<feed xmlns='http://www.w3.org/2005/Atom'>
<title>kernel/linux.git/drivers/staging/comedi, branch v4.19.77</title>
<subtitle>Linux kernel stable tree (mirror)</subtitle>
<id>https://git.radix-linux.su/kernel/linux.git/atom?h=v4.19.77</id>
<link rel='self' href='https://git.radix-linux.su/kernel/linux.git/atom?h=v4.19.77'/>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/'/>
<updated>2019-08-25T08:47:59+00:00</updated>
<entry>
<title>staging: comedi: dt3000: Fix rounding up of timer divisor</title>
<updated>2019-08-25T08:47:59+00:00</updated>
<author>
<name>Ian Abbott</name>
<email>abbotti@mev.co.uk</email>
</author>
<published>2019-08-12T12:08:14+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=dac96992f00aedbf988cb91da3b12cb07b6632d8'/>
<id>urn:sha1:dac96992f00aedbf988cb91da3b12cb07b6632d8</id>
<content type='text'>
commit 8e2a589a3fc36ce858d42e767c3bcd8fc62a512b upstream.

`dt3k_ns_to_timer()` determines the prescaler and divisor to use to
produce a desired timing period.  It is influenced by a rounding mode
and can round the divisor up, down, or to the nearest value.  However,
the code for rounding up currently does the same as rounding down!  Fix
ir by using the `DIV_ROUND_UP()` macro to calculate the divisor when
rounding up.

Also, change the types of the `divider`, `base` and `prescale` variables
from `int` to `unsigned int` to avoid mixing signed and unsigned types
in the calculations.

Also fix a typo in a nearby comment: "improvment" =&gt; "improvement".

Signed-off-by: Ian Abbott &lt;abbotti@mev.co.uk&gt;
Cc: stable &lt;stable@vger.kernel.org&gt;
Link: https://lore.kernel.org/r/20190812120814.21188-1-abbotti@mev.co.uk
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>staging: comedi: dt3000: Fix signed integer overflow 'divider * base'</title>
<updated>2019-08-25T08:47:59+00:00</updated>
<author>
<name>Ian Abbott</name>
<email>abbotti@mev.co.uk</email>
</author>
<published>2019-08-12T11:15:17+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=2e394bcfdcf35ee49a09b441b01c0b7a105ea72f'/>
<id>urn:sha1:2e394bcfdcf35ee49a09b441b01c0b7a105ea72f</id>
<content type='text'>
commit b4d98bc3fc93ec3a58459948a2c0e0c9b501cd88 upstream.

In `dt3k_ns_to_timer()` the following lines near the end of the function
result in a signed integer overflow:

	prescale = 15;
	base = timer_base * (1 &lt;&lt; prescale);
	divider = 65535;
	*nanosec = divider * base;

(`divider`, `base` and `prescale` are type `int`, `timer_base` and
`*nanosec` are type `unsigned int`.  The value of `timer_base` will be
either 50 or 100.)

The main reason for the overflow is that the calculation for `base` is
completely wrong.  It should be:

	base = timer_base * (prescale + 1);

which matches an earlier instance of this calculation in the same
function.

Reported-by: David Binderman &lt;dcb314@hotmail.com&gt;
Cc: &lt;stable@vger.kernel.org&gt;
Signed-off-by: Ian Abbott &lt;abbotti@mev.co.uk&gt;
Link: https://lore.kernel.org/r/20190812111517.26803-1-abbotti@mev.co.uk
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>staging: comedi: amplc_pci230: fix null pointer deref on interrupt</title>
<updated>2019-07-14T06:11:20+00:00</updated>
<author>
<name>Ian Abbott</name>
<email>abbotti@mev.co.uk</email>
</author>
<published>2019-06-26T13:17:39+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=c04c751bef8784347ccafeab01e109354240164b'/>
<id>urn:sha1:c04c751bef8784347ccafeab01e109354240164b</id>
<content type='text'>
commit 7379e6baeddf580d01feca650ec1ad508b6ea8ee upstream.

The interrupt handler `pci230_interrupt()` causes a null pointer
dereference for a PCI260 card.  There is no analog output subdevice for
a PCI260.  The `dev-&gt;write_subdev` subdevice pointer and therefore the
`s_ao` subdevice pointer variable will be `NULL` for a PCI260.  The
following call near the end of the interrupt handler results in the null
pointer dereference for a PCI260:

	comedi_handle_events(dev, s_ao);

Fix it by only calling the above function if `s_ao` is valid.

