commit 73ea73affe8622bdf292de898da869d441da6a9d upstream.
The KOBJ_CHANGE uevent is sent before gadget unbind is actually
executed, resulting in inaccurate uevent emitted at incorrect timing
(the uevent would have USB_UDC_DRIVER variable set while it would
soon be removed).
Move the KOBJ_CHANGE uevent to the end of the unbind function so that
uevent is sent only after the change has been made.
Fixes: 2ccea03a8f ("usb: gadget: introduce UDC Class")
Cc: stable@vger.kernel.org
Signed-off-by: Roy Luo <royluo@google.com>
Link: https://lore.kernel.org/r/20231128221756.2591158-1-royluo@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 61890dc28f7d9e9aac8a9471302613824c22fae4 upstream.
The commit 89ff3dfac6 ("usb: gadget: f_hid: fix f_hidg lifetime vs
cdev") has introduced a bug that leads to hid device corruption after
the replug operation.
Reverse device managed memory allocation for the report descriptor
to fix the issue.
Tested:
This change was tested on the AMD EthanolX CRB server with the BMC
based on the OpenBMC distribution. The BMC provides KVM functionality
via the USB gadget device:
- before: KVM page refresh results in a broken USB device,
- after: KVM page refresh works without any issues.
Fixes: 89ff3dfac6 ("usb: gadget: f_hid: fix f_hidg lifetime vs cdev")
Cc: stable@vger.kernel.org
Signed-off-by: Konstantin Aladyshev <aladyshev22@gmail.com>
Link: https://lore.kernel.org/r/20231206080744.253-2-aladyshev22@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit a04224da1f3424b2c607b12a3bd1f0e302fb8231 ]
Previously, gadget assignment to the net device occurred exclusively
during the initial binding attempt.
Nevertheless, the gadget pointer could change during bind/unbind
cycles due to various conditions, including the unloading/loading
of the UDC device driver or the detachment/reconnection of an
OTG-capable USB hub device.
This patch relocates the gether_set_gadget() function out from
ncm_opts->bound condition check, ensuring that the correct gadget
is assigned during each bind request.
The provided logs demonstrate the consistency of ncm_opts throughout
the power cycle, while the gadget may change.
* OTG hub connected during boot up and assignment of gadget and
ncm_opts pointer
[ 2.366301] usb 2-1.5: New USB device found, idVendor=2996, idProduct=0105
[ 2.366304] usb 2-1.5: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[ 2.366306] usb 2-1.5: Product: H2H Bridge
[ 2.366308] usb 2-1.5: Manufacturer: Aptiv
[ 2.366309] usb 2-1.5: SerialNumber: 13FEB2021
[ 2.427989] usb 2-1.5: New USB device found, VID=2996, PID=0105
[ 2.428959] dabridge 2-1.5:1.0: dabridge 2-4 total endpoints=5, 0000000093a8d681
[ 2.429710] dabridge 2-1.5:1.0: P(0105) D(22.06.22) F(17.3.16) H(1.1) high-speed
[ 2.429714] dabridge 2-1.5:1.0: Hub 2-2 P(0151) V(06.87)
[ 2.429956] dabridge 2-1.5:1.0: All downstream ports in host mode
[ 2.430093] gadget 000000003c414d59 ------> gadget pointer
* NCM opts and associated gadget pointer during First ncm_bind
[ 34.763929] NCM opts 00000000aa304ac9
[ 34.763930] NCM gadget 000000003c414d59
* OTG capable hub disconnecte or assume driver unload.
[ 97.203114] usb 2-1: USB disconnect, device number 2
[ 97.203118] usb 2-1.1: USB disconnect, device number 3
[ 97.209217] usb 2-1.5: USB disconnect, device number 4
[ 97.230990] dabr_udc deleted
* Reconnect the OTG hub or load driver assaign new gadget pointer.
[ 111.534035] usb 2-1.1: New USB device found, idVendor=2996, idProduct=0120, bcdDevice= 6.87
[ 111.534038] usb 2-1.1: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[ 111.534040] usb 2-1.1: Product: Vendor
[ 111.534041] usb 2-1.1: Manufacturer: Aptiv
[ 111.534042] usb 2-1.1: SerialNumber: Superior
[ 111.535175] usb 2-1.1: New USB device found, VID=2996, PID=0120
[ 111.610995] usb 2-1.5: new high-speed USB device number 8 using xhci-hcd
[ 111.630052] usb 2-1.5: New USB device found, idVendor=2996, idProduct=0105, bcdDevice=21.02
[ 111.630055] usb 2-1.5: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[ 111.630057] usb 2-1.5: Product: H2H Bridge
[ 111.630058] usb 2-1.5: Manufacturer: Aptiv
[ 111.630059] usb 2-1.5: SerialNumber: 13FEB2021
[ 111.687464] usb 2-1.5: New USB device found, VID=2996, PID=0105
[ 111.690375] dabridge 2-1.5:1.0: dabridge 2-8 total endpoints=5, 000000000d87c961
[ 111.691172] dabridge 2-1.5:1.0: P(0105) D(22.06.22) F(17.3.16) H(1.1) high-speed
[ 111.691176] dabridge 2-1.5:1.0: Hub 2-6 P(0151) V(06.87)
[ 111.691646] dabridge 2-1.5:1.0: All downstream ports in host mode
[ 111.692298] gadget 00000000dc72f7a9 --------> new gadget ptr on connect
* NCM opts and associated gadget pointer during second ncm_bind
[ 113.271786] NCM opts 00000000aa304ac9 -----> same opts ptr used during first bind
[ 113.271788] NCM gadget 00000000dc72f7a9 ----> however new gaget ptr, that will not set
in net_device due to ncm_opts->bound = true
Signed-off-by: Hardik Gajjar <hgajjar@de.adit-jv.com>
Link: https://lore.kernel.org/r/20231020153324.82794-1-hgajjar@de.adit-jv.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit e8033bde451eddfb9b1bbd6e2d848c1b5c277222 upstream.
