The variable status is being initialized with a value that is never read
and it is being updated later with a new value. The initialization is
redundant and can be removed.
Addresses-Coverity: ("Unused value")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
A malicious USB device may lack endpoints the driver assumes to exist
Accessing them leads to NULL pointer accesses. This patch introduces
sanity checking.
Reported-and-tested-by: syzbot+cabfa4b5b05ff6be4ef0@syzkaller.appspotmail.com
Signed-off-by: Oliver Neukum <oneukum@suse.com>
Fixes: 866b8695d6 ("Staging: add the go7007 video driver")
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
The variable err is being initialized with a value that is
never read and it is being updated later with a new value. The
initialization is redundant and can be removed.
Addresses-Coverity: ("Unused value")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:
struct foo {
int stuff;
struct boo array[];
};
By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.
Also, notice that, dynamic memory allocations won't be affected by
this change:
"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]
This issue was found with the help of Coccinelle.
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
MyGica T230* receivers also do DVB-C and DVB-T: change their names.
Signed-off-by: Jan Pieter van Woerkom <jp@jpvw.nl>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
CONFIG_DVB_USB_CXUSB_ANALOG is a 'bool' symbol with a dependency on the
tristate CONFIG_VIDEO_V4L2, which means it can be enabled as =y even
when its dependency is =m. This leads to a link failure:
drivers/media/usb/dvb-usb/cxusb-analog.o: In function `cxusb_medion_analog_init':
cxusb-analog.c:(.text+0x92): undefined reference to `v4l2_subdev_call_wrappers'
drivers/media/usb/dvb-usb/cxusb-analog.o: In function `cxusb_medion_register_analog':
cxusb-analog.c:(.text+0x466): undefined reference to `v4l2_device_register'
cxusb-analog.c:(.text+0x4c3): undefined reference to `v4l2_i2c_new_subdev'
cxusb-analog.c:(.text+0x4fb): undefined reference to `v4l2_subdev_call_wrappers'
...
Change the dependency only disallow the analog portion of the driver
in that configuration.
Fixes: e478d40540 ("media: cxusb: add analog mode support for Medion MD95700")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
The variable retval is being initialized with a value that is
never read and it is being updated later with a new value. The
initialization is redundant and can be removed.
Addresses-Coverity: ("Unused value")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Terratec Cinergy S2 PCIe Dual is a PCIe device with two tuners that
actually contains two USB devices. The devices are visible in the
lsusb printout.
Bus 004 Device 002: ID 153b:1182 TerraTec Electronic GmbH Cinergy S2 PCIe Dual Port 2
Bus 003 Device 002: ID 153b:1181 TerraTec Electronic GmbH Cinergy S2 PCIe Dual Port 1
The devices use the Montage M88DS3000/M88TS2022 demod/tuner.
Signed-off-by: Dirk Nehring <dnehring@gmx.net>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
In ttusb_dec_handle_irq(), buffer[4] is continuously read from memory
three times, without being modified.
To reduce the number of memory reads, buffer[4] is first assigned to a
local variable index, and then index is used to replace buffer[4].
Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
The USB_DEVICE() list contain some of the product names, but
some are missing, and others are different than the message
printed during device detection.
Update the comments in order to match what the driver prints.
That makes easier to discover what model matches what physical
device.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Instead of using USB_DEVICE() macro directly, use the
DVB_USB_DEVICE() one, as other dvb-usb-v2 devices.
The usage of the new macro makes cleaner and easier to
parse the supported device names in a way that it would
be easily parseable to generate cardlists.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
The boards listed below use i2c device drivers and have
tuner_type equal TUNER_ABSENT. This means additional support
is required to enable the analog tuning capability, a case
statement is used to identify these models.
Models with analog tuning enabled:
- CX231XX_BOARD_HAUPPAUGE_930C_HD_1114xx (tested)
- CX231XX_BOARD_HAUPPAUGE_935C (tested)
- CX231XX_BOARD_HAUPPAUGE_955Q (tested)
- CX231XX_BOARD_HAUPPAUGE_975 (tested)
- CX231XX_BOARD_EVROMEDIA_FULL_HYBRID_FULLHD (untested)
The EvroMedia model was added, since it uses the si2157
tuner and the board profile claims it has analog inputs.
Signed-off-by: Brad Love <brad@nextdimension.cc>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
The variable status is being assigned a value that is never read.
The assignment is redundant and can be removed.
Addresses-Coverity: ("Unused value")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Ezequiel Garcia <ezequiel@collabora.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
The variable ret is being initialized with a value that is never read
and it is being updated later with a new value. The initialization is
redundant and can be removed.
