From: Tom Seewald <tseewald@gmail.com>
To: stable@vger.kernel.org
Cc: Shuah Khan <skhan@linuxfoundation.org>,
syzbot+a93fba6d384346a761e3@syzkaller.appspotmail.com,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Tom Seewald <tseewald@gmail.com>,
Valentina Manea <valentina.manea.m@gmail.com>,
Shuah Khan <shuah@kernel.org>
Subject: [PATCH 3/4] usbip: vudc synchronize sysfs code paths
Date: Fri, 16 Apr 2021 15:53:18 -0500 [thread overview]
Message-ID: <20210416205319.14075-3-tseewald@gmail.com> (raw)
In-Reply-To: <20210416205319.14075-1-tseewald@gmail.com>
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 # 4.9.x # 4.14.x
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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Tom Seewald <tseewald@gmail.com>
---
drivers/usb/usbip/vudc_dev.c | 1 +
drivers/usb/usbip/vudc_sysfs.c | 5 +++++
2 files changed, 6 insertions(+)
diff --git a/drivers/usb/usbip/vudc_dev.c b/drivers/usb/usbip/vudc_dev.c
index 7091848df6c8..d61b22bb1d8b 100644
--- 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;
diff --git a/drivers/usb/usbip/vudc_sysfs.c b/drivers/usb/usbip/vudc_sysfs.c
index f44d98eeb36a..e9d8dbd4e5a4 100644
--- a/drivers/usb/usbip/vudc_sysfs.c
+++ b/drivers/usb/usbip/vudc_sysfs.c
@@ -125,6 +125,7 @@ static ssize_t store_sockfd(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) {
@@ -200,6 +201,8 @@ static ssize_t store_sockfd(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 {
@@ -220,6 +223,7 @@ static ssize_t store_sockfd(struct device *dev,
}
spin_unlock_irqrestore(&udc->lock, flags);
+ mutex_unlock(&udc->ud.sysfs_lock);
return count;
@@ -229,6 +233,7 @@ static ssize_t store_sockfd(struct device *dev,
spin_unlock_irq(&udc->ud.lock);
unlock:
spin_unlock_irqrestore(&udc->lock, flags);
+ mutex_unlock(&udc->ud.sysfs_lock);
return ret;
}
--
2.20.1
next prev parent reply other threads:[~2021-04-16 20:53 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-16 20:53 [PATCH 1/4] usbip: add sysfs_lock to synchronize sysfs code paths Tom Seewald
2021-04-16 20:53 ` [PATCH 2/4] usbip: stub-dev " Tom Seewald
2021-04-16 21:44 ` Shuah Khan
2021-04-16 20:53 ` Tom Seewald [this message]
2021-04-16 21:45 ` [PATCH 3/4] usbip: vudc " Shuah Khan
2021-04-16 20:53 ` [PATCH 4/4] usbip: synchronize event handler with " Tom Seewald
2021-04-16 21:45 ` Shuah Khan
2021-04-16 21:43 ` [PATCH 1/4] usbip: add sysfs_lock to synchronize " Shuah Khan
2021-04-19 12:23 ` Greg Kroah-Hartman
2021-04-19 21:42 ` Shuah Khan
2021-04-20 7:30 ` Greg Kroah-Hartman
[not found] <cover.1616807117.git.skhan@linuxfoundation.org>
2021-03-30 1:36 ` [PATCH 3/4] usbip: vudc " Shuah Khan
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