Drop the redundant interrupt-in-running flag, which tried to keep track
of when the interrupt-in URB was in flight. This isn't needed since we
can stop the URB unconditionally in tower_abort_transfers() and the URB
can not be submitted while usb_kill_urb() is running anyway.
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20191105084152.16322-7-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Since commit d4ead16f50 ("USB: prevent char device open/deregister
race") core prevents further calls to open() after usb_deregister_dev()
returns so there's no need to use the interface data for
synchronisation.
This effectively reverts commit 54d2bc068f ("USB: fix locking in
idmouse") with respect to the open-disconnect race.
Note that the driver already uses a present flag to suppress I/O post
disconnect (even if all USB I/O take place at open).
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20191105103638.4929-2-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
A recent info-leak bug manifested itself along with warning about a
negative buffer overflow:
ldusb 1-1:0.28: Read buffer overflow, -131383859965943 bytes dropped
when it was really a rather large positive one.
A sanity check that prevents this has now been put in place, but let's
fix up the size format specifiers, which should all be unsigned.
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20191022143203.5260-3-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The custom ring-buffer implementation was merged without any locking or
explicit memory barriers, but a spinlock was later added by commit
9d33efd9a7 ("USB: ldusb bugfix").
The lock did not cover the update of the tail index once the entry had
been processed, something which could lead to memory corruption on
weakly ordered architectures or due to compiler optimisations.
Specifically, a completion handler running on another CPU might observe
the incremented tail index and update the entry before ld_usb_read() is
done with it.
Fixes: 2824bd250f ("[PATCH] USB: add ldusb driver")
Fixes: 9d33efd9a7 ("USB: ldusb bugfix")
Cc: stable <stable@vger.kernel.org> # 2.6.13
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20191022143203.5260-2-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fix broken read implementation, which could be used to trigger slab info
leaks.
The driver failed to check if the custom ring buffer was still empty
when waking up after having waited for more data. This would happen on
every interrupt-in completion, even if no data had been added to the
ring buffer (e.g. on disconnect events).
Due to missing sanity checks and uninitialised (kmalloced) ring-buffer
entries, this meant that huge slab info leaks could easily be triggered.
Note that the empty-buffer check after wakeup is enough to fix the info
leak on disconnect, but let's clear the buffer on allocation and add a
sanity check to read() to prevent further leaks.
Fixes: 2824bd250f ("[PATCH] USB: add ldusb driver")
Cc: stable <stable@vger.kernel.org> # 2.6.13
Reported-by: syzbot+6fe95b826644f7f12b0b@syzkaller.appspotmail.com
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20191018151955.25135-2-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The driver was using its struct usb_interface pointer as an inverted
disconnected flag, but was setting it to NULL without making sure all
code paths that used it were done with it.
Before commit ef61eb43ad ("USB: yurex: Fix protection fault after
device removal") this included the interrupt-in completion handler, but
there are further accesses in dev_err and dev_dbg statements in
yurex_write() and the driver-data destructor (sic!).
Fix this by unconditionally stopping also the control URB at disconnect
and by using a dedicated disconnected flag.
Note that we need to take a reference to the struct usb_interface to
avoid a use-after-free in the destructor whenever the device was
disconnected while the character device was still open.
Fixes: aadd6472d9 ("USB: yurex.c: remove dbg() usage")
Fixes: 45714104b9 ("USB: yurex.c: remove err() usage")
Cc: stable <stable@vger.kernel.org> # 3.5: ef61eb43ad
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20191009153848.8664-6-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Drop the redundant disconnect mutex which was introduced after the
open-disconnect race had been addressed generally in USB core by commit
d4ead16f50 ("USB: prevent char device open/deregister race").
Specifically, the rw-semaphore in core guarantees that all calls to
open() will have completed and that no new calls to open() will occur
after usb_deregister_dev() returns. Hence there is no need use the
driver data as an inverted disconnected flag.
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20191009104846.5925-5-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
A recent fix addressing a deadlock on disconnect introduced a new bug
by moving the present flag out of the critical section protected by the
driver-data mutex. This could lead to a racing release() freeing the
driver data before disconnect() is done with it.
Due to insufficient locking a related use-after-free could be triggered
also before the above mentioned commit. Specifically, the driver needs
to hold the driver-data mutex also while checking the opened flag at
disconnect().
Fixes: c468a8aa79 ("usb: iowarrior: fix deadlock on disconnect")
Fixes: 946b960d13 ("USB: add driver for iowarrior devices.")
Cc: stable <stable@vger.kernel.org> # 2.6.21
Reported-by: syzbot+0761012cebf7bdb38137@syzkaller.appspotmail.com
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20191009104846.5925-2-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The driver was using its struct usb_interface pointer as an inverted
disconnected flag, but was setting it to NULL before making sure all
completion handlers had run. This could lead to a NULL-pointer
dereference in a number of dev_dbg, dev_warn and dev_err statements in
the completion handlers which relies on said pointer.
Fix this by unconditionally stopping all I/O and preventing
resubmissions by poisoning the interrupt URBs at disconnect and using a
dedicated disconnected flag.
This also makes sure that all I/O has completed by the time the
disconnect callback returns.
Fixes: 2824bd250f ("[PATCH] USB: add ldusb driver")
Cc: stable <stable@vger.kernel.org> # 2.6.13
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20191009153848.8664-4-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Currently the driver don't support pm_ops. These ops are not necessary
if the supply isn't switchable (always on). This assumptions seems to be
wrong because no one needs a powered hub during suspend-to-ram/disk.