Addresses-Coverity: ("Unused value")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Ezequiel Garcia <ezequiel@collabora.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
This makes it possible to declare dvb_usb_device_properties const.
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Currently when i2c transfers fail the error return -EREMOTEIO
is assigned to err but then later overwritten when the tuner
attach call is made. Fix this by returning early with the
error return code -EREMOTEIO on i2c transfer failure errors.
If the transfer fails, an uninitialized value will be read from b2.
Addresses-Coverity: ("Unused value")
Fixes: fbfee8684f ("V4L/DVB (5651): Dibusb-mb: convert pll handling to properly use dvb-pll")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
The first element of the key array is not used. Remove it, and
along with it a uninitialized memory read.
This should fix the rc debug message.
Link: https://www.spinics.net/lists/kernel/msg3374861.html
Suggested-by: Phong Tran <tranmanphong@gmail.com>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
As CEC support doesn't depend on MEDIA_SUPPORT, let's
place the platform drivers outside the media menu.
As a side effect, instead of depends on USB, drivers
just select it.
Acked-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Move away from the deprecated API.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Mike Isely <isely@pobox.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Move away from the deprecated API and return the shiny new ERRPTR where
useful.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Move away from the deprecated API and make use of the fact that
unregistering devices is NULL- and ERR_PTR-safe.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Changing from "depends on" to "select" may cause some
side-effects. This patch is not ready to be merged yet,
as it requires some adjustments.
So, let's revert it.
This reverts commit a3b91d8bd1.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Those documents don't really describe the driver API.
Instead, they contain development-specific information.
Yet, as the main index file describes the content of it as:
"how specific kernel subsystems work
from the point of view of a kernel developer"
It seems to be the better fit.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Most of the driver-specific documentation is meant to help
users of the media subsystem.
Move them to the admin-guide.
It should be noticed, however, that several of those files
are outdated and will require further work in order to make
them useful again.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Right now, if one has an hybrid TV card, it has to select
both analog and digital TV support, as otherwise the needed
core support won't be selected.
Change the logic to auto-select the core support for those
drivers, as this is a way more intuitive.
It should be noticed that, as now both DVB_CORE and VIDEO_DEV
defaults depends on selecting a hybrid cards, we had to remove
the explicit dependencies there, in order to avoid circular
dependencies.
That requires some tricks:
1) the prompt should not be not visible when an hybrid card
is selected, as the user shold not change it.
2) When a media hybrid device is selected, the modular
option for DVB_CORE and VIDEO_DEV will follow the
MEDIA_SUPPORT dependency, as we can't have a core
built with "y" with a driver built as module.
Note: while here, moved two pure V4L2 PCI drivers out of the
"hybrid" part of config and consider pvrusb2 as an hybrid
device.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
This option is used only by av7110 and by an USB driver. As
the av7110 is the first DVB hardware, hardly found those
days, let's opt to place it at usb/Kconfig, as the driver
with needs it might have a longer lifetime.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
At least some of the supported boards by dvb-usb
driver need to load the cypress firmware, so select
it, as otherwise missing dependencies may popup.
Also, as the cypress firmware load routines are needed
only by the dvb-usb, dvb-usb-v2 and go7007 drivers, and
those all (now) select it, there's no need to ask the
user for manually select it.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Make sure to check that we have two alternate settings and at least one
endpoint before accessing the second altsetting structure and
dereferencing the endpoint arrays.
This specifically avoids dereferencing NULL-pointers or corrupting
memory when a device does not have the expected descriptors.
Note that the sanity check in cit_get_packet_size() is not redundant as
the driver is mixing looking up altsettings by index and by number,
which may not coincide.
Fixes: 659fefa0eb ("V4L/DVB: gspca_xirlink_cit: Add support for camera with a bcd version of 0.01")
Fixes: 59f8b0bf3c ("V4L/DVB: gspca_xirlink_cit: support bandwidth changing for devices with 1 alt setting")
Cc: stable <stable@vger.kernel.org> # 2.6.37
Cc: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Make sure to check that we have two alternate settings and at least one
endpoint before accessing the second altsetting structure and
dereferencing the endpoint arrays.
This specifically avoids dereferencing NULL-pointers or corrupting
memory when a device does not have the expected descriptors.
Note that the sanity checks in stv06xx_start() and pb0100_start() are
not redundant as the driver is mixing looking up altsettings by index
and by number, which may not coincide.
Fixes: 8668d504d7 ("V4L/DVB (12082): gspca_stv06xx: Add support for st6422 bridge and sensor")
Fixes: c0b33bdc5b ("[media] gspca-stv06xx: support bandwidth changing")
Cc: stable <stable@vger.kernel.org> # 2.6.31
Cc: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Make sure to check that we have at least one endpoint before accessing
the endpoint array to avoid dereferencing a NULL-pointer on stream
start.
