<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/drivers/usb/class, branch v4.19.321</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>cdc-acm: Add DISABLE_ECHO quirk for GE HealthCare UI Controller</title>
<updated>2024-09-04T11:13:09+00:00</updated>
<author>
<name>Ian Ray</name>
<email>ian.ray@gehealthcare.com</email>
</author>
<published>2024-08-14T07:29:05+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=43f8d47eaa36c16eb0beafdedbfba51220b4fe69'/>
<id>43f8d47eaa36c16eb0beafdedbfba51220b4fe69</id>
<content type='text'>
commit 0b00583ecacb0b51712a5ecd34cf7e6684307c67 upstream.

USB_DEVICE(0x1901, 0x0006) may send data before cdc_acm is ready, which
may be misinterpreted in the default N_TTY line discipline.

Signed-off-by: Ian Ray &lt;ian.ray@gehealthcare.com&gt;
Acked-by: Oliver Neuku &lt;oneukum@suse.com&gt;
Cc: stable &lt;stable@kernel.org&gt;
Link: https://lore.kernel.org/r/20240814072905.2501-1-ian.ray@gehealthcare.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 0b00583ecacb0b51712a5ecd34cf7e6684307c67 upstream.

USB_DEVICE(0x1901, 0x0006) may send data before cdc_acm is ready, which
may be misinterpreted in the default N_TTY line discipline.

Signed-off-by: Ian Ray &lt;ian.ray@gehealthcare.com&gt;
Acked-by: Oliver Neuku &lt;oneukum@suse.com&gt;
Cc: stable &lt;stable@kernel.org&gt;
Link: https://lore.kernel.org/r/20240814072905.2501-1-ian.ray@gehealthcare.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>USB: class: cdc-wdm: Fix CPU lockup caused by excessive log messages</title>
<updated>2024-07-05T07:00:22+00:00</updated>
<author>
<name>Alan Stern</name>
<email>stern@rowland.harvard.edu</email>
</author>
<published>2024-06-14T01:30:43+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=217d1f44fff560b3995a685a60aa66e55a7f0f56'/>
<id>217d1f44fff560b3995a685a60aa66e55a7f0f56</id>
<content type='text'>
commit 22f00812862564b314784167a89f27b444f82a46 upstream.

The syzbot fuzzer found that the interrupt-URB completion callback in
the cdc-wdm driver was taking too long, and the driver's immediate
resubmission of interrupt URBs with -EPROTO status combined with the
dummy-hcd emulation to cause a CPU lockup:

cdc_wdm 1-1:1.0: nonzero urb status received: -71
cdc_wdm 1-1:1.0: wdm_int_callback - 0 bytes
watchdog: BUG: soft lockup - CPU#0 stuck for 26s! [syz-executor782:6625]
CPU#0 Utilization every 4s during lockup:
	#1:  98% system,	  0% softirq,	  3% hardirq,	  0% idle
	#2:  98% system,	  0% softirq,	  3% hardirq,	  0% idle
	#3:  98% system,	  0% softirq,	  3% hardirq,	  0% idle
	#4:  98% system,	  0% softirq,	  3% hardirq,	  0% idle
	#5:  98% system,	  1% softirq,	  3% hardirq,	  0% idle
Modules linked in:
irq event stamp: 73096
hardirqs last  enabled at (73095): [&lt;ffff80008037bc00&gt;] console_emit_next_record kernel/printk/printk.c:2935 [inline]
hardirqs last  enabled at (73095): [&lt;ffff80008037bc00&gt;] console_flush_all+0x650/0xb74 kernel/printk/printk.c:2994
hardirqs last disabled at (73096): [&lt;ffff80008af10b00&gt;] __el1_irq arch/arm64/kernel/entry-common.c:533 [inline]
hardirqs last disabled at (73096): [&lt;ffff80008af10b00&gt;] el1_interrupt+0x24/0x68 arch/arm64/kernel/entry-common.c:551
softirqs last  enabled at (73048): [&lt;ffff8000801ea530&gt;] softirq_handle_end kernel/softirq.c:400 [inline]
softirqs last  enabled at (73048): [&lt;ffff8000801ea530&gt;] handle_softirqs+0xa60/0xc34 kernel/softirq.c:582
softirqs last disabled at (73043): [&lt;ffff800080020de8&gt;] __do_softirq+0x14/0x20 kernel/softirq.c:588
CPU: 0 PID: 6625 Comm: syz-executor782 Tainted: G        W          6.10.0-rc2-syzkaller-g8867bbd4a056 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024