Currently, if a USB request that was queued by Raw Gadget is interrupted
(via a signal), wait_for_completion_interruptible returns -ERESTARTSYS.
Raw Gadget then attempts to propagate this value to userspace as a return
value from its ioctls. However, when -ERESTARTSYS is returned by a syscall
handler, the kernel internally restarts the syscall.
This doesn't allow userspace applications to interrupt requests queued by
Raw Gadget (which is required when the emulated device is asked to switch
altsettings). It also violates the implied interface of Raw Gadget that a
single ioctl must only queue a single USB request.
Instead, make Raw Gadget do what GadgetFS does: check whether the request
was interrupted (dequeued with status == -ECONNRESET) and report -EINTR to
userspace.
Fixes: f2c2e71764 ("usb: gadget: add raw-gadget interface")
Cc: stable <stable@kernel.org>
Signed-off-by: Andrey Konovalov <andreyknvl@gmail.com>
Link: https://lore.kernel.org/r/0db45b1d7cc466e3d4d1ab353f61d63c977fbbc5.1698350424.git.andreyknvl@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 427694cfaa upstream.
When NCM is used with hosts like Windows PC, it is observed that there are
multiple NTB's contained in one usb request giveback. Since the driver
unwraps the obtained request data assuming only one NTB is present, we
loose the subsequent NTB's present resulting in data loss.
Fix this by checking the parsed block length with the obtained data
length in usb request and continue parsing after the last byte of current
NTB.
Cc: stable@vger.kernel.org
Fixes: 9f6ce4240a ("usb: gadget: f_ncm.c added")
Signed-off-by: Krishna Kurapati <quic_kriskura@quicinc.com>
Reviewed-by: Maciej Żenczykowski <maze@google.com>
Link: https://lore.kernel.org/r/20230927105858.12950-1-quic_kriskura@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit ce9daa2efc ]
We should verify the bound of the array to assure that host
may not manipulate the index to point past endpoint array.
Signed-off-by: Ma Ke <make_ruc2021@163.com>
Acked-by: Li Yang <leoyang.li@nxp.com>
Link: https://lore.kernel.org/r/20230628081511.186850-1-make_ruc2021@163.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 55c3e571d2 ]
Fix a "variable set but not used" warning in f_mass_storage.c. rc is
used if verbose debugging is enabled but not otherwise.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Fixes: d5e2b67aae ("USB: g_mass_storage: template f_mass_storage.c file created")
Link: https://lore.kernel.org/r/cfed16c7-aa46-494b-ba84-b0e0dc99be3a@rowland.harvard.edu
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit e599046994 ]
When serial console over USB is enabled, gs_console_connect
queues gs_console_work, where it acquires the spinlock and
queues the usb request, and this request goes to gadget layer.
Now consider a situation where gadget layer prints something
to dmesg, this will eventually call gs_console_write() which
requires cons->lock. And this causes spinlock recursion. Avoid
this by excluding usb_ep_queue from the spinlock.
spin_lock_irqsave //needs cons->lock
gs_console_write
.
.
_printk
__warn_printk
dev_warn/pr_err
.
.
[USB Gadget Layer]
.
.
usb_ep_queue
gs_console_work
__gs_console_push // acquires cons->lock
process_one_work
Signed-off-by: Prashanth K <quic_prashk@quicinc.com>
Link: https://lore.kernel.org/r/1683638872-6885-1-git-send-email-quic_prashk@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit f4fc01af5b upstream.
The legacy gadget driver omitted calling usb_gadget_check_config()
to ensure that the USB device controller (UDC) has adequate resources,
including sufficient endpoint numbers and types, to support the given
configuration.
Previously, usb_add_config() was solely invoked by the legacy gadget
driver. Adds the necessary usb_gadget_check_config() after the bind()
operation to fix the issue.
Fixes: dce49449e0 ("usb: cdns3: allocate TX FIFO size according to composite EP number")
Cc: stable <stable@kernel.org>
Reported-by: Ravi Gunasekaran <r-gunasekaran@ti.com>
Signed-off-by: Frank Li <Frank.Li@nxp.com>
Link: https://lore.kernel.org/r/20230707230015.494999-1-Frank.Li@nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit a8291be6b5 upstream.
This reverts commit f08aa7c80d.
The reverted commit was based on static analysis and a misunderstanding
of how PTR_ERR() and NULLs are supposed to work. When a function
returns both pointer errors and NULL then normally the NULL means
"continue operating without a feature because it was deliberately
turned off". The NULL should not be treated as a failure. If a driver
cannot work when that feature is disabled then the KConfig should
enforce that the function cannot return NULL. We should not need to
test for it.
In this driver, the bug means that probe cannot succeed when CONFIG_PM
is disabled.
