mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-23 09:19:51 +00:00
![]() The new USBDEVFS_DROP_PRIVILEGES ioctl allows a process to voluntarily relinquish the ability to issue other ioctls that may interfere with other processes and drivers that have claimed an interface on the device. This commit also includes a simple utility to be able to test the ioctl, located at Documentation/usb/usbdevfs-drop-permissions.c Example (with qemu-kvm's input device): $ lsusb ... Bus 001 Device 002: ID 0627:0001 Adomax Technology Co., Ltd $ usb-devices ... C: #Ifs= 1 Cfg#= 1 Atr=a0 MxPwr=100mA I: If#= 0 Alt= 0 #EPs= 1 Cls=03(HID ) Sub=00 Prot=02 Driver=usbhid $ sudo ./usbdevfs-drop-permissions /dev/bus/usb/001/002 OK: privileges dropped! Available options: [0] Exit now [1] Reset device. Should fail if device is in use [2] Claim 4 interfaces. Should succeed where not in use [3] Narrow interface permission mask Which option shall I run?: 1 ERROR: USBDEVFS_RESET failed! (1 - Operation not permitted) Which test shall I run next?: 2 ERROR claiming if 0 (1 - Operation not permitted) ERROR claiming if 1 (1 - Operation not permitted) ERROR claiming if 2 (1 - Operation not permitted) ERROR claiming if 3 (1 - Operation not permitted) Which test shall I run next?: 0 After unbinding usbhid: $ usb-devices ... I: If#= 0 Alt= 0 #EPs= 1 Cls=03(HID ) Sub=00 Prot=02 Driver=(none) $ sudo ./usbdevfs-drop-permissions /dev/bus/usb/001/002 ... Which option shall I run?: 2 OK: claimed if 0 ERROR claiming if 1 (1 - Operation not permitted) ERROR claiming if 2 (1 - Operation not permitted) ERROR claiming if 3 (1 - Operation not permitted) Which test shall I run next?: 1 OK: USBDEVFS_RESET succeeded Which test shall I run next?: 0 After unbinding usbhid and restricting the mask: $ sudo ./usbdevfs-drop-permissions /dev/bus/usb/001/002 ... Which option shall I run?: 3 Insert new mask: 0 OK: privileges dropped! Which test shall I run next?: 2 ERROR claiming if 0 (1 - Operation not permitted) ERROR claiming if 1 (1 - Operation not permitted) ERROR claiming if 2 (1 - Operation not permitted) ERROR claiming if 3 (1 - Operation not permitted) Signed-off-by: Reilly Grant <reillyg@chromium.org> Acked-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Emilio López <emilio.lopez@collabora.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
||
---|---|---|
.. | ||
acm.txt | ||
anchors.txt | ||
authorization.txt | ||
bulk-streams.txt | ||
callbacks.txt | ||
chipidea.txt | ||
CREDITS | ||
dma.txt | ||
dwc3.txt | ||
ehci.txt | ||
error-codes.txt | ||
functionfs.txt | ||
gadget-testing.txt | ||
gadget_configfs.txt | ||
gadget_hid.txt | ||
gadget_multi.txt | ||
gadget_printer.txt | ||
gadget_serial.txt | ||
hotplug.txt | ||
iuu_phoenix.txt | ||
linux-cdc-acm.inf | ||
linux.inf | ||
mass-storage.txt | ||
misc_usbsevseg.txt | ||
mtouchusb.txt | ||
ohci.txt | ||
persist.txt | ||
power-management.txt | ||
proc_usb_info.txt | ||
rio.txt | ||
URB.txt | ||
usb-help.txt | ||
usb-serial.txt | ||
usbdevfs-drop-permissions.c | ||
usbip_protocol.txt | ||
usbmon.txt | ||
wusb-cbaf | ||
WUSB-Design-overview.txt |