kernel/linux.git/drivers/usb/class, branch v4.19.77

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

2019-09-06T08:22:14+00:00

commit 1426bd2c9f7e3126e2678e7469dca9fd9fc6dd3e upstream. 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

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

2019-08-25T08:48:00+00:00

commit c52873e5a1ef72f845526d9f6a50704433f9c625 upstream. 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

USB: cdc-acm: fix unthrottle races

2019-05-10T15:54:10+00:00

commit 764478f41130f1b8d8057575b89e69980a0f600d upstream. 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 Signed-off-by: Greg Kroah-Hartman

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

2019-04-03T04:26:28+00:00

commit 93e1c8a638308980309e009cc40b5a57ef87caf1 upstream. 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

usb: cdc-acm: send ZLP for Telit 3G Intel based modems

2019-01-16T21:04:31+00:00

commit 34aabf918717dd14e05051896aaecd3b16b53d95 upstream. Telit 3G Intel based modems require zero packet to be sent if out data size is equal to the endpoint max packet size. Signed-off-by: Daniele Palmas Cc: stable Signed-off-by: Greg Kroah-Hartman

cdc-acm: fix abnormal DATA RX issue for Mediatek Preloader.

2019-01-09T16:38:45+00:00

commit eafb27fa5283599ce6c5492ea18cf636a28222bb upstream. Mediatek Preloader is a proprietary embedded boot loader for loading Little Kernel and Linux into device DRAM. This boot loader also handle firmware update. Mediatek Preloader will be enumerated as a virtual COM port when the device is connected to Windows or Linux OS via CDC-ACM class driver. When the USB enumeration has been done, Mediatek Preloader will send out handshake command "READY" to PC actively instead of waiting command from the download tool. Since Linux 4.12, the commit "tty: reset termios state on device registration" (93857edd9829e144acb6c7e72d593f6e01aead66) causes Mediatek Preloader receiving some abnoraml command like "READYXX" as it sent. This will be recognized as an incorrect response. The behavior change also causes the download handshake fail. This change only affects subsequent connects if the reconnected device happens to get the same minor number. By disabling the ECHO termios flag could avoid this problem. However, it cannot be done by user space configuration when download tool open /dev/ttyACM0. This is because the device running Mediatek Preloader will send handshake command "READY" immediately once the CDC-ACM driver is ready. This patch wants to fix above problem by introducing "DISABLE_ECHO" property in driver_info. When Mediatek Preloader is connected, the CDC-ACM driver could disable ECHO flag in termios to avoid the problem. Signed-off-by: Macpaul Lin Cc: stable@vger.kernel.org Reviewed-by: Johan Hovold Acked-by: Oliver Neukum Signed-off-by: Greg Kroah-Hartman

usb: cdc-acm: add entry for Hiro (Conexant) modem

2018-11-27T15:13:09+00:00

commit 63529eaa6164ef7ab4b907b25ac3648177e5e78f upstream. The cdc-acm kernel module currently does not support the Hiro (Conexant) H05228 USB modem. The patch below adds the device specific information: idVendor 0x0572 idProduct 0x1349 Signed-off-by: Maarten Jacobs Acked-by: Oliver Neukum Cc: stable Signed-off-by: Greg Kroah-Hartman

cdc-acm: correct counting of UART states in serial state notification

2018-10-09T14:13:42+00:00

The usb standard ("Universal Serial Bus Class Definitions for Communication Devices") distiguishes between "consistent signals" (DSR, DCD), and "irregular signals" (break, ring, parity error, framing error, overrun). The bits of "irregular signals" are set, if this error/event occurred on the device side and are immeadeatly unset, if the serial state notification was sent. Like other drivers of real serial ports do, just the occurence of those events should be counted in serial_icounter_struct (but no 1->0 transitions). Signed-off-by: Tobias Herzog Acked-by: Oliver Neukum Cc: stable Signed-off-by: Greg Kroah-Hartman

cdc-acm: do not reset notification buffer index upon urb unlinking

2018-10-09T14:13:42+00:00

Resetting the write index of the notification buffer on urb unlink (e.g. closing a cdc-acm device from userspace) may lead to wrong interpretation of further received notifications, in case the index is not 0 when urb unlink happens (i.e. when parts of a notification already have been transferred). On the device side there is no "reset" of the notification transimission and thus we would get out of sync with the device. Signed-off-by: Tobias Herzog Acked-by: Oliver Neukum Cc: stable Signed-off-by: Greg Kroah-Hartman

cdc-acm: fix race between reset and control messaging

2018-10-09T14:13:42+00:00

If a device splits up a control message and a reset() happens between the parts, the message is lost and already recieved parts must be dropped. Signed-off-by: Oliver Neukum Fixes: 1aba579f3cf51 ("cdc-acm: handle read pipe errors") Cc: stable Signed-off-by: Greg Kroah-Hartman