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Fixes: f08aa7c80d ("usb: gadget: tegra-xudc: Fix error check in tegra_xudc_powerdomain_init()")
Cc: stable <stable@kernel.org>
Link: https://lore.kernel.org/r/ZKQoBa84U/ykEh3C@moroto
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 2f6ecb89fe ]
Consider a case where gserial_disconnect has already cleared
gser->ioport. And if gserial_suspend gets called afterwards,
it will lead to accessing of gser->ioport and thus causing
null pointer dereference.
Avoid this by adding a null pointer check. Added a static
spinlock to prevent gser->ioport from becoming null after
the newly added null pointer check.
Fixes: aba3a8d01d ("usb: gadget: u_serial: add suspend resume callbacks")
Signed-off-by: Prashanth K <quic_prashk@quicinc.com>
Link: https://lore.kernel.org/r/1683278317-11774-1-git-send-email-quic_prashk@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 016da9c65f ]
The "udc" pointer was never set in the probe() function so it will
lead to a NULL dereference in udc_pci_remove() when we do:
usb_del_gadget_udc(&udc->gadget);
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Link: https://lore.kernel.org/r/ZG+A/dNpFWAlCChk@kili
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit efb6b53520 upstream.
While exercising the unbind path, with the current implementation
the functionfs_unbind would be calling which waits for the ffs->mutex
to be available, however within the same time ffs_ep0_read is invoked
& if no setup packets are pending, it will invoke function
wait_event_interruptible_exclusive_locked_irq which by definition waits
for the ev.count to be increased inside the same mutex for which
functionfs_unbind is waiting.
This creates deadlock situation because the functionfs_unbind won't
get the lock until ev.count is increased which can only happen if
the caller ffs_func_unbind can proceed further.
Following is the illustration:
CPU1 CPU2
ffs_func_unbind() ffs_ep0_read()
mutex_lock(ffs->mutex)
wait_event(ffs->ev.count)
functionfs_unbind()
mutex_lock(ffs->mutex)
mutex_unlock(ffs->mutex)
ffs_event_add()
<deadlock>
Fix this by moving the event unbind before functionfs_unbind
to ensure the ev.count is incrased properly.
Fixes: 6a19da1110 ("usb: gadget: f_fs: Prevent race during ffs_ep0_queue_wait")
Cc: stable <stable@kernel.org>
Signed-off-by: Uttkarsh Aggarwal <quic_uaggarwa@quicinc.com>
Link: https://lore.kernel.org/r/20230525092854.7992-1-quic_uaggarwa@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit b93c2a68f3 ]
The wakeup bit in the bmAttributes field indicates whether the device
is configured for remote wakeup. But this field should be allowed to
set only if the UDC supports such wakeup mechanism. So configure this
field based on UDC capability. Also inform the UDC whether the device
is configured for remote wakeup by implementing a gadget op.
Reviewed-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
Signed-off-by: Elson Roy Serrao <quic_eserrao@quicinc.com>
Link: https://lore.kernel.org/r/1679694482-16430-2-git-send-email-quic_eserrao@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Stable-dep-of: 4e8ef34e36 ("usb: dwc3: fix gadget mode suspend interrupt handler issue")
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 3c0f4f09c0 upstream.
The CDC-ECM specification [1] requires to send the host MAC address as
an uppercase hexadecimal string in chapter "5.4 Ethernet Networking
Functional Descriptor":
The Unicode character is chosen from the set of values 30h through
39h and 41h through 46h (0-9 and A-F).
However, snprintf(.., "%pm", ..) generates a lowercase MAC address
string. While most host drivers are tolerant to this, UsbNcm.sys on
Windows 10 is not. Instead it uses a different MAC address with all
bytes set to zero including and after the first byte containing a
lowercase letter. On Windows 11 Microsoft fixed it, but apparently they
did not backport the fix.
This change fixes the issue by upper-casing the MAC to comply with the
specification.
[1]: https://www.usb.org/document-library/class-definitions-communication-devices-12, file ECM120.pdf
Fixes: bcd4a1c40b ("usb: gadget: u_ether: construct with default values and add setters/getters")
Cc: stable@vger.kernel.org
Signed-off-by: Konrad Gräfe <k.graefe@gateware.de>
Link: https://lore.kernel.org/r/20230505143640.443014-1-k.graefe@gateware.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 5629d31955 ]
Commit ac82b56bda ("usb: gadget: tegra-xudc: Add vbus_draw support")
populated the vbus_draw callback for the Tegra XUDC driver. The function
tegra_xudc_gadget_vbus_draw(), that was added by this commit, assumes
that the pointer 'curr_usbphy' has been initialised, which is not always
the case because this is only initialised when the USB role is updated.
Fix this crash, by checking that the 'curr_usbphy' is valid before
dereferencing.
Fixes: ac82b56bda ("usb: gadget: tegra-xudc: Add vbus_draw support")
Reviewed-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Link: https://lore.kernel.org/r/20230405181854.42355-1-jonathanh@nvidia.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 2b947f8769 ]
In renesas_usb3_probe, role_work is bound with renesas_usb3_role_work.
renesas_usb3_start will be called to start the work.
