linux/drivers/usb/class, branch v5.3

USB: cdc-wdm: fix race between write and disconnect due to flag abuse

2019-08-28T20:48:38Z

In case of a disconnect an ongoing flush() has to be made fail. Nevertheless we cannot be sure that any pending URB has already finished, so although they will never succeed, they still must not be touched. The clean solution for this is to check for WDM_IN_USE and WDM_DISCONNECTED in flush(). There is no point in ever clearing WDM_IN_USE, as no further writes make sense. The issue is as old as the driver. Fixes: afba937e540c9 ("USB: CDC WDM driver") Reported-by: syzbot+d232cca6ec42c2edb3fc@syzkaller.appspotmail.com Signed-off-by: Oliver Neukum Cc: stable Link: https://lore.kernel.org/r/20190827103436.21143-1-oneukum@suse.com Signed-off-by: Greg Kroah-Hartman

usbtmc: more sanity checking for packet size

2019-08-21T16:45:46Z

A malicious device can make the driver divide ny zero with a nonsense maximum packet size. Signed-off-by: Oliver Neukum Cc: stable Link: https://lore.kernel.org/r/20190820092826.17694-1-oneukum@suse.com Signed-off-by: Greg Kroah-Hartman

usb: cdc-acm: make sure a refcount is taken early enough

2019-08-15T12:49:16Z

destroy() will decrement the refcount on the interface, so that it needs to be taken so early that it never undercounts. Fixes: 7fb57a019f94e ("USB: cdc-acm: Fix potential deadlock (lockdep warning)") Cc: stable Reported-and-tested-by: syzbot+1b2449b7b5dc240d107a@syzkaller.appspotmail.com Signed-off-by: Oliver Neukum Link: https://lore.kernel.org/r/20190808142119.7998-1-oneukum@suse.com Signed-off-by: Greg Kroah-Hartman

docs: usb: rename files to .rst and add them to drivers-api

2019-06-20T12:28:36Z

While there are a mix of things here, most of the stuff were written from Kernel developer's PoV. So, add them to the driver-api book. A follow up for this patch would be to move documents from there that are specific to sysadmins, adding them to the admin-guide. Signed-off-by: Mauro Carvalho Chehab Acked-by: Johan Hovold Acked-by: Felipe Balbi Signed-off-by: Greg Kroah-Hartman

usb: cdc-wdm: remove redundant assignment to rv

2019-06-03T13:21:56Z

The variable rv is assigned with a value that is never read and it is re-assigned a new value on the next statement. The assignment is redundant and can be removed. Addresses-Coverity: ("Unused value") Signed-off-by: Colin Ian King Signed-off-by: Greg Kroah-Hartman

USB: cdc-acm: clean up throttle handling

2019-04-29T14:14:41Z

Clean up the throttle implementation by dropping the redundant throttle_req flag which was a remnant from back when USB serial had only a single read URB, something which was later carried over to cdc-acm. Also convert the throttled flag to an atomic bit flag. Signed-off-by: Johan Hovold Acked-by: Oliver Neukum Signed-off-by: Greg Kroah-Hartman

USB: cdc-acm: fix unthrottle races

2019-04-29T14:14:41Z

Fix two long-standing bugs which could potentially lead to memory corruption or leave the port throttled until it is reopened (on weakly ordered systems), respectively, when read-URB completion races with unthrottle(). First, the URB must not be marked as free before processing is complete to prevent it from being submitted by unthrottle() on another CPU. CPU 1 CPU 2 ================ ================ complete() unthrottle() process_urb(); smp_mb__before_atomic(); set_bit(i, free); if (test_and_clear_bit(i, free)) submit_urb(); Second, the URB must be marked as free before checking the throttled flag to prevent unthrottle() on another CPU from failing to observe that the URB needs to be submitted if complete() sees that the throttled flag is set. CPU 1 CPU 2 ================ ================ complete() unthrottle() set_bit(i, free); throttled = 0; smp_mb__after_atomic(); smp_mb(); if (throttled) if (test_and_clear_bit(i, free)) return; submit_urb(); Note that test_and_clear_bit() only implies barriers when the test is successful. To handle the case where the URB is still in use an explicit barrier needs to be added to unthrottle() for the second race condition. Also note that the first race was fixed by 36e59e0d70d6 ("cdc-acm: fix race between callback and unthrottle") back in 2015, but the bug was reintroduced a year later. Fixes: 1aba579f3cf5 ("cdc-acm: handle read pipe errors") Fixes: 088c64f81284 ("USB: cdc-acm: re-write read processing") Signed-off-by: Johan Hovold Acked-by: Oliver Neukum Cc: stable Signed-off-by: Greg Kroah-Hartman

usb: cdc-acm: fix race during wakeup blocking TX traffic

2019-03-27T15:08:49Z

When the kernel is compiled with preemption enabled, the URB completion handler can run in parallel with the work responsible for waking up the tty layer. If the URB handler sets the EVENT_TTY_WAKEUP bit during the call to tty_port_tty_wakeup() to signal that there is room for additional input, it will be cleared at the end of this call. As a result, TX traffic on the upper layer will be blocked. This can be seen with a kernel configured with CONFIG_PREEMPT, and a fast modem connected with PPP running over a USB CDC-ACM port. Use test_and_clear_bit() instead, which ensures that each wakeup requested by the URB completion code will trigger a call to tty_port_tty_wakeup(). Fixes: 1aba579f3cf5 cdc-acm: handle read pipe errors Signed-off-by: Romain Izard Cc: stable Acked-by: Oliver Neukum Signed-off-by: Greg Kroah-Hartman

cdc-wdm: pass return value of recover_from_urb_loss

2019-02-19T13:41:38Z

'rv' is the correct return value, pass it upstream instead of 0 Fixes: 17d80d562fd7 ("USB: autosuspend for cdc-wdm") Signed-off-by: YueHaibing Signed-off-by: Greg Kroah-Hartman

USB: add missing SPDX lines to Kconfig and Makefiles

2019-01-22T08:08:17Z

There are a few remaining drivers/usb/ files that do not have SPDX identifiers in them, all of these are either Kconfig or Makefiles. Add the correct GPL-2.0 identifier to them to make scanning tools happy. Signed-off-by: Greg Kroah-Hartman