Note that these sanity checks are not redundant as the driver is mixing
looking up altsettings by index and by number, which need not coincide.
Fixes: 1876bb923c ("V4L/DVB (12079): gspca_ov519: add support for the ov511 bridge")
Fixes: b282d87332 ("V4L/DVB (12080): gspca_ov519: Fix ov518+ with OV7620AE (Trust spacecam 320)")
Cc: stable <stable@vger.kernel.org> # 2.6.31
Cc: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
The variable gate is being initialized and also checked and re-assigned
with values that are never read as it is being re-assigned later in a
for-loop with a new value. The assignments are redundant and can be
removed.
Addresses Coverity ("Unused value")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
This is required to support the Terratec S2 USB Box Revision 4, which
reused usb vid:pid, but has a different demodulator (m88ds3103b) at
i2c address 0x6a.
[fixed checkpatch issues]
Signed-off-by: Michael Bunk <micha@freedict.org>
Signed-off-by: Brad Love <brad@nextdimension.cc>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Hauppauge 461e rev2 is a DVB-S/S2 usb device containing:
- m88ds3103b demod
- ts2022 tuner
- A8293 SEC
Device is the same as Hauppauge 461e,
except it contains updated m88ds3103b demod.
Signed-off-by: Brad Love <brad@nextdimension.cc>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Josef reported that his old-and-good Plextor ConvertX M402U video
converter spews lots of WARNINGs on the recent kernels, and it turned
out that the device uses a bulk endpoint for interrupt handling just
like 2250 board.
For fixing it, generalize the check with the proper verification of
the endpoint instead of hard-coded board type check.
Fixes: 7e5219d18e ("[media] go7007: Fix 2250 urb type")
Reported-and-tested-by: Josef Möllers <josef.moellers@suse.com>
BugLink: https://bugzilla.suse.com/show_bug.cgi?id=1162583
BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=206427
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
The driver is deprecated and scheduled for removal by the end
of 2020. The reason is that this driver is for old and obsolete
hardware, and it produces a continuous stream of syzbot errors due
to poor code.
In order to prevent removal the following actions would have to
be taken:
- clean up the code
- convert to the vb2 framework
- fix the disconnect and free-on-last-user handling (i.e., add
a release callback for struct v4l2_device and rework the code
to use that correctly).
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Slave demod needs some time to wake up otherwise it may not respond to the
following probe commands. This problem manifested randomly on my Astrometa
DVB-T2 dongle.
Signed-off-by: Mario Hros <git@reversity.org>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
'GRABBER' is a weird name, all other types map to the /dev
device names. Rename to 'VIDEO' to be consistent with the
other types.
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Make sure to use the current alternate setting when verifying the
interface descriptors to avoid submitting an URB to an invalid endpoint.
Failing to do so could cause the driver to misbehave or trigger a WARN()
in usb_submit_urb() that kernels with panic_on_warn set would choke on.
Fixes: c4018fa2e4 ("[media] dib0700: fix RC support on Hauppauge Nova-TD")
Cc: stable <stable@vger.kernel.org> # 3.16
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
commit 1b976fc6d6 ("media: b2c2-flexcop-usb: add sanity checking") added
an endpoint sanity check to address a NULL-pointer dereference on probe.
Unfortunately the check was done on the current altsetting which was later
changed.
Fix this by moving the sanity check to after the altsetting is changed.
Fixes: 1b976fc6d6 ("media: b2c2-flexcop-usb: add sanity checking")
Cc: Oliver Neukum <oneukum@suse.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
The driver was issuing synchronous uninterruptible control requests
without using a timeout. This could lead to the driver hanging on
various user requests due to a malfunctioning (or malicious) device
until the device is physically disconnected.
The USB upper limit of five seconds per request should be more than
enough.
Fixes: f3d27f34fd ("[media] usbtv: Add driver for Fushicai USBTV007 video frame grabber")
Fixes: c53a846c48 ("[media] usbtv: add video controls")
Cc: stable <stable@vger.kernel.org> # 3.11
Signed-off-by: Johan Hovold <johan@kernel.org>
Acked-by: Lubomir Rintel <lkundrak@v3.sk>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
The hauppauge_955q_lgdt3306a_config structure is only copied
into another structure, so make it const.
The opportunity for this change was found using Coccinelle.
Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
The anysee_tda18212_config and anysee_tda18212_config2 structures
are only copied into other structures, so make them const.
The opportunity for this change was found using Coccinelle.
Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
The serio_close() call was moved to pulse8_cec_adap_free(),
but that can be too late if that is called after the serio
core pulled down the serio already, in which case you get
a kernel oops.
