svn commit: r260814 - head/sys/dev/usb
Hans Petter Selasky
hselasky at FreeBSD.org
Fri Jan 17 10:35:19 UTC 2014
Author: hselasky
Date: Fri Jan 17 10:35:18 2014
New Revision: 260814
URL: http://svnweb.freebsd.org/changeset/base/260814
Log:
Fix a possible memory use after free and leak situation associated
with USB device detach when using character device handles. This also
includes LibUSB. It turns out that "usb_close()" cannot always get a
reference to clean up its USB transfers and such, if called during the
kernel USB device detach.
Analysis by: hselasky @
Reported by: Juergen Lock <nox at jelal.kn-bremen.de>
MFC after: 1 week
Modified:
head/sys/dev/usb/usb_dev.c
head/sys/dev/usb/usb_device.c
Modified: head/sys/dev/usb/usb_dev.c
==============================================================================
--- head/sys/dev/usb/usb_dev.c Fri Jan 17 10:34:01 2014 (r260813)
+++ head/sys/dev/usb/usb_dev.c Fri Jan 17 10:35:18 2014 (r260814)
@@ -207,6 +207,11 @@ usb_ref_device(struct usb_cdev_privdata
DPRINTFN(2, "no device at %u\n", cpd->dev_index);
goto error;
}
+ if (cpd->udev->state == USB_STATE_DETACHED &&
+ (need_uref != 2)) {
+ DPRINTFN(2, "device is detached\n");
+ goto error;
+ }
if (cpd->udev->refcount == USB_DEV_REF_MAX) {
DPRINTFN(2, "no dev ref\n");
goto error;
@@ -922,23 +927,12 @@ usb_close(void *arg)
DPRINTFN(2, "cpd=%p\n", cpd);
- err = usb_ref_device(cpd, &refs, 0);
- if (err)
+ err = usb_ref_device(cpd, &refs,
+ 2 /* uref and allow detached state */);
+ if (err) {
+ DPRINTFN(0, "Cannot grab USB reference when "
+ "closing USB file handle\n");
goto done;
-
- /*
- * If this function is not called directly from the root HUB
- * thread, there is usually a need to lock the enumeration
- * lock. Check this.
- */
- if (!usbd_enum_is_locked(cpd->udev)) {
-
- DPRINTFN(2, "Locking enumeration\n");
-
- /* reference device */
- err = usb_usb_ref_device(cpd, &refs);
- if (err)
- goto done;
}
if (cpd->fflags & FREAD) {
usb_fifo_close(refs.rxfifo, cpd->fflags);
Modified: head/sys/dev/usb/usb_device.c
==============================================================================
--- head/sys/dev/usb/usb_device.c Fri Jan 17 10:34:01 2014 (r260813)
+++ head/sys/dev/usb/usb_device.c Fri Jan 17 10:35:18 2014 (r260814)
@@ -2070,6 +2070,8 @@ usb_free_device(struct usb_device *udev,
DPRINTFN(4, "udev=%p port=%d\n", udev, udev->port_no);
bus = udev->bus;
+
+ /* set DETACHED state to prevent any further references */
usb_set_device_state(udev, USB_STATE_DETACHED);
#if USB_HAVE_DEVCTL
@@ -2085,16 +2087,7 @@ usb_free_device(struct usb_device *udev,
usb_free_symlink(udev->ugen_symlink);
udev->ugen_symlink = NULL;
}
-#endif
- /*
- * Unregister our device first which will prevent any further
- * references:
- */
- usb_bus_port_set_device(bus, udev->parent_hub ?
- udev->parent_hub->hub->ports + udev->port_index : NULL,
- NULL, USB_ROOT_HUB_ADDR);
-#if USB_HAVE_UGEN
/* wait for all pending references to go away: */
mtx_lock(&usb_ref_lock);
udev->refcount--;
@@ -2114,6 +2107,11 @@ usb_free_device(struct usb_device *udev,
/* the following will get the device unconfigured in software */
usb_unconfigure(udev, USB_UNCFG_FLAG_FREE_EP0);
+ /* final device unregister after all character devices are closed */
+ usb_bus_port_set_device(bus, udev->parent_hub ?
+ udev->parent_hub->hub->ports + udev->port_index : NULL,
+ NULL, USB_ROOT_HUB_ADDR);
+
/* unsetup any leftover default USB transfers */
usbd_transfer_unsetup(udev->ctrl_xfer, USB_CTRL_XFER_MAX);
@@ -2647,8 +2645,14 @@ usb_set_device_state(struct usb_device *
DPRINTF("udev %p state %s -> %s\n", udev,
usb_statestr(udev->state), usb_statestr(state));
- udev->state = state;
+#if USB_HAVE_UGEN
+ mtx_lock(&usb_ref_lock);
+#endif
+ udev->state = state;
+#if USB_HAVE_UGEN
+ mtx_unlock(&usb_ref_lock);
+#endif
if (udev->bus->methods->device_state_change != NULL)
(udev->bus->methods->device_state_change) (udev);
}
More information about the svn-src-all
mailing list