Note that the other uses of `s_ao` in the calls
`pci230_handle_ao_nofifo(dev, s_ao);` and `pci230_handle_ao_fifo(dev,
s_ao);` will never be reached for a PCI260, so they are safe.

Fixes: 39064f23284c ("staging: comedi: amplc_pci230: use comedi_handle_events()")
Cc: &lt;stable@vger.kernel.org&gt; # v3.19+
Signed-off-by: Ian Abbott &lt;abbotti@mev.co.uk&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>staging: comedi: dt282x: fix a null pointer deref on interrupt</title>
<updated>2019-07-14T06:11:20+00:00</updated>
<author>
<name>Ian Abbott</name>
<email>abbotti@mev.co.uk</email>
</author>
<published>2019-06-26T13:18:04+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=4e49c6c91c18330409bd5181ccf73c6382e72c0b'/>
<id>urn:sha1:4e49c6c91c18330409bd5181ccf73c6382e72c0b</id>
<content type='text'>
commit b8336be66dec06bef518030a0df9847122053ec5 upstream.

The interrupt handler `dt282x_interrupt()` causes a null pointer
dereference for those supported boards that have no analog output
support.  For these boards, `dev-&gt;write_subdev` will be `NULL` and
therefore the `s_ao` subdevice pointer variable will be `NULL`.  In that
case, the following call near the end of the interrupt handler results
in a null pointer dereference:

	comedi_handle_events(dev, s_ao);

Fix it by only calling the above function if `s_ao` is valid.

(There are other uses of `s_ao` by the interrupt handler that may or may
not be reached depending on values of hardware registers.  Trust that
they are reliable for now.)

Note:
commit 4f6f009b204f ("staging: comedi: dt282x: use comedi_handle_events()")
propagates an earlier error from
commit f21c74fa4cfe ("staging: comedi: dt282x: use cfc_handle_events()").

Fixes: 4f6f009b204f ("staging: comedi: dt282x: use comedi_handle_events()")
Cc: &lt;stable@vger.kernel.org&gt; # v3.19+
Signed-off-by: Ian Abbott &lt;abbotti@mev.co.uk&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>staging: comedi: ni_usb6501: Fix possible double-free of -&gt;usb_rx_buf</title>
<updated>2019-04-27T07:36:36+00:00</updated>
<author>
<name>Ian Abbott</name>
<email>abbotti@mev.co.uk</email>
</author>
<published>2019-04-15T11:43:02+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=4e78a1fb8d1d0948aafac07465779e821d9dda2e'/>
<id>urn:sha1:4e78a1fb8d1d0948aafac07465779e821d9dda2e</id>
<content type='text'>
commit af4b54a2e5ba18259ff9aac445bf546dd60d037e upstream.

`ni6501_alloc_usb_buffers()` is called from `ni6501_auto_attach()` to
allocate RX and TX buffers for USB transfers.  It allocates
`devpriv-&gt;usb_rx_buf` followed by `devpriv-&gt;usb_tx_buf`.  If the
allocation of `devpriv-&gt;usb_tx_buf` fails, it frees
`devpriv-&gt;usb_rx_buf`, leaving the pointer set dangling, and returns an
error.  Later, `ni6501_detach()` will be called from the core comedi
module code to clean up.  `ni6501_detach()` also frees both
`devpriv-&gt;usb_rx_buf` and `devpriv-&gt;usb_tx_buf`, but
`devpriv-&gt;usb_rx_buf` may have already beed freed, leading to a
double-free error.  Fix it bu removing the call to
`kfree(devpriv-&gt;usb_rx_buf)` from `ni6501_alloc_usb_buffers()`, relying
on `ni6501_detach()` to free the memory.

Signed-off-by: Ian Abbott &lt;abbotti@mev.co.uk&gt;
Cc: stable &lt;stable@vger.kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>staging: comedi: ni_usb6501: Fix use of uninitialized mutex</title>
<updated>2019-04-27T07:36:35+00:00</updated>
<author>
<name>Ian Abbott</name>
<email>abbotti@mev.co.uk</email>
</author>
<published>2019-04-15T11:43:01+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=09f9bacae11874c6abe368fab7b093dd33ef11ea'/>
<id>urn:sha1:09f9bacae11874c6abe368fab7b093dd33ef11ea</id>
<content type='text'>
commit 660cf4ce9d0f3497cc7456eaa6d74c8b71d6282c upstream.