Keep it in the disconnect().
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Fixes: 601282d65b ("media: pulse8-cec: use adap_free callback")
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
If earlier in the connect() an error occurred, then pulse8_cec_adap_free
was called by cec_delete_adapter, and that free function tried to
cancel the ping_eeprom_work workqueue, but that workqueue hasn't
been initialized yet, resulting in a kernel warning.
Move the initialization of that workqueue up to where the other
workqueues are initialized.
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Fixes: 601282d65b ("media: pulse8-cec: use adap_free callback")
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
This device does not function correctly in raw mode in kernel
versions validating buffer sizes in bulk mode. It erroneously
announces 16 bits per pixel instead of 12 for NV12 format, so it
needs this quirk to fix computed frame size and avoid legitimate
frames getting discarded.
[Move info and div variables to local scope]
Signed-off-by: Sergey Zakharchenko <szakharchenko@digital-loggers.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Way back in 2017, fuzzing the 4.14-rc2 USB stack with syzkaller kicked
up the following WARNING from the UVC chain scanning code:
| list_add double add: new=ffff880069084010, prev=ffff880069084010,
| next=ffff880067d22298.
| ------------[ cut here ]------------
| WARNING: CPU: 1 PID: 1846 at lib/list_debug.c:31 __list_add_valid+0xbd/0xf0
| Modules linked in:
| CPU: 1 PID: 1846 Comm: kworker/1:2 Not tainted
| 4.14.0-rc2-42613-g1488251d1a98 #238
| Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
| Workqueue: usb_hub_wq hub_event
| task: ffff88006b01ca40 task.stack: ffff880064358000
| RIP: 0010:__list_add_valid+0xbd/0xf0 lib/list_debug.c:29
| RSP: 0018:ffff88006435ddd0 EFLAGS: 00010286
| RAX: 0000000000000058 RBX: ffff880067d22298 RCX: 0000000000000000
| RDX: 0000000000000058 RSI: ffffffff85a58800 RDI: ffffed000c86bbac
| RBP: ffff88006435dde8 R08: 1ffff1000c86ba52 R09: 0000000000000000
| R10: 0000000000000002 R11: 0000000000000000 R12: ffff880069084010
| R13: ffff880067d22298 R14: ffff880069084010 R15: ffff880067d222a0
| FS: 0000000000000000(0000) GS:ffff88006c900000(0000) knlGS:0000000000000000
| CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
| CR2: 0000000020004ff2 CR3: 000000006b447000 CR4: 00000000000006e0
| Call Trace:
| __list_add ./include/linux/list.h:59
| list_add_tail+0x8c/0x1b0 ./include/linux/list.h:92
| uvc_scan_chain_forward.isra.8+0x373/0x416
| drivers/media/usb/uvc/uvc_driver.c:1471
| uvc_scan_chain drivers/media/usb/uvc/uvc_driver.c:1585
| uvc_scan_device drivers/media/usb/uvc/uvc_driver.c:1769
| uvc_probe+0x77f2/0x8f00 drivers/media/usb/uvc/uvc_driver.c:2104
Looking into the output from usbmon, the interesting part is the
following data packet:
ffff880069c63e00 30710169 C Ci:1:002:0 0 143 = 09028f00 01030080
00090403 00000e01 00000924 03000103 7c003328 010204db
If we drop the lead configuration and interface descriptors, we're left
with an output terminal descriptor describing a generic display:
/* Output terminal descriptor */
buf[0] 09
buf[1] 24
buf[2] 03 /* UVC_VC_OUTPUT_TERMINAL */
buf[3] 00 /* ID */
buf[4] 01 /* type == 0x0301 (UVC_OTT_DISPLAY) */
buf[5] 03
buf[6] 7c
buf[7] 00 /* source ID refers to self! */
buf[8] 33
The problem with this descriptor is that it is self-referential: the
source ID of 0 matches itself! This causes the 'struct uvc_entity'
representing the display to be added to its chain list twice during
'uvc_scan_chain()': once via 'uvc_scan_chain_entity()' when it is
processed directly from the 'dev->entities' list and then again
immediately afterwards when trying to follow the source ID in
'uvc_scan_chain_forward()'
Add a check before adding an entity to a chain list to ensure that the
entity is not already part of a chain.
Link: https://lore.kernel.org/linux-media/CAAeHK+z+Si69jUR+N-SjN9q4O+o5KFiNManqEa-PjUta7EOb7A@mail.gmail.com/
Cc: <stable@vger.kernel.org>
Fixes: c0efd23292 ("V4L/DVB (8145a): USB Video Class driver")
Reported-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