If we remove the driver which will call usbhs_remove, there may be
an unfinished work. The possible sequence is as follows:
CPU0 CPU1
renesas_usb3_role_work
renesas_usb3_remove
usb_role_switch_unregister
device_unregister
kfree(sw)
//free usb3->role_sw
usb_role_switch_set_role
//use usb3->role_sw
The usb3->role_sw could be freed under such circumstance and then
used in usb_role_switch_set_role.
This bug was found by static analysis. And note that removing a
driver is a root-only operation, and should never happen in normal
case. But the root user may directly remove the device which
will also trigger the remove function.
Fix it by canceling the work before cleanup in the renesas_usb3_remove.
Fixes: 39facfa01c ("usb: gadget: udc: renesas_usb3: Add register of usb role switch")
Signed-off-by: Zheng Wang <zyytlz.wz@163.com>
Reviewed-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Link: https://lore.kernel.org/r/20230320062931.505170-1-zyytlz.wz@163.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 6c67ed9ad9 upstream.
In the unbind callback for f_uac1 and f_uac2, a call to snd_card_free()
via g_audio_cleanup() will disconnect the card and then wait for all
resources to be released, which happens when the refcount falls to zero.
Since userspace can keep the refcount incremented by not closing the
relevant file descriptor, the call to unbind may block indefinitely.
This can cause a deadlock during reboot, as evidenced by the following
blocked task observed on my machine:
task:reboot state:D stack:0 pid:2827 ppid:569 flags:0x0000000c
Call trace:
__switch_to+0xc8/0x140
__schedule+0x2f0/0x7c0
schedule+0x60/0xd0
schedule_timeout+0x180/0x1d4
wait_for_completion+0x78/0x180
snd_card_free+0x90/0xa0
g_audio_cleanup+0x2c/0x64
afunc_unbind+0x28/0x60
...
kernel_restart+0x4c/0xac
__do_sys_reboot+0xcc/0x1ec
__arm64_sys_reboot+0x28/0x30
invoke_syscall+0x4c/0x110
...
The issue can also be observed by opening the card with arecord and
then stopping the process through the shell before unbinding:
# arecord -D hw:UAC2Gadget -f S32_LE -c 2 -r 48000 /dev/null
Recording WAVE '/dev/null' : Signed 32 bit Little Endian, Rate 48000 Hz, Stereo
^Z[1]+ Stopped arecord -D hw:UAC2Gadget -f S32_LE -c 2 -r 48000 /dev/null
# echo gadget.0 > /sys/bus/gadget/drivers/configfs-gadget/unbind
(observe that the unbind command never finishes)
Fix the problem by using snd_card_free_when_closed() instead, which will
still disconnect the card as desired, but defer the task of freeing the
resources to the core once userspace closes its file descriptor.
Fixes: 132fcb4608 ("usb: gadget: Add Audio Class 2.0 Driver")
Cc: stable@vger.kernel.org
Signed-off-by: Alvin Šipraga <alsi@bang-olufsen.dk>
Reviewed-by: Ruslan Bilovol <ruslan.bilovol@gmail.com>
Reviewed-by: John Keeping <john@metanate.com>
Link: https://lore.kernel.org/r/20230302163648.3349669-1-alvin@pqrs.dk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 7ebb605d22 upstream.
If kstrtou8() fails, the mutex_unlock() is missed, move kstrtou8()
before mutex_lock() to fix it up.
Fixes: 0525210c98 ("usb: gadget: uvc: Allow definition of XUs in configfs")
Fixes: b3c839bd8a ("usb: gadget: uvc: Make bSourceID read/write")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Link: https://lore.kernel.org/r/20230213070926.776447-1-yangyingliang@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit b3c839bd8a ]
At the moment, the UVC function graph is hardcoded IT -> PU -> OT.
To add XU support we need the ability to insert the XU descriptors
into the chain. To facilitate that, make the output terminal's
bSourceID attribute writeable so that we can configure its source.
Signed-off-by: Daniel Scally <dan.scally@ideasonboard.com>
Link: https://lore.kernel.org/r/20230206161802.892954-2-dan.scally@ideasonboard.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 7a6952fa03 ]
When calling debugfs_lookup() the result must have dput() called on it,
otherwise the memory will leak over time. To make things simpler, just
call debugfs_lookup_and_remove() instead which handles all of the logic
at once.
Cc: Daniel Mack <daniel@zonque.org>
Cc: Haojian Zhuang <haojian.zhuang@gmail.com>
Cc: Robert Jarzmik <robert.jarzmik@free.fr>
Link: https://lore.kernel.org/r/20230202153235.2412790-12-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 7a038a681b ]
When calling debugfs_lookup() the result must have dput() called on it,
otherwise the memory will leak over time. To make things simpler, just
call debugfs_lookup_and_remove() instead which handles all of the logic
at once.
Cc: Daniel Mack <daniel@zonque.org>
Cc: Haojian Zhuang <haojian.zhuang@gmail.com>
Cc: Robert Jarzmik <robert.jarzmik@free.fr>
Link: https://lore.kernel.org/r/20230202153235.2412790-11-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit e3965acaf3 ]
When calling debugfs_lookup() the result must have dput() called on it,
otherwise the memory will leak over time. To make things simpler, just
call debugfs_lookup_and_remove() instead which handles all of the logic
at once.