So adding simple_dev_pm_ops to be able to switch off the hub during
suspend and to restore the config after a resume operation.
Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
Acked-by: Richard Leitner <richard.leitner@skidata.com>
Link: https://lore.kernel.org/r/20190917144449.32739-5-m.felsch@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The driver is using its struct usb_device pointer as an inverted
disconnected flag, but was setting it to NULL before making sure all
completion handlers had run. This could lead to a NULL-pointer
dereference in a number of dev_dbg and dev_err statements in the
completion handlers which relies on said pointer.
Fix this by unconditionally stopping all I/O and preventing
resubmissions by poisoning the interrupt URBs at disconnect and using a
dedicated disconnected flag.
This also makes sure that all I/O has completed by the time the
disconnect callback returns.
Fixes: 9d974b2a06 ("USB: legousbtower.c: remove err() usage")
Fixes: fef526cae7 ("USB: legousbtower: remove custom debug macro")
Fixes: 4dae996380 ("USB: legotower: remove custom debug macro and module parameter")
Cc: stable <stable@vger.kernel.org> # 3.5
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20190919083039.30898-4-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Drop the redundant disconnect mutex which was introduced after the
open-disconnect race had been addressed generally in USB core by commit
d4ead16f50 ("USB: prevent char device open/deregister race").
Specifically, the rw-semaphore in core guarantees that all calls to
open() will have completed and that no new calls to open() will occur
after usb_deregister_dev() returns. Hence there is no need use the
driver data as an inverted disconnected flag.
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20190926091228.24634-8-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
According to Greg KH, it has been generally agreed that when a USB
driver encounters an unknown error (or one it can't handle directly),
it should just give up instead of going into a potentially infinite
retry loop.
The three codes -EPROTO, -EILSEQ, and -ETIME fall into this category.
They can be caused by bus errors such as packet loss or corruption,
attempting to communicate with a disconnected device, or by malicious
firmware. Nowadays the extent of packet loss or corruption is
negligible, so it should be safe for a driver to give up whenever one
of these errors occurs.
Although the yurex driver handles -EILSEQ errors in this way, it
doesn't do the same for -EPROTO (as discovered by the syzbot fuzzer)
or other unrecognized errors. This patch adjusts the driver so that
it doesn't log an error message for -EPROTO or -ETIME, and it doesn't
retry after any errors.
Reported-and-tested-by: syzbot+b24d736f18a1541ad550@syzkaller.appspotmail.com
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
CC: Tomoki Sekiyama <tomoki.sekiyama@gmail.com>
CC: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/Pine.LNX.4.44L0.1909171245410.1590-100000@iolanthe.rowland.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The driver was using its struct usb_device pointer as an inverted
disconnected flag, but was setting it to NULL before making sure all
completion handlers had run. This could lead to a NULL-pointer
dereference in a number of dev_dbg statements in the completion handlers
which relies on said pointer.
The pointer was also dereferenced unconditionally in a dev_dbg statement
release() something which would lead to a NULL-deref whenever a device
was disconnected before the final character-device close if debugging
was enabled.
Fix this by unconditionally stopping all I/O and preventing
resubmissions by poisoning the interrupt URBs at disconnect and using a
dedicated disconnected flag.
This also makes sure that all I/O has completed by the time the
disconnect callback returns.
Fixes: 1ef37c6047 ("USB: adutux: remove custom debug macro and module parameter")
Fixes: 66d4bc30d1 ("USB: adutux: remove custom debug macro")
Cc: stable <stable@vger.kernel.org> # 3.12
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20190925092913.8608-2-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The syzbot fuzzer found a lockdep violation in the rio500 driver:
======================================================
WARNING: possible circular locking dependency detected
5.3.0-rc2+ #23 Not tainted
------------------------------------------------------
syz-executor.2/20386 is trying to acquire lock:
00000000772249c6 (rio500_mutex){+.+.}, at: open_rio+0x16/0xc0
drivers/usb/misc/rio500.c:64
but task is already holding lock:
00000000d3e8f4b9 (minor_rwsem){++++}, at: usb_open+0x23/0x270
drivers/usb/core/file.c:39
which lock already depends on the new lock.
The problem is that the driver's open_rio() routine is called while
the usbcore's minor_rwsem is locked for reading, and it acquires the
rio500_mutex; whereas conversely, probe_rio() and disconnect_rio()
first acquire the rio500_mutex and then call usb_register_dev() or
usb_deregister_dev(), which lock minor_rwsem for writing.
The correct ordering of acquisition should be: minor_rwsem first, then
rio500_mutex (since the locking in open_rio() cannot be changed).
Thus, the probe and disconnect routines should avoid holding
rio500_mutex while doing their registration and deregistration.
This patch adjusts the code in those two routines to do just that. It
also relies on the fact that the probe and disconnect routines are
protected by the device mutex, so the initial test of rio->present
needs no extra locking.
Reported-by: syzbot+7bbcbe9c9ff0cd49592a@syzkaller.appspotmail.com
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Fixes: d710734b06 ("USB: rio500: simplify locking")
Acked-by: Oliver Neukum <oneukum@suse.com>
CC: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/Pine.LNX.4.44L0.1908081329240.1319-100000@iolanthe.rowland.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
