* [PATCH] usbip: vudc synchronize sysfs code paths
@ 2021-04-26 17:28 Tom Seewald
2021-04-30 13:46 ` Greg Kroah-Hartman
0 siblings, 1 reply; 2+ messages in thread
From: Tom Seewald @ 2021-04-26 17:28 UTC (permalink / raw)
To: stable
Cc: tseewald, Shuah Khan, syzbot+a93fba6d384346a761e3,
Greg Kroah-Hartman, Valentina Manea, Shuah Khan
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 # 4.14.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
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH] usbip: vudc synchronize sysfs code paths
2021-04-26 17:28 [PATCH] usbip: vudc synchronize sysfs code paths Tom Seewald
@ 2021-04-30 13:46 ` Greg Kroah-Hartman
0 siblings, 0 replies; 2+ messages in thread
From: Greg Kroah-Hartman @ 2021-04-30 13:46 UTC (permalink / raw)
To: Tom Seewald
Cc: stable, Shuah Khan, syzbot+a93fba6d384346a761e3, Valentina Manea,
Shuah Khan
On Mon, Apr 26, 2021 at 12:28:31PM -0500, Tom Seewald wrote:
> 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 # 4.14.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(+)
Now queued up, thanks.
greg k-h
^ permalink raw reply [flat|nested] 2+ messages in thread
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