The driver will forward errors to userspace after turning most of them
into -EIO. But all status codes are not equal. The -EPIPE (stall) in
particular can be seen more as a result of normal USB signaling than
an actual error. The state is automatically cleared by the USB core
without intervention from either driver or userspace.
And most devices and firmwares will never trigger a stall as a result
of GetEncapsulatedResponse. This is in fact a requirement for CDC WDM
devices. Quoting from section 7.1 of the CDC WMC spec revision 1.1:
The function shall not return STALL in response to
GetEncapsulatedResponse.
But this driver is also handling GetEncapsulatedResponse on behalf of
the qmi_wwan and cdc_mbim drivers. Unfortunately the relevant specs
are not as clear wrt stall. So some QMI and MBIM devices *will*
occasionally stall, causing the GetEncapsulatedResponse to return an
-EPIPE status. Translating this into -EIO for userspace has proven to
be harmful. Treating it as an empty read is safer, making the driver
behave as if the device was conforming to the CDC WDM spec.
There have been numerous reports of issues related to -EPIPE errors
from some newer CDC MBIM devices in particular, like for example the
Fibocom L831-EAU. Testing on this device has shown that the issues
go away if we simply ignore the -EPIPE status. Similar handling of
-EPIPE is already known from e.g. usb_get_string()
The -EPIPE log message is still kept to let us track devices with this
unexpected behaviour, hoping that it attracts attention from firmware
developers.
Cc: <stable@vger.kernel.org>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=100938
Reported-and-tested-by: Christian Ehrig <christian.ehrig@mediamarktsaturn-bt.com>
Reported-and-tested-by: Patrick Chilton <chpatrick@gmail.com>
Reported-and-tested-by: Andreas Böhler <news@aboehler.at>
Signed-off-by: Bjørn Mork <bjorn@mork.no>
Acked-by: Oliver Neukum <oneukum@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
attribute_group are not supposed to change at runtime. All functions
working with attribute_group provided by <linux/sysfs.h> work with
const attribute_group. So mark the non-const structs as const.
Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This reverts commit 833415a3e7 ("cdc-wdm: fix "out-of-sync" due to
missing notifications")
There have been several reports of wdm_read returning unexpected EIO
errors with QMI devices using the qmi_wwan driver. The reporters
confirm that reverting prevents these errors. I have been unable to
reproduce the bug myself, and have no explanation to offer either. But
reverting is the safe choice here, given that the commit was an
attempt to work around a firmware problem. Living with a firmware
problem is still better than adding driver bugs.
Reported-by: Kasper Holtze <kasper@holtze.dk>
Reported-by: Aleksander Morgado <aleksander@aleksander.es>
Reported-by: Daniele Palmas <dnlplm@gmail.com>
Cc: <stable@vger.kernel.org> # v4.9+
Fixes: 833415a3e7 ("cdc-wdm: fix "out-of-sync" due to missing notifications")
Signed-off-by: Bjørn Mork <bjorn@mork.no>
Acked-by: Oliver Neukum <oneukum@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
write_used was introduced with commit 884b600f63 ("[PATCH] USB: fix acm
trouble with terminals") but never used since.
Signed-off-by: Tobias Herzog <t-herzog@gmx.de>
Acked-by: Oliver Neukum <oneukum@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Adds a similar log message to USB_CDC_NOTIFY_SERIAL_STATE as it is
already done with USB_CDC_NOTIFY_NETWORK_CONNECTION.
Signed-off-by: Tobias Herzog <t-herzog@gmx.de>
Acked-by: Oliver Neukum <oneukum@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
USB devices may have very limited endpoint packet sizes, so that
notifications can not be transferred within one single usb packet.
Reassembling of multiple packages may be necessary.
Signed-off-by: Tobias Herzog <t-herzog@gmx.de>
Acked-by: Oliver Neukum <oneukum@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Notifications may only be 8 bytes long. Accessing the 9th and
10th byte of unimplemented/unknown notifications may be insecure.
Also check the length of known notifications before accessing anything
behind the 8th byte.
Signed-off-by: Tobias Herzog <t-herzog@gmx.de>
Acked-by: Oliver Neukum <oneukum@suse.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Use the new endpoint helpers to lookup the required bulk-in and bulk-out
endpoints, and the optional interrupt-in endpoint.
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This resolves a merge issue in the gadget code, and we want the USB
fixes in here as well.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Use the new endpoint helpers to lookup the required bulk-out endpoint
and the depending on protocol likewise required bulk-in endpoint.
Cc: Pete Zaitcev <zaitcev@redhat.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Use the new endpoint helpers to lookup the required bulk-in, bulk-out
and interrupt-in endpoints for collapsed interfaces.
Note that there is already a check verifying that there are exactly
three endpoints so we'd still be bailing out if there's an unexpected
endpoint type.
Cc: Oliver Neukum <oneukum@suse.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Make sure to initialise the return value to avoid having allocation
failures going unnoticed when allocating interrupt-endpoint resources.
This prevents use-after-free or worse when the device is later unbound.
Fixes: dbf3e7f654 ("Implement an ioctl to support the USMTMC-USB488 READ_STATUS_BYTE operation.")
Cc: stable <stable@vger.kernel.org> # 4.6
Cc: Dave Penkler <dpenkler@gmail.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
USBTMC devices are required to have a bulk-in and a bulk-out endpoint,
but the driver failed to verify this, something which could lead to the
endpoint addresses being taken from uninitialised memory.
Make sure to zero all private data as part of allocation, and add the
missing endpoint sanity check.
Note that this also addresses a more recently introduced issue, where
the interrupt-in-presence flag would also be uninitialised whenever the
optional interrupt-in endpoint is not present. This in turn could lead
to an interrupt urb being allocated, initialised and submitted based on
uninitialised values.
Fixes: dbf3e7f654 ("Implement an ioctl to support the USMTMC-USB488 READ_STATUS_BYTE operation.")
Fixes: 5b775f672c ("USB: add USB test and measurement class driver")
Cc: stable <stable@vger.kernel.org> # 2.6.28
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Remove logically dead code.
'cntr' is always equal to zero when the following line of code is executed:
rv = cntr ? cntr : -EAGAIN;
Addresses-Coverity-ID: 113227
Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
Acked-by: Oliver Neukum <oneukum@suse.com>
Reviewed-by: Peter Senna Tschudin <peter.senna@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The driver reports that it always uses a low-latency mode by returning
the ASYNC_LOW_LATENCY flag through TIOCGSERIAL.
Even if this behaviour could not be changed, this may have made some
sense prior to 7a9a65ced1 ("cdc-acm: Fix long standing abuse of
tty->low_latency") which removed the unconditional setting of the
corresponding tty low_latency flag (something which had always been
broken in itself).
Since the driver does not have a low-latency mode, let's drop the flag.
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Read urbs are submitted back only on success, causing read pipe
running out of urbs after few errors. No more characters can
be read from tty device then until it is reopened and no errors
are reported.
Fix that by always submitting urbs back and clearing stall on
-EPIPE.
Signed-off-by: Ladislav Michl <ladis@linux-mips.org>
Acked-by: Oliver Neukum <oneukum@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