If `ni6501_auto_attach()` returns an error, the core comedi module code
will call `ni6501_detach()` to clean up.  If `ni6501_auto_attach()`
successfully allocated the comedi device private data, `ni6501_detach()`
assumes that a `struct mutex mut` contained in the private data has been
initialized and uses it.  Unfortunately, there are a couple of places
where `ni6501_auto_attach()` can return an error after allocating the
device private data but before initializing the mutex, so this
assumption is invalid.  Fix it by initializing the mutex just after
allocating the private data in `ni6501_auto_attach()` before any other
errors can be retturned.  Also move the call to `usb_set_intfdata()`
just to keep the code a bit neater (either position for the call is
fine).

I believe this was the cause of the following syzbot crash report
&lt;https://syzkaller.appspot.com/bug?extid=cf4f2b6c24aff0a3edf6&gt;:

usb 1-1: New USB device strings: Mfr=0, Product=0, SerialNumber=0
usb 1-1: config 0 descriptor??
usb 1-1: string descriptor 0 read error: -71
comedi comedi0: Wrong number of endpoints
ni6501 1-1:0.233: driver 'ni6501' failed to auto-configure device.
INFO: trying to register non-static key.
the code is fine but needs lockdep annotation.
turning off the locking correctness validator.
CPU: 0 PID: 585 Comm: kworker/0:3 Not tainted 5.1.0-rc4-319354-g9a33b36 #3
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: usb_hub_wq hub_event
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0xe8/0x16e lib/dump_stack.c:113
 assign_lock_key kernel/locking/lockdep.c:786 [inline]
 register_lock_class+0x11b8/0x1250 kernel/locking/lockdep.c:1095
 __lock_acquire+0xfb/0x37c0 kernel/locking/lockdep.c:3582
 lock_acquire+0x10d/0x2f0 kernel/locking/lockdep.c:4211
 __mutex_lock_common kernel/locking/mutex.c:925 [inline]
 __mutex_lock+0xfe/0x12b0 kernel/locking/mutex.c:1072
 ni6501_detach+0x5b/0x110 drivers/staging/comedi/drivers/ni_usb6501.c:567
 comedi_device_detach+0xed/0x800 drivers/staging/comedi/drivers.c:204
 comedi_device_cleanup.part.0+0x68/0x140 drivers/staging/comedi/comedi_fops.c:156
 comedi_device_cleanup drivers/staging/comedi/comedi_fops.c:187 [inline]
 comedi_free_board_dev.part.0+0x16/0x90 drivers/staging/comedi/comedi_fops.c:190
 comedi_free_board_dev drivers/staging/comedi/comedi_fops.c:189 [inline]
 comedi_release_hardware_device+0x111/0x140 drivers/staging/comedi/comedi_fops.c:2880
 comedi_auto_config.cold+0x124/0x1b0 drivers/staging/comedi/drivers.c:1068
 usb_probe_interface+0x31d/0x820 drivers/usb/core/driver.c:361
 really_probe+0x2da/0xb10 drivers/base/dd.c:509
 driver_probe_device+0x21d/0x350 drivers/base/dd.c:671
 __device_attach_driver+0x1d8/0x290 drivers/base/dd.c:778
 bus_for_each_drv+0x163/0x1e0 drivers/base/bus.c:454
 __device_attach+0x223/0x3a0 drivers/base/dd.c:844
 bus_probe_device+0x1f1/0x2a0 drivers/base/bus.c:514
 device_add+0xad2/0x16e0 drivers/base/core.c:2106
 usb_set_configuration+0xdf7/0x1740 drivers/usb/core/message.c:2021
 generic_probe+0xa2/0xda drivers/usb/core/generic.c:210
 usb_probe_device+0xc0/0x150 drivers/usb/core/driver.c:266
 really_probe+0x2da/0xb10 drivers/base/dd.c:509
 driver_probe_device+0x21d/0x350 drivers/base/dd.c:671
 __device_attach_driver+0x1d8/0x290 drivers/base/dd.c:778
 bus_for_each_drv+0x163/0x1e0 drivers/base/bus.c:454
 __device_attach+0x223/0x3a0 drivers/base/dd.c:844
 bus_probe_device+0x1f1/0x2a0 drivers/base/bus.c:514
 device_add+0xad2/0x16e0 drivers/base/core.c:2106
 usb_new_device.cold+0x537/0xccf drivers/usb/core/hub.c:2534
 hub_port_connect drivers/usb/core/hub.c:5089 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5204 [inline]
 port_event drivers/usb/core/hub.c:5350 [inline]
 hub_event+0x138e/0x3b00 drivers/usb/core/hub.c:5432
 process_one_work+0x90f/0x1580 kernel/workqueue.c:2269
 worker_thread+0x9b/0xe20 kernel/workqueue.c:2415
 kthread+0x313/0x420 kernel/kthread.c:253
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352

