip to conversation

FAILED: patch "[PATCH] usbip: vudc synchronize sysfs code paths" failed to apply to 4.9-stable tree

PATCH [email protected] 1 participant 1 message Apr 11, 2021

Subsystems (3)
Stable branch USB USB over IP driver
lore
Share & tools
lore

[email protected]

author maintainer
#0 lore raw

The patch below does not apply to the 4.9-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From bd8b82042269a95db48074b8bb400678dbac1815 Mon Sep 17 00:00:00 2001
From: Shuah Khan <[email protected]>
Date: Mon, 29 Mar 2021 19:36:50 -0600
Subject: [PATCH] usbip: vudc synchronize sysfs code paths

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 [email protected]
Reported-and-tested-by [email protected]
Signed-off-by Shuah Khan <[email protected]>
Link https://lore.kernel.org/r/caabcf3fc87bdae970509b5ff32d05bb7ce2fb15.1616807117.git.skhan@linuxfoundation.org open here
Signed-off-by Greg Kroah-Hartman <[email protected]>
drivers/usb/usbip/vudc_dev.c +1 -0
index c8eeabdd9b56..2bc428f2e261 100644
@@ -572,6 +572,7 @@ 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;
drivers/usb/usbip/vudc_sysfs.c +5 -0
index 7383a543c6d1..f7633ee655a1 100644
@@ -112,6 +112,7 @@ static ssize_t usbip_sockfd_store(struct device *dev,
 		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) {

@@ -187,6 +188,8 @@ static ssize_t usbip_sockfd_store(struct device *dev,
 
 		wake_up_process(udc->ud.tcp_rx);
 		wake_up_process(udc->ud.tcp_tx);
+
+		mutex_unlock(&udc->ud.sysfs_lock);
 		return count;
 
 	} else {

@@ -207,6 +210,7 @@ static ssize_t usbip_sockfd_store(struct device *dev,
 	}
 
 	spin_unlock_irqrestore(&udc->lock, flags);
+	mutex_unlock(&udc->ud.sysfs_lock);
 
 	return count;
 

@@ -216,6 +220,7 @@ static ssize_t usbip_sockfd_store(struct device *dev,
 	spin_unlock_irq(&udc->ud.lock);
 unlock:
 	spin_unlock_irqrestore(&udc->lock, flags);
+	mutex_unlock(&udc->ud.sysfs_lock);
 
 	return ret;
 }