This is a note to let you know that I've just added the patch titled
usbip: vudc synchronize sysfs code paths
to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
usbip-vudc-synchronize-sysfs-code-paths.patch
and it can be found in the queue-4.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From foo@baz Tue Apr 20 01:51:40 PM CEST 2021
From: Tom Seewald <tseewald@xxxxxxxxx>
Date: Fri, 16 Apr 2021 15:53:18 -0500
Subject: usbip: vudc synchronize sysfs code paths
To: stable@xxxxxxxxxxxxxxx
Cc: Shuah Khan <skhan@xxxxxxxxxxxxxxxxxxx>, syzbot+a93fba6d384346a761e3@xxxxxxxxxxxxxxxxxxxxxxxxx, Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>, Tom Seewald <tseewald@xxxxxxxxx>, Valentina Manea <valentina.manea.m@xxxxxxxxx>, Shuah Khan <shuah@xxxxxxxxxx>
Message-ID: <20210416205319.14075-3-tseewald@xxxxxxxxx>
From: Shuah Khan <skhan@xxxxxxxxxxxxxxxxxxx>
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@xxxxxxxxxxxxxxx # 4.9.x # 4.14.x
Reported-and-tested-by: syzbot+a93fba6d384346a761e3@xxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Shuah Khan <skhan@xxxxxxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/caabcf3fc87bdae970509b5ff32d05bb7ce2fb15.1616807117.git.skhan@xxxxxxxxxxxxxxxxxxx
Signed-off-by: Tom Seewald <tseewald@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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
@@ -582,6 +582,7 @@ 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;
}
Patches currently in stable-queue which might be from tseewald@xxxxxxxxx are
queue-4.9/usbip-vudc-synchronize-sysfs-code-paths.patch
queue-4.9/usbip-fix-incorrect-double-assignment-to-udc-ud.tcp_rx.patch
queue-4.9/usbip-synchronize-event-handler-with-sysfs-code-paths.patch
queue-4.9/usbip-add-sysfs_lock-to-synchronize-sysfs-code-paths.patch
queue-4.9/usbip-stub-dev-synchronize-sysfs-code-paths.patch