Testing showed that the problem did not occur if the two error
messages -- the first two lines above -- were removed; apparently adding
material to the kernel log takes a surprisingly large amount of time.

In any case, the best approach for preventing these lockups and to
avoid spamming the log with thousands of error messages per second is
to ratelimit the two dev_err() calls.  Therefore we replace them with
dev_err_ratelimited().

Signed-off-by: Alan Stern &lt;stern@rowland.harvard.edu&gt;
Suggested-by: Greg KH &lt;gregkh@linuxfoundation.org&gt;
Reported-and-tested-by: syzbot+5f996b83575ef4058638@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/linux-usb/00000000000073d54b061a6a1c65@google.com/
Reported-and-tested-by: syzbot+1b2abad17596ad03dcff@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/linux-usb/000000000000f45085061aa9b37e@google.com/
Fixes: 9908a32e94de ("USB: remove err() macro from usb class drivers")
Link: https://lore.kernel.org/linux-usb/40dfa45b-5f21-4eef-a8c1-51a2f320e267@rowland.harvard.edu/
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/29855215-52f5-4385-b058-91f42c2bee18@rowland.harvard.edu
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 22f00812862564b314784167a89f27b444f82a46 upstream.

The syzbot fuzzer found that the interrupt-URB completion callback in
the cdc-wdm driver was taking too long, and the driver's immediate
resubmission of interrupt URBs with -EPROTO status combined with the
dummy-hcd emulation to cause a CPU lockup:

cdc_wdm 1-1:1.0: nonzero urb status received: -71
cdc_wdm 1-1:1.0: wdm_int_callback - 0 bytes
watchdog: BUG: soft lockup - CPU#0 stuck for 26s! [syz-executor782:6625]
CPU#0 Utilization every 4s during lockup:
	#1:  98% system,	  0% softirq,	  3% hardirq,	  0% idle
	#2:  98% system,	  0% softirq,	  3% hardirq,	  0% idle
	#3:  98% system,	  0% softirq,	  3% hardirq,	  0% idle
	#4:  98% system,	  0% softirq,	  3% hardirq,	  0% idle
	#5:  98% system,	  1% softirq,	  3% hardirq,	  0% idle
Modules linked in:
irq event stamp: 73096
hardirqs last  enabled at (73095): [&lt;ffff80008037bc00&gt;] console_emit_next_record kernel/printk/printk.c:2935 [inline]
hardirqs last  enabled at (73095): [&lt;ffff80008037bc00&gt;] console_flush_all+0x650/0xb74 kernel/printk/printk.c:2994
hardirqs last disabled at (73096): [&lt;ffff80008af10b00&gt;] __el1_irq arch/arm64/kernel/entry-common.c:533 [inline]
hardirqs last disabled at (73096): [&lt;ffff80008af10b00&gt;] el1_interrupt+0x24/0x68 arch/arm64/kernel/entry-common.c:551
softirqs last  enabled at (73048): [&lt;ffff8000801ea530&gt;] softirq_handle_end kernel/softirq.c:400 [inline]
softirqs last  enabled at (73048): [&lt;ffff8000801ea530&gt;] handle_softirqs+0xa60/0xc34 kernel/softirq.c:582
softirqs last disabled at (73043): [&lt;ffff800080020de8&gt;] __do_softirq+0x14/0x20 kernel/softirq.c:588
CPU: 0 PID: 6625 Comm: syz-executor782 Tainted: G        W          6.10.0-rc2-syzkaller-g8867bbd4a056 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024

Testing showed that the problem did not occur if the two error
messages -- the first two lines above -- were removed; apparently adding
material to the kernel log takes a surprisingly large amount of time.