Cc: Jakob Koschel <jakobkoschel@gmail.com>
Cc: Miaoqian Lin <linmq006@gmail.com>
Acked-by: Vladimir Zapolskiy <vz@mleia.com>
Link: https://lore.kernel.org/r/20230202153235.2412790-10-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit a91c99b1fe ]
When calling debugfs_lookup() the result must have dput() called on it,
otherwise the memory will leak over time. To make things simpler, just
call debugfs_lookup_and_remove() instead which handles all of the logic
at once.
Cc: Kevin Cernekee <cernekee@gmail.com>
Link: https://lore.kernel.org/r/20230202153235.2412790-9-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 73f4451368 ]
When calling debugfs_lookup() the result must have dput() called on it,
otherwise the memory will leak over time. To make things simpler, just
call debugfs_lookup_and_remove() instead which handles all of the logic
at once.
Cc: Jakob Koschel <jakobkoschel@gmail.com>
Link: https://lore.kernel.org/r/20230202153235.2412790-8-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 89e7252d6c ]
During enumeration or composition switch,a userspace process
agnostic of the conventions of configs can try to create function
symlinks even after the UDC is bound to current config which is
not correct. Potentially it can create duplicates within the
current config.
Prevent this by adding a check if udc_name already exists, then bail
out of cfg_link.
Following is an example:
Step1:
ln -s X1 ffs.a
-->cfg_link
--> usb_get_function(ffs.a)
->ffs_alloc
CFG->FUNC_LIST: <ffs.a>
C->FUNCTION: <empty>
Step2:
echo udc.name > /config/usb_gadget/g1/UDC
--> UDC_store
->composite_bind
->usb_add_function
CFG->FUNC_LIST: <empty>
C->FUNCTION: <ffs.a>
Step3:
ln -s Y1 ffs.a
-->cfg_link
-->usb_get_function(ffs.a)
->ffs_alloc
CFG->FUNC_LIST: <ffs.a>
C->FUNCTION: <ffs.a>
both the lists corresponds to the same function instance ffs.a
but the usb_function* pointer is different because in step 3
ffs_alloc has created a new reference to usb_function* for
ffs.a and added it to cfg_list.
Step4:
Now a composition switch involving <ffs.b,ffs.a> is executed.
the composition switch will involve 3 things:
1. unlinking the previous functions existing
2. creating new symlinks
3. writing UDC
However, the composition switch is generally taken care by
userspace process which creates the symlinks in its own
nomenclature(X*) and removes only those.
So it won't be able to remove Y1 which user had created
by own.
Due to this the new symlinks cannot be created for ffs.a
since the entry already exists in CFG->FUNC_LIST.
The state of the CFG->FUNC_LIST is as follows:
CFG->FUNC_LIST: <ffs.a>
Fixes: 88af8bbe4e ("usb: gadget: the start of the configfs interface")
Signed-off-by: Krishna Kurapati PSSNV <quic_kriskura@quicinc.com>
Signed-off-by: Udipto Goswami <quic_ugoswami@quicinc.com>
Link: https://lore.kernel.org/r/20230201132308.31523-1-quic_ugoswami@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 36f4c25ce3 ]
If the list does not contain the expected element, the value of
list_for_each_entry() iterator will not point to a valid structure.
To avoid type confusion in such case, the list iterator
scope will be limited to list_for_each_entry() loop.
In preparation to limiting scope of a list iterator to the list traversal
loop, use a dedicated pointer to point to the found element [1].
Determining if an element was found is then simply checking if
the pointer is != NULL instead of using the potentially bogus pointer.
Link: https://lore.kernel.org/all/YhdfEIwI4EdtHdym@kroah.com/
Signed-off-by: Jakob Koschel <jakobkoschel@gmail.com>
Link: https://lore.kernel.org/r/20220308171818.384491-18-jakobkoschel@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Stable-dep-of: 89e7252d6c ("usb: gadget: configfs: Restrict symlink creation is UDC already binded")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit a8d3392e0e ]
When request_irq(ires1->start) failed in w5300_hw_probe(), irq
ires->start has not been freed, and on the clean_up3 error path,
we also need to free ires1->start irq, fix it.
In addition, We should add free_irq in fusb300_remove(), and give
the lables a proper name so that they can be understood easily,
so add free_irq in fusb300_remove(), and update clean_up3 to
err_alloc_request.
Fixes: 0fe6f1d1f6 ("usb: udc: add Faraday fusb300 driver")
Signed-off-by: Gaosheng Cui <cuigaosheng1@huawei.com>
Link: https://lore.kernel.org/r/20221123014121.1989721-1-cuigaosheng1@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 5ec63fdbca upstream.
Consider a case where gserial_disconnect has already cleared
gser->ioport. And if a wakeup interrupt triggers afterwards,
gserial_resume gets called, which will lead to accessing of
gser->ioport and thus causing null pointer dereference.Add
a null pointer check to prevent this.
Added a static spinlock to prevent gser->ioport from becoming
null after the newly added check.
Fixes: aba3a8d01d ("usb: gadget: u_serial: add suspend resume callbacks")
Cc: stable <stable@kernel.org>
Signed-off-by: Prashanth K <quic_prashk@quicinc.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Link: https://lore.kernel.org/r/1676309438-14922-1-git-send-email-quic_prashk@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 2fa89458af upstream.
Currently connect/disconnect of USB cable calls afunc_bind and
eventually increments the bNumEndpoints. Performing multiple
plugin/plugout will increment bNumEndpoints incorrectly, and on
the next plug-in it leads to invalid configuration of descriptor
and hence enumeration fails.