Reported-by: syzbot+cf4f2b6c24aff0a3edf6@syzkaller.appspotmail.com
Signed-off-by: Ian Abbott &lt;abbotti@mev.co.uk&gt;
Cc: stable &lt;stable@vger.kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>staging: comedi: vmk80xx: Fix possible double-free of -&gt;usb_rx_buf</title>
<updated>2019-04-27T07:36:35+00:00</updated>
<author>
<name>Ian Abbott</name>
<email>abbotti@mev.co.uk</email>
</author>
<published>2019-04-15T11:52:30+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=edf2f548baa959e90f1a2f0fce737e18701070d5'/>
<id>urn:sha1:edf2f548baa959e90f1a2f0fce737e18701070d5</id>
<content type='text'>
commit 663d294b4768bfd89e529e069bffa544a830b5bf upstream.

`vmk80xx_alloc_usb_buffers()` is called from `vmk80xx_auto_attach()` to
allocate RX and TX buffers for USB transfers.  It allocates
`devpriv-&gt;usb_rx_buf` followed by `devpriv-&gt;usb_tx_buf`.  If the
allocation of `devpriv-&gt;usb_tx_buf` fails, it frees
`devpriv-&gt;usb_rx_buf`,  leaving the pointer set dangling, and returns an
error.  Later, `vmk80xx_detach()` will be called from the core comedi
module code to clean up.  `vmk80xx_detach()` also frees both
`devpriv-&gt;usb_rx_buf` and `devpriv-&gt;usb_tx_buf`, but
`devpriv-&gt;usb_rx_buf` may have already been freed, leading to a
double-free error.  Fix it by removing the call to
`kfree(devpriv-&gt;usb_rx_buf)` from `vmk80xx_alloc_usb_buffers()`, relying
on `vmk80xx_detach()` to free the memory.

Signed-off-by: Ian Abbott &lt;abbotti@mev.co.uk&gt;
Cc: stable &lt;stable@vger.kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>staging: comedi: vmk80xx: Fix use of uninitialized semaphore</title>
<updated>2019-04-27T07:36:35+00:00</updated>
<author>
<name>Ian Abbott</name>
<email>abbotti@mev.co.uk</email>
</author>
<published>2019-04-15T11:10:14+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=1f01a970b8c2de057c7c1cf3afce3d116fb6645b'/>
<id>urn:sha1:1f01a970b8c2de057c7c1cf3afce3d116fb6645b</id>
<content type='text'>
commit 08b7c2f9208f0e2a32159e4e7a4831b7adb10a3e upstream.

If `vmk80xx_auto_attach()` returns an error, the core comedi module code
will call `vmk80xx_detach()` to clean up.  If `vmk80xx_auto_attach()`
successfully allocated the comedi device private data,
`vmk80xx_detach()` assumes that a `struct semaphore limit_sem` contained
in the private data has been initialized and uses it.  Unfortunately,
there are a couple of places where `vmk80xx_auto_attach()` can return an
error after allocating the device private data but before initializing
the semaphore, so this assumption is invalid.  Fix it by initializing
the semaphore just after allocating the private data in
`vmk80xx_auto_attach()` before any other errors can be returned.