In any case, the best approach for preventing these lockups and to
avoid spamming the log with thousands of error messages per second is
to ratelimit the two dev_err() calls.  Therefore we replace them with
dev_err_ratelimited().

Signed-off-by: Alan Stern &lt;stern@rowland.harvard.edu&gt;
Suggested-by: Greg KH &lt;gregkh@linuxfoundation.org&gt;
Reported-and-tested-by: syzbot+5f996b83575ef4058638@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/linux-usb/00000000000073d54b061a6a1c65@google.com/
Reported-and-tested-by: syzbot+1b2abad17596ad03dcff@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/linux-usb/000000000000f45085061aa9b37e@google.com/
Fixes: 9908a32e94de ("USB: remove err() macro from usb class drivers")
Link: https://lore.kernel.org/linux-usb/40dfa45b-5f21-4eef-a8c1-51a2f320e267@rowland.harvard.edu/
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/29855215-52f5-4385-b058-91f42c2bee18@rowland.harvard.edu
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Revert "usb: cdc-wdm: close race between read and workqueue"</title>
<updated>2024-05-02T14:17:10+00:00</updated>
<author>
<name>Greg Kroah-Hartman</name>
<email>gregkh@linuxfoundation.org</email>
</author>
<published>2024-04-18T14:33:28+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=347cca11bb78b9f3c29b45a9c52e70258bd008bf'/>
<id>347cca11bb78b9f3c29b45a9c52e70258bd008bf</id>
<content type='text'>
commit 1607830dadeefc407e4956336d9fcd9e9defd810 upstream.

This reverts commit 339f83612f3a569b194680768b22bf113c26a29d.

It has been found to cause problems in a number of Chromebook devices,
so revert the change until it can be brought back in a safe way.

Link: https://lore.kernel.org/r/385a3519-b45d-48c5-a6fd-a3fdb6bec92f@chromium.org
Reported-by:: Aleksander Morgado &lt;aleksandermj@chromium.org&gt;
Fixes: 339f83612f3a ("usb: cdc-wdm: close race between read and workqueue")
Cc: stable &lt;stable@kernel.org&gt;
Cc: Oliver Neukum &lt;oneukum@suse.com&gt;
Cc: Bjørn Mork &lt;bjorn@mork.no&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 1607830dadeefc407e4956336d9fcd9e9defd810 upstream.

This reverts commit 339f83612f3a569b194680768b22bf113c26a29d.

It has been found to cause problems in a number of Chromebook devices,
so revert the change until it can be brought back in a safe way.

Link: https://lore.kernel.org/r/385a3519-b45d-48c5-a6fd-a3fdb6bec92f@chromium.org
Reported-by:: Aleksander Morgado &lt;aleksandermj@chromium.org&gt;
Fixes: 339f83612f3a ("usb: cdc-wdm: close race between read and workqueue")
Cc: stable &lt;stable@kernel.org&gt;
Cc: Oliver Neukum &lt;oneukum@suse.com&gt;
Cc: Bjørn Mork &lt;bjorn@mork.no&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>usb: cdc-wdm: close race between read and workqueue</title>
<updated>2024-04-13T10:50:09+00:00</updated>
<author>
<name>Oliver Neukum</name>
<email>oneukum@suse.com</email>
</author>
<published>2024-03-14T11:50:48+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=5904411219601127ffdbd2d622bb5d67f9d8d16c'/>
<id>5904411219601127ffdbd2d622bb5d67f9d8d16c</id>
<content type='text'>
commit 339f83612f3a569b194680768b22bf113c26a29d upstream.

wdm_read() cannot race with itself. However, in
service_outstanding_interrupt() it can race with the
workqueue, which can be triggered by error handling.

Hence we need to make sure that the WDM_RESPONDING
flag is not just only set but tested.