Fix this by resetting the value of bNumEndpoints to 1 on every
afunc_bind call.
Fixes: 40c73b3054 ("usb: gadget: f_uac2: add adaptive sync support for capture")
Cc: stable <stable@kernel.org>
Signed-off-by: Pratham Pratap <quic_ppratap@quicinc.com>
Signed-off-by: Prashanth K <quic_prashk@quicinc.com>
Link: https://lore.kernel.org/r/1674631645-28888-1-git-send-email-quic_prashk@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 921deb9da1 ]
__ffs_ep0_queue_wait executes holding the spinlock of &ffs->ev.waitq.lock
and unlocks it after the assignments to usb_request are done.
However in the code if the request is already NULL we bail out returning
-EINVAL but never unlocked the spinlock.
Fix this by adding spin_unlock_irq &ffs->ev.waitq.lock before returning.
Fixes: 6a19da1110 ("usb: gadget: f_fs: Prevent race during ffs_ep0_queue_wait")
Reviewed-by: John Keeping <john@metanate.com>
Signed-off-by: Udipto Goswami <quic_ugoswami@quicinc.com>
Link: https://lore.kernel.org/r/20230124091149.18647-1-quic_ugoswami@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit ce405d561b ]
As per the documentation, function usb_ep_free_request guarantees
the request will not be queued or no longer be re-queued (or
otherwise used). However, with the current implementation it
doesn't make sure that the request in ep0 isn't reused.
Fix this by dequeuing the ep0req on functionfs_unbind before
freeing the request to align with the definition.
Fixes: ddf8abd259 ("USB: f_fs: the FunctionFS driver")
Signed-off-by: Udipto Goswami <quic_ugoswami@quicinc.com>
Tested-by: Krishna Kurapati <quic_kriskura@quicinc.com>
Link: https://lore.kernel.org/r/20221215052906.8993-3-quic_ugoswami@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 6a19da1110 ]
While performing fast composition switch, there is a possibility that the
process of ffs_ep0_write/ffs_ep0_read get into a race condition
due to ep0req being freed up from functionfs_unbind.
Consider the scenario that the ffs_ep0_write calls the ffs_ep0_queue_wait
by taking a lock &ffs->ev.waitq.lock. However, the functionfs_unbind isn't
bounded so it can go ahead and mark the ep0req to NULL, and since there
is no NULL check in ffs_ep0_queue_wait we will end up in use-after-free.
Fix this by making a serialized execution between the two functions using
a mutex_lock(ffs->mutex).
Fixes: ddf8abd259 ("USB: f_fs: the FunctionFS driver")
Signed-off-by: Udipto Goswami <quic_ugoswami@quicinc.com>
Tested-by: Krishna Kurapati <quic_kriskura@quicinc.com>
Link: https://lore.kernel.org/r/20221215052906.8993-2-quic_ugoswami@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit c6ec929595 upstream.
In Google internal bug 265639009 we've received an (as yet) unreproducible
crash report from an aarch64 GKI 5.10.149-android13 running device.
AFAICT the source code is at:
https://android.googlesource.com/kernel/common/+/refs/tags/ASB-2022-12-05_13-5.10
The call stack is:
ncm_close() -> ncm_notify() -> ncm_do_notify()
with the crash at:
ncm_do_notify+0x98/0x270
Code: 79000d0b b9000a6c f940012a f9400269 (b9405d4b)
Which I believe disassembles to (I don't know ARM assembly, but it looks sane enough to me...):
// halfword (16-bit) store presumably to event->wLength (at offset 6 of struct usb_cdc_notification)
0B 0D 00 79 strh w11, [x8, #6]
// word (32-bit) store presumably to req->Length (at offset 8 of struct usb_request)
6C 0A 00 B9 str w12, [x19, #8]
// x10 (NULL) was read here from offset 0 of valid pointer x9
// IMHO we're reading 'cdev->gadget' and getting NULL
// gadget is indeed at offset 0 of struct usb_composite_dev
2A 01 40 F9 ldr x10, [x9]
// loading req->buf pointer, which is at offset 0 of struct usb_request
69 02 40 F9 ldr x9, [x19]
// x10 is null, crash, appears to be attempt to read cdev->gadget->max_speed
4B 5D 40 B9 ldr w11, [x10, #0x5c]
which seems to line up with ncm_do_notify() case NCM_NOTIFY_SPEED code fragment:
event->wLength = cpu_to_le16(8);
req->length = NCM_STATUS_BYTECOUNT;
/* SPEED_CHANGE data is up/down speeds in bits/sec */
data = req->buf + sizeof *event;
data[0] = cpu_to_le32(ncm_bitrate(cdev->gadget));
My analysis of registers and NULL ptr deref crash offset
(Unable to handle kernel NULL pointer dereference at virtual address 000000000000005c)
heavily suggests that the crash is due to 'cdev->gadget' being NULL when executing:
data[0] = cpu_to_le32(ncm_bitrate(cdev->gadget));
which calls:
ncm_bitrate(NULL)
which then calls:
gadget_is_superspeed(NULL)
which reads
((struct usb_gadget *)NULL)->max_speed
and hits a panic.
AFAICT, if I'm counting right, the offset of max_speed is indeed 0x5C.
