This is a note to let you know that I've just added the patch titled
usbip: usbip_host: fix stub_dev lock context imbalance regression
to my usb git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git
in the usb-linus branch.
The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)
The patch will hopefully also be merged in Linus's tree for the
next -rc kernel release.
If you have any questions about this process, please let me know.
>From 3ea3091f1bd8586125848c62be295910e9802af0 Mon Sep 17 00:00:00 2001
From: Shuah Khan <skhan@xxxxxxxxxxxxxxxxxxx>
Date: Wed, 29 May 2019 13:46:15 -0600
Subject: usbip: usbip_host: fix stub_dev lock context imbalance regression
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Fix the following sparse context imbalance regression introduced in
a patch that fixed sleeping function called from invalid context bug.
kbuild test robot reported on:
tree/branch: https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-linus
Regressions in current branch:
drivers/usb/usbip/stub_dev.c:399:9: sparse: sparse: context imbalance in 'stub_probe' - different lock contexts for basic block
drivers/usb/usbip/stub_dev.c:418:13: sparse: sparse: context imbalance in 'stub_disconnect' - different lock contexts for basic block
drivers/usb/usbip/stub_dev.c:464:1-10: second lock on line 476
Error ids grouped by kconfigs:
recent_errors
├── i386-allmodconfig
│ └── drivers-usb-usbip-stub_dev.c:second-lock-on-line
├── x86_64-allmodconfig
│ ├── drivers-usb-usbip-stub_dev.c:sparse:sparse:context-imbalance-in-stub_disconnect-different-lock-contexts-for-basic-block
│ └── drivers-usb-usbip-stub_dev.c:sparse:sparse:context-imbalance-in-stub_probe-different-lock-contexts-for-basic-block
└── x86_64-allyesconfig
└── drivers-usb-usbip-stub_dev.c:second-lock-on-line
This is a real problem in an error leg where spin_lock() is called on an
already held lock.
Fix the imbalance in stub_probe() and stub_disconnect().
Signed-off-by: Shuah Khan <skhan@xxxxxxxxxxxxxxxxxxx>
Fixes: 0c9e8b3cad65 ("usbip: usbip_host: fix BUG: sleeping function called from invalid context")
Cc: stable <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/usb/usbip/stub_dev.c | 36 +++++++++++++++++++++++-------------
1 file changed, 23 insertions(+), 13 deletions(-)
diff --git a/drivers/usb/usbip/stub_dev.c b/drivers/usb/usbip/stub_dev.c
index d094c96643d2..7931e6cecc70 100644
--- a/drivers/usb/usbip/stub_dev.c
+++ b/drivers/usb/usbip/stub_dev.c
@@ -326,14 +326,17 @@ static int stub_probe(struct usb_device *udev)
* See driver_probe_device() in driver/base/dd.c
*/
rc = -ENODEV;
- goto sdev_free;
+ if (!busid_priv)
+ goto sdev_free;
+
+ goto call_put_busid_priv;
}
if (udev->descriptor.bDeviceClass == USB_CLASS_HUB) {
dev_dbg(&udev->dev, "%s is a usb hub device... skip!\n",
udev_busid);
rc = -ENODEV;
- goto sdev_free;
+ goto call_put_busid_priv;
}
if (!strcmp(udev->bus->bus_name, "vhci_hcd")) {
@@ -342,7 +345,7 @@ static int stub_probe(struct usb_device *udev)
udev_busid);
rc = -ENODEV;
- goto sdev_free;
+ goto call_put_busid_priv;
}
@@ -361,6 +364,9 @@ static int stub_probe(struct usb_device *udev)
save_status = busid_priv->status;
busid_priv->status = STUB_BUSID_ALLOC;
+ /* release the busid_lock */
+ put_busid_priv(busid_priv);
+
/*
* Claim this hub port.
* It doesn't matter what value we pass as owner
@@ -373,9 +379,6 @@ static int stub_probe(struct usb_device *udev)
goto err_port;
}
- /* release the busid_lock */
- put_busid_priv(busid_priv);
-
rc = stub_add_files(&udev->dev);
if (rc) {
dev_err(&udev->dev, "stub_add_files for %s\n", udev_busid);
@@ -395,11 +398,17 @@ static int stub_probe(struct usb_device *udev)
spin_lock(&busid_priv->busid_lock);
busid_priv->sdev = NULL;
busid_priv->status = save_status;
-sdev_free:
- stub_device_free(sdev);
+ spin_unlock(&busid_priv->busid_lock);
+ /* lock is released - go to free */
+ goto sdev_free;
+
+call_put_busid_priv:
/* release the busid_lock */
put_busid_priv(busid_priv);
+sdev_free:
+ stub_device_free(sdev);
+
return rc;
}
@@ -435,7 +444,9 @@ static void stub_disconnect(struct usb_device *udev)
/* get stub_device */
if (!sdev) {
dev_err(&udev->dev, "could not get device");
- goto call_put_busid_priv;
+ /* release busid_lock */
+ put_busid_priv(busid_priv);
+ return;
}
dev_set_drvdata(&udev->dev, NULL);
@@ -465,7 +476,7 @@ static void stub_disconnect(struct usb_device *udev)
if (!busid_priv->shutdown_busid)
busid_priv->shutdown_busid = 1;
/* release busid_lock */
- put_busid_priv(busid_priv);
+ spin_unlock(&busid_priv->busid_lock);
/* shutdown the current connection */
shutdown_busid(busid_priv);
@@ -480,10 +491,9 @@ static void stub_disconnect(struct usb_device *udev)
if (busid_priv->status == STUB_BUSID_ALLOC)
busid_priv->status = STUB_BUSID_ADDED;
-
-call_put_busid_priv:
/* release busid_lock */
- put_busid_priv(busid_priv);
+ spin_unlock(&busid_priv->busid_lock);
+ return;
}
#ifdef CONFIG_PM
--
2.21.0