Fixes: afba937e540c9 ("USB: CDC WDM driver")
Cc: stable &lt;stable@kernel.org&gt;
Signed-off-by: Oliver Neukum &lt;oneukum@suse.com&gt;
Link: https://lore.kernel.org/r/20240314115132.3907-1-oneukum@suse.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 339f83612f3a569b194680768b22bf113c26a29d upstream.

wdm_read() cannot race with itself. However, in
service_outstanding_interrupt() it can race with the
workqueue, which can be triggered by error handling.

Hence we need to make sure that the WDM_RESPONDING
flag is not just only set but tested.

Fixes: afba937e540c9 ("USB: CDC WDM driver")
Cc: stable &lt;stable@kernel.org&gt;
Signed-off-by: Oliver Neukum &lt;oneukum@suse.com&gt;
Link: https://lore.kernel.org/r/20240314115132.3907-1-oneukum@suse.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>USB: cdc-acm: Add Icom PMR F3400 support (0c26:0020)</title>
<updated>2022-09-15T10:17:04+00:00</updated>
<author>
<name>Thierry GUIBERT</name>
<email>thierry.guibert@croix-rouge.fr</email>
</author>
<published>2022-08-19T08:17:02+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=cb9ec6cecb9867769ea39da3ebc19839ca68edb1'/>
<id>cb9ec6cecb9867769ea39da3ebc19839ca68edb1</id>
<content type='text'>
commit a10bc71729b236fe36de0d8e4d35c959fd8dec3a upstream.

Supports for ICOM F3400 and ICOM F4400 PMR radios in CDC-ACM driver
enabling the AT serial port.
The Vendor Id is 0x0C26
The Product ID is 0x0020

Output of lsusb :
Bus 001 Device 009: ID 0c26:0020 Prolific Technology Inc. ICOM Radio
Couldn't open device, some information will be missing
Device Descriptor:
  bLength                18
  bDescriptorType         1
  bcdUSB               2.00
  bDeviceClass            2 Communications
  bDeviceSubClass         0
  bDeviceProtocol         0
  bMaxPacketSize0        64
  idVendor           0x0c26 Prolific Technology Inc.
  idProduct          0x0020
  bcdDevice            0.00
  iManufacturer           1 ICOM Inc.
  iProduct                2 ICOM Radio
  iSerial                 3 *obfuscated*
  bNumConfigurations      1
  Configuration Descriptor:
    bLength                 9
    bDescriptorType         2
    wTotalLength       0x0030
    bNumInterfaces          2
    bConfigurationValue     1
    iConfiguration          0
    bmAttributes         0xc0
      Self Powered
    MaxPower                0mA
    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        0
      bAlternateSetting       0
      bNumEndpoints           1
      bInterfaceClass         2 Communications
      bInterfaceSubClass      2 Abstract (modem)
      bInterfaceProtocol      1 AT-commands (v.25ter)
      iInterface              0
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x83  EP 3 IN
        bmAttributes            3
          Transfer Type            Interrupt
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0040  1x 64 bytes
        bInterval              12
    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        1
      bAlternateSetting       0
      bNumEndpoints           2
      bInterfaceClass        10 CDC Data
      bInterfaceSubClass      0
      bInterfaceProtocol      0
      iInterface              0
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x82  EP 2 IN
        bmAttributes            2
          Transfer Type            Bulk
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0200  1x 512 bytes
        bInterval               0
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x02  EP 2 OUT
        bmAttributes            2
          Transfer Type            Bulk
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0200  1x 512 bytes
        bInterval               0

Signed-off-by: Thierry GUIBERT &lt;thierry.guibert@croix-rouge.fr&gt;
Cc: stable &lt;stable@kernel.org&gt;
Link: https://lore.kernel.org/r/20220819081702.84118-1-thierry.guibert@croix-rouge.fr
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit a10bc71729b236fe36de0d8e4d35c959fd8dec3a upstream.