(remember there's a GKI KABI reservation of 16 bytes in struct work_struct)
It's not at all clear to me how this is all supposed to work...
but returning 0 seems much better than panic-ing...
Cc: Felipe Balbi <balbi@kernel.org>
Cc: Lorenzo Colitti <lorenzo@google.com>
Cc: Carlos Llamas <cmllamas@google.com>
Cc: stable@vger.kernel.org
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Cc: stable <stable@kernel.org>
Link: https://lore.kernel.org/r/20230117131839.1138208-1-maze@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit e95765e97d upstream.
Currently the color matching descriptor is only sent across the wire
a single time, following the descriptors for each format and frame.
According to the UVC 1.5 Specification 3.9.2.6 ("Color Matching
Descriptors"):
"Only one instance is allowed for a given format and if present,
the Color Matching descriptor shall be placed following the Video
and Still Image Frame descriptors for that format".
Add another reference to the color matching descriptor after the
yuyv frames so that it's correctly transmitted for that format
too.
Fixes: a9914127e8 ("USB gadget: Webcam device")
Cc: stable <stable@kernel.org>
Signed-off-by: Daniel Scally <dan.scally@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Link: https://lore.kernel.org/r/20221216160528.479094-1-dan.scally@ideasonboard.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit d18dcfe986 upstream.
The syzbot fuzzer and Gerald Lee have identified a use-after-free bug
in the gadgetfs driver, involving processes concurrently mounting and
unmounting the gadgetfs filesystem. In particular, gadgetfs_fill_super()
can race with gadgetfs_kill_sb(), causing the latter to deallocate
the_device while the former is using it. The output from KASAN says,
in part:
BUG: KASAN: use-after-free in instrument_atomic_read_write include/linux/instrumented.h:102 [inline]
BUG: KASAN: use-after-free in atomic_fetch_sub_release include/linux/atomic/atomic-instrumented.h:176 [inline]
BUG: KASAN: use-after-free in __refcount_sub_and_test include/linux/refcount.h:272 [inline]
BUG: KASAN: use-after-free in __refcount_dec_and_test include/linux/refcount.h:315 [inline]
BUG: KASAN: use-after-free in refcount_dec_and_test include/linux/refcount.h:333 [inline]
BUG: KASAN: use-after-free in put_dev drivers/usb/gadget/legacy/inode.c:159 [inline]
BUG: KASAN: use-after-free in gadgetfs_kill_sb+0x33/0x100 drivers/usb/gadget/legacy/inode.c:2086
Write of size 4 at addr ffff8880276d7840 by task syz-executor126/18689
CPU: 0 PID: 18689 Comm: syz-executor126 Not tainted 6.1.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
Call Trace:
<TASK>
...
atomic_fetch_sub_release include/linux/atomic/atomic-instrumented.h:176 [inline]
__refcount_sub_and_test include/linux/refcount.h:272 [inline]
__refcount_dec_and_test include/linux/refcount.h:315 [inline]
refcount_dec_and_test include/linux/refcount.h:333 [inline]
put_dev drivers/usb/gadget/legacy/inode.c:159 [inline]
gadgetfs_kill_sb+0x33/0x100 drivers/usb/gadget/legacy/inode.c:2086
deactivate_locked_super+0xa7/0xf0 fs/super.c:332
vfs_get_super fs/super.c:1190 [inline]
get_tree_single+0xd0/0x160 fs/super.c:1207
vfs_get_tree+0x88/0x270 fs/super.c:1531
vfs_fsconfig_locked fs/fsopen.c:232 [inline]
The simplest solution is to ensure that gadgetfs_fill_super() and
gadgetfs_kill_sb() are serialized by making them both acquire a new
mutex.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Reported-and-tested-by: syzbot+33d7ad66d65044b93f16@syzkaller.appspotmail.com
Reported-and-tested-by: Gerald Lee <sundaywind2004@gmail.com>
Link: https://lore.kernel.org/linux-usb/CAO3qeMVzXDP-JU6v1u5Ags6Q-bb35kg3=C6d04DjzA9ffa5x1g@mail.gmail.com/
Fixes: e5d82a7360 ("vfs: Convert gadgetfs to use the new mount API")
CC: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/Y6XCPXBpn3tmjdCC@rowland.harvard.edu
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 70a3288a75 ]
When failing to allocate report_desc, opts->refcnt has already been
incremented so it needs to be decremented to avoid leaving the options
structure permanently locked.
Fixes: 21a9476a7b ("usb: gadget: hid: add configfs support")
Tested-by: Lee Jones <lee@kernel.org>
Reviewed-by: Andrzej Pietrasiewicz <andrzej.p@collabora.com>
Reviewed-by: Lee Jones <lee@kernel.org>
Signed-off-by: John Keeping <john@metanate.com>
Link: https://lore.kernel.org/r/20221122123523.3068034-3-john@metanate.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 89ff3dfac6 ]
The embedded struct cdev does not have its lifetime correctly tied to
the enclosing struct f_hidg, so there is a use-after-free if /dev/hidgN
is held open while the gadget is deleted.
This can readily be replicated with libusbgx's example programs (for
conciseness - operating directly via configfs is equivalent):
gadget-hid
exec 3<> /dev/hidg0
gadget-vid-pid-remove
exec 3<&-
Pull the existing device up in to struct f_hidg and make use of the
cdev_device_{add,del}() helpers. This changes the lifetime of the
device object to match struct f_hidg, but note that it is still added
and deleted at the same time.