I believe this was the cause of the following syzbot crash report
&lt;https://syzkaller.appspot.com/bug?extid=54c2f58f15fe6876b6ad&gt;:

usb 1-1: config 0 has no interface number 0
usb 1-1: New USB device found, idVendor=10cf, idProduct=8068, bcdDevice=e6.8d
usb 1-1: New USB device strings: Mfr=0, Product=0, SerialNumber=0
usb 1-1: config 0 descriptor??
vmk80xx 1-1:0.117: driver 'vmk80xx' failed to auto-configure device.
INFO: trying to register non-static key.
the code is fine but needs lockdep annotation.
turning off the locking correctness validator.
CPU: 0 PID: 12 Comm: kworker/0:1 Not tainted 5.1.0-rc4-319354-g9a33b36 #3
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: usb_hub_wq hub_event
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0xe8/0x16e lib/dump_stack.c:113
 assign_lock_key kernel/locking/lockdep.c:786 [inline]
 register_lock_class+0x11b8/0x1250 kernel/locking/lockdep.c:1095
 __lock_acquire+0xfb/0x37c0 kernel/locking/lockdep.c:3582
 lock_acquire+0x10d/0x2f0 kernel/locking/lockdep.c:4211
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
 _raw_spin_lock_irqsave+0x44/0x60 kernel/locking/spinlock.c:152
 down+0x12/0x80 kernel/locking/semaphore.c:58
 vmk80xx_detach+0x59/0x100 drivers/staging/comedi/drivers/vmk80xx.c:829
 comedi_device_detach+0xed/0x800 drivers/staging/comedi/drivers.c:204
 comedi_device_cleanup.part.0+0x68/0x140 drivers/staging/comedi/comedi_fops.c:156
 comedi_device_cleanup drivers/staging/comedi/comedi_fops.c:187 [inline]
 comedi_free_board_dev.part.0+0x16/0x90 drivers/staging/comedi/comedi_fops.c:190
 comedi_free_board_dev drivers/staging/comedi/comedi_fops.c:189 [inline]
 comedi_release_hardware_device+0x111/0x140 drivers/staging/comedi/comedi_fops.c:2880
 comedi_auto_config.cold+0x124/0x1b0 drivers/staging/comedi/drivers.c:1068
 usb_probe_interface+0x31d/0x820 drivers/usb/core/driver.c:361
 really_probe+0x2da/0xb10 drivers/base/dd.c:509
 driver_probe_device+0x21d/0x350 drivers/base/dd.c:671
 __device_attach_driver+0x1d8/0x290 drivers/base/dd.c:778
 bus_for_each_drv+0x163/0x1e0 drivers/base/bus.c:454
 __device_attach+0x223/0x3a0 drivers/base/dd.c:844
 bus_probe_device+0x1f1/0x2a0 drivers/base/bus.c:514
 device_add+0xad2/0x16e0 drivers/base/core.c:2106
 usb_set_configuration+0xdf7/0x1740 drivers/usb/core/message.c:2021
 generic_probe+0xa2/0xda drivers/usb/core/generic.c:210
 usb_probe_device+0xc0/0x150 drivers/usb/core/driver.c:266
 really_probe+0x2da/0xb10 drivers/base/dd.c:509
 driver_probe_device+0x21d/0x350 drivers/base/dd.c:671
 __device_attach_driver+0x1d8/0x290 drivers/base/dd.c:778
 bus_for_each_drv+0x163/0x1e0 drivers/base/bus.c:454
 __device_attach+0x223/0x3a0 drivers/base/dd.c:844
 bus_probe_device+0x1f1/0x2a0 drivers/base/bus.c:514
 device_add+0xad2/0x16e0 drivers/base/core.c:2106
 usb_new_device.cold+0x537/0xccf drivers/usb/core/hub.c:2534
 hub_port_connect drivers/usb/core/hub.c:5089 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5204 [inline]
 port_event drivers/usb/core/hub.c:5350 [inline]
 hub_event+0x138e/0x3b00 drivers/usb/core/hub.c:5432
 process_one_work+0x90f/0x1580 kernel/workqueue.c:2269
 worker_thread+0x9b/0xe20 kernel/workqueue.c:2415
 kthread+0x313/0x420 kernel/kthread.c:253
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352

Reported-by: syzbot+54c2f58f15fe6876b6ad@syzkaller.appspotmail.com
Signed-off-by: Ian Abbott &lt;abbotti@mev.co.uk&gt;
Cc: stable &lt;stable@vger.kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>staging: comedi: ni_mio_common: Fix divide-by-zero for DIO cmdtest</title>
<updated>2019-04-03T04:26:24+00:00</updated>
<author>
<name>Ian Abbott</name>
<email>abbotti@mev.co.uk</email>
</author>
<published>2019-03-04T14:33:54+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=d0360bf48143539178e0196f8ee1f378e3586136'/>
<id>urn:sha1:d0360bf48143539178e0196f8ee1f378e3586136</id>
<content type='text'>
commit bafd9c64056cd034a1174dcadb65cd3b294ff8f6 upstream.