Supports for ICOM F3400 and ICOM F4400 PMR radios in CDC-ACM driver
enabling the AT serial port.
The Vendor Id is 0x0C26
The Product ID is 0x0020

Output of lsusb :
Bus 001 Device 009: ID 0c26:0020 Prolific Technology Inc. ICOM Radio
Couldn't open device, some information will be missing
Device Descriptor:
  bLength                18
  bDescriptorType         1
  bcdUSB               2.00
  bDeviceClass            2 Communications
  bDeviceSubClass         0
  bDeviceProtocol         0
  bMaxPacketSize0        64
  idVendor           0x0c26 Prolific Technology Inc.
  idProduct          0x0020
  bcdDevice            0.00
  iManufacturer           1 ICOM Inc.
  iProduct                2 ICOM Radio
  iSerial                 3 *obfuscated*
  bNumConfigurations      1
  Configuration Descriptor:
    bLength                 9
    bDescriptorType         2
    wTotalLength       0x0030
    bNumInterfaces          2
    bConfigurationValue     1
    iConfiguration          0
    bmAttributes         0xc0
      Self Powered
    MaxPower                0mA
    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        0
      bAlternateSetting       0
      bNumEndpoints           1
      bInterfaceClass         2 Communications
      bInterfaceSubClass      2 Abstract (modem)
      bInterfaceProtocol      1 AT-commands (v.25ter)
      iInterface              0
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x83  EP 3 IN
        bmAttributes            3
          Transfer Type            Interrupt
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0040  1x 64 bytes
        bInterval              12
    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        1
      bAlternateSetting       0
      bNumEndpoints           2
      bInterfaceClass        10 CDC Data
      bInterfaceSubClass      0
      bInterfaceProtocol      0
      iInterface              0
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x82  EP 2 IN
        bmAttributes            2
          Transfer Type            Bulk
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0200  1x 512 bytes
        bInterval               0
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x02  EP 2 OUT
        bmAttributes            2
          Transfer Type            Bulk
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0200  1x 512 bytes
        bInterval               0

Signed-off-by: Thierry GUIBERT &lt;thierry.guibert@croix-rouge.fr&gt;
Cc: stable &lt;stable@kernel.org&gt;
Link: https://lore.kernel.org/r/20220819081702.84118-1-thierry.guibert@croix-rouge.fr
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>usb: cdc-wdm: fix reading stuck on device close</title>
<updated>2022-05-18T07:42:49+00:00</updated>
<author>
<name>Sergey Ryazanov</name>
<email>ryazanov.s.a@gmail.com</email>
</author>
<published>2022-05-01T17:58:28+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=03556d3cd52d63e34d4de2529573ce51d77f7eda'/>
<id>03556d3cd52d63e34d4de2529573ce51d77f7eda</id>
<content type='text'>
commit 01e01f5c89773c600a9f0b32c888de0146066c3a upstream.

cdc-wdm tracks whether a response reading request is in-progress and
blocks the next request from being sent until the previous request is
completed. As soon as last user closes the cdc-wdm device file, the
driver cancels any ongoing requests, resets the pending response
counter, but leaves the response reading in-progress flag
(WDM_RESPONDING) untouched.

So if the user closes the device file during the response receive
request is being performed, no more data will be obtained from the
modem. The request will be cancelled, effectively preventing the
WDM_RESPONDING flag from being reseted. Keeping the flag set will
prevent a new response receive request from being sent, permanently
blocking the read path. The read path will staying blocked until the
module will be reloaded or till the modem will be re-attached.

This stuck has been observed with a Huawei E3372 modem attached to an
OpenWrt router and using the comgt utility to set up a network
connection.

Fix this issue by clearing the WDM_RESPONDING flag on the device file
close.

Without this fix, the device reading stuck can be easily reproduced in a
few connection establishing attempts. With this fix, a load test for
modem connection re-establishing worked for several hours without any
issues.

Fixes: 922a5eadd5a3 ("usb: cdc-wdm: Fix race between autosuspend and reading from the device")
Signed-off-by: Sergey Ryazanov &lt;ryazanov.s.a@gmail.com&gt;
Cc: stable &lt;stable@vger.kernel.org&gt;
Acked-by: Oliver Neukum &lt;oneukum@suse.com&gt;
Link: https://lore.kernel.org/r/20220501175828.8185-1-ryazanov.s.a@gmail.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 01e01f5c89773c600a9f0b32c888de0146066c3a upstream.

cdc-wdm tracks whether a response reading request is in-progress and
blocks the next request from being sent until the previous request is
completed. As soon as last user closes the cdc-wdm device file, the
driver cancels any ongoing requests, resets the pending response
counter, but leaves the response reading in-progress flag
(WDM_RESPONDING) untouched.