Fixes: 71adf11894 ("USB: gadget: add HID gadget driver")
Tested-by: Lee Jones <lee@kernel.org>
Reviewed-by: Andrzej Pietrasiewicz <andrzej.p@collabora.com>
Reviewed-by: Lee Jones <lee@kernel.org>
Signed-off-by: John Keeping <john@metanate.com>
Link: https://lore.kernel.org/r/20221122123523.3068034-2-john@metanate.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 46ed6026ca ]
The code in the FOTG210 driver isn't entirely endianness-agnostic
as reported by the kernel robot sparse testing. This came to
the surface while moving the files around.
The driver is only used on little-endian systems, so this causes
no real-world regression, but it is nice to be strict and have
some compile coverage also on big endian machines, so fix it
up with the right LE accessors.
Fixes: b84a8dee23 ("usb: gadget: add Faraday fotg210_udc driver")
Reported-by: kernel test robot <lkp@intel.com>
Link: https://lore.kernel.org/linux-usb/202211110910.0dJ7nZCn-lkp@intel.com/
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20221111090317.94228-1-linus.walleij@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 4c92670b16 upstream.
Setup function uvc_function_setup permits control transfer
requests with up to 64 bytes of payload (UVC_MAX_REQUEST_SIZE),
data stage handler for OUT transfer uses memcpy to copy req->actual
bytes to uvc_event->data.data array of size 60. This may result
in an overflow of 4 bytes.
Fixes: cdda479f15 ("USB gadget: video class function driver")
Cc: stable <stable@kernel.org>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Daniel Scally <dan.scally@ideasonboard.com>
Signed-off-by: Szymon Heidrich <szymon.heidrich@gmail.com>
Link: https://lore.kernel.org/r/20221206141301.51305-1-szymon.heidrich@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit fb8f60dd1b upstream.
When port is connected and then disconnected, the state stays as
configured. Which is incorrect as the port is no longer configured,
but in a not attached state.
Signed-off-by: Justin Chen <justinpopo6@gmail.com>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Fixes: efed421a94 ("usb: gadget: Add UDC driver for Broadcom USB3.0 device controller IP BDC")
Cc: stable <stable@kernel.org>
Link: https://lore.kernel.org/r/1664997235-18198-1-git-send-email-justinpopo6@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit b57b08e6f4 upstream.
In uvc_video_encode_isoc_sg, the uvc_request's sg list is
incorrectly being populated leading to corrupt video being
received by the remote end. When building the sg list the
usage of buf->sg's 'dma_length' field is not correct and
instead its 'length' field should be used.
Fixes: e81e7f9a0e ("usb: gadget: uvc: add scatter gather support")
Cc: <stable@vger.kernel.org>
Signed-off-by: Jeff Vanhoof <qjv001@motorola.com>
Signed-off-by: Dan Vacura <w36195@motorola.com>
Link: https://lore.kernel.org/r/20221018215044.765044-5-w36195@motorola.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 0a0a2760b0 upstream.
If there is a transmission error the buffer will be returned too early,
causing a memory fault as subsequent requests for that buffer are still
queued up to be sent. Refactor the error handling to wait for the final
request to come in before reporting back the buffer to userspace for all
transfer types (bulk/isoc/isoc_sg). This ensures userspace knows if the
frame was successfully sent.
Fixes: e81e7f9a0e ("usb: gadget: uvc: add scatter gather support")
Cc: <stable@vger.kernel.org>
Signed-off-by: Dan Vacura <w36195@motorola.com>
Link: https://lore.kernel.org/r/20221018215044.765044-4-w36195@motorola.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit aef1127988 upstream.
The exit condition to quit iterating over the sg_list, while encoding
the sg entries, has to consider the case that the dma_len of the entry
could be zero. This patch takes this condition to account.
Signed-off-by: Michael Grzeschik <m.grzeschik@pengutronix.de>
Link: https://lore.kernel.org/r/20220402232744.3622565-4-m.grzeschik@pengutronix.de
Cc: Dan Vacura <w36195@motorola.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 9b969f93bc upstream.
On uvc_video_encode_isoc_sg the mapped vb2 buffer is returned
to early. Only after the last usb_request worked with the buffer
it is allowed to give it back to vb2. This patch fixes that.
Signed-off-by: Michael Grzeschik <m.grzeschik@pengutronix.de>
Link: https://lore.kernel.org/r/20220402232744.3622565-3-m.grzeschik@pengutronix.de
Cc: Dan Vacura <w36195@motorola.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Roy Luo
Konstantin Aladyshev
Hardik Gajjar
Andrey Konovalov
Krishna Kurapati
Piyush Mehta
Ma Ke
Alan Stern
Prashanth K
Zqiang
Frank Li
Dan Carpenter
Uttkarsh Aggarwal
Elson Roy Serrao
Konrad Gräfe
Jon Hunter
Zheng Wang
Alvin Šipraga
Yang Yingliang
Daniel Scally
Greg Kroah-Hartman
Udipto Goswami
Jakob Koschel
Linyu Yuan
Fabian Vogt
Gaosheng Cui
Pratham Pratap
Maciej Żenczykowski
John Keeping
Linus Walleij
Szymon Heidrich
Justin Chen
Jeff Vanhoof
Dan Vacura
Michael Grzeschik