`ni_cdio_cmdtest()` validates Comedi asynchronous commands for the DIO
subdevice (subdevice 2) of supported National Instruments M-series
cards.  It is called when handling the `COMEDI_CMD` and `COMEDI_CMDTEST`
ioctls for this subdevice.  There are two causes for a possible
divide-by-zero error when validating that the `stop_arg` member of the
passed-in command is not too large.

The first cause for the divide-by-zero is that calls to
`comedi_bytes_per_scan()` are only valid once the command has been
copied to `s-&gt;async-&gt;cmd`, but that copy is only done for the
`COMEDI_CMD` ioctl.  For the `COMEDI_CMDTEST` ioctl, it will use
whatever was left there by the previous `COMEDI_CMD` ioctl, if any.
(This is very likely, as it is usual for the application to use
`COMEDI_CMDTEST` before `COMEDI_CMD`.) If there has been no previous,
valid `COMEDI_CMD` for this subdevice, then `comedi_bytes_per_scan()`
will return 0, so the subsequent division in `ni_cdio_cmdtest()` of
`s-&gt;async-&gt;prealloc_bufsz / comedi_bytes_per_scan(s)` will be a
divide-by-zero error.  To fix this error, call a new function
`comedi_bytes_per_scan_cmd(s, cmd)`, based on the existing
`comedi_bytes_per_scan(s)` but using a specified `struct comedi_cmd` for
its calculations.  (Also refactor `comedi_bytes_per_scan()` to call the
new function.)

Once the first cause for the divide-by-zero has been fixed, the second
cause is that `comedi_bytes_per_scan_cmd()` can legitimately return 0 if
the `scan_end_arg` member of the `struct comedi_cmd` being tested is 0.
Fix it by only performing the division (and validating that `stop_arg`
is no more than the maximum value) if `comedi_bytes_per_scan_cmd()`
returns a non-zero value.

The problem was reported on the COMEDI mailing list here:
https://groups.google.com/forum/#!topic/comedi_list/4t9WlHzMhKM

Reported-by: Ivan Vasilyev &lt;grabesstimme@gmail.com&gt;
Tested-by: Ivan Vasilyev &lt;grabesstimme@gmail.com&gt;
Fixes: f164cbf98fa8 ("staging: comedi: ni_mio_common: add finite regeneration to dio output")
Cc: &lt;stable@vger.kernel.org&gt; # 4.6+
Cc: Spencer E. Olson &lt;olsonse@umich.edu&gt;
Signed-off-by: Ian Abbott &lt;abbotti@mev.co.uk&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>staging: comedi: ni_660x: fix missing break in switch statement</title>
<updated>2019-03-10T06:17:16+00:00</updated>
<author>
<name>Gustavo A. R. Silva</name>
<email>gustavo@embeddedor.com</email>
</author>
<published>2019-02-12T18:44:50+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=63efda29f359591c43d52cc4a3e86b7f693e2269'/>
<id>urn:sha1:63efda29f359591c43d52cc4a3e86b7f693e2269</id>
<content type='text'>
commit 479826cc86118e0d87e5cefb3df5b748e0480924 upstream.

Add missing break statement in order to prevent the code from falling
through to the default case and return -EINVAL every time.

This bug was found thanks to the ongoing efforts to enable
-Wimplicit-fallthrough.

Fixes: aa94f2888825 ("staging: comedi: ni_660x: tidy up ni_660x_set_pfi_routing()")
Cc: stable@vger.kernel.org
Signed-off-by: Gustavo A. R. Silva &lt;gustavo@embeddedor.com&gt;
Reviewed-by: Ian Abbott &lt;abbotti@mev.co.uk&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
</feed>