So if the user closes the device file during the response receive
request is being performed, no more data will be obtained from the
modem. The request will be cancelled, effectively preventing the
WDM_RESPONDING flag from being reseted. Keeping the flag set will
prevent a new response receive request from being sent, permanently
blocking the read path. The read path will staying blocked until the
module will be reloaded or till the modem will be re-attached.

This stuck has been observed with a Huawei E3372 modem attached to an
OpenWrt router and using the comgt utility to set up a network
connection.

Fix this issue by clearing the WDM_RESPONDING flag on the device file
close.

Without this fix, the device reading stuck can be easily reproduced in a
few connection establishing attempts. With this fix, a load test for
modem connection re-establishing worked for several hours without any
issues.

Fixes: 922a5eadd5a3 ("usb: cdc-wdm: Fix race between autosuspend and reading from the device")
Signed-off-by: Sergey Ryazanov &lt;ryazanov.s.a@gmail.com&gt;
Cc: stable &lt;stable@vger.kernel.org&gt;
Acked-by: Oliver Neukum &lt;oneukum@suse.com&gt;
Link: https://lore.kernel.org/r/20220501175828.8185-1-ryazanov.s.a@gmail.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>USB: cdc-acm: fix break reporting</title>
<updated>2021-10-13T08:10:50+00:00</updated>
<author>
<name>Johan Hovold</name>
<email>johan@kernel.org</email>
</author>
<published>2021-09-29T09:09:37+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=2cc9bc2342cf63a5ef422b681c96ec8a51ad9c3b'/>
<id>2cc9bc2342cf63a5ef422b681c96ec8a51ad9c3b</id>
<content type='text'>
commit 58fc1daa4d2e9789b9ffc880907c961ea7c062cc upstream.

A recent change that started reporting break events forgot to push the
event to the line discipline, which meant that a detected break would
not be reported until further characters had been receive (the port
could even have been closed and reopened in between).

Fixes: 08dff274edda ("cdc-acm: fix BREAK rx code path adding necessary calls")
Cc: stable@vger.kernel.org
Acked-by: Oliver Neukum &lt;oneukum@suse.com&gt;
Signed-off-by: Johan Hovold &lt;johan@kernel.org&gt;
Link: https://lore.kernel.org/r/20210929090937.7410-3-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 58fc1daa4d2e9789b9ffc880907c961ea7c062cc upstream.

A recent change that started reporting break events forgot to push the
event to the line discipline, which meant that a detected break would
not be reported until further characters had been receive (the port
could even have been closed and reopened in between).

Fixes: 08dff274edda ("cdc-acm: fix BREAK rx code path adding necessary calls")
Cc: stable@vger.kernel.org
Acked-by: Oliver Neukum &lt;oneukum@suse.com&gt;
Signed-off-by: Johan Hovold &lt;johan@kernel.org&gt;
Link: https://lore.kernel.org/r/20210929090937.7410-3-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>USB: cdc-acm: fix racy tty buffer accesses</title>
<updated>2021-10-13T08:10:50+00:00</updated>
<author>
<name>Johan Hovold</name>
<email>johan@kernel.org</email>
</author>
<published>2021-09-29T09:09:36+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=5586e0f68fea90a63f013e3bb0e0f35756489854'/>
<id>5586e0f68fea90a63f013e3bb0e0f35756489854</id>
<content type='text'>
commit 65a205e6113506e69a503b61d97efec43fc10fd7 upstream.

A recent change that started reporting break events to the line
discipline caused the tty-buffer insertions to no longer be serialised
by inserting events also from the completion handler for the interrupt
endpoint.

Completion calls for distinct endpoints are not guaranteed to be
serialised. For example, in case a host-controller driver uses
bottom-half completion, the interrupt and bulk-in completion handlers
can end up running in parallel on two CPUs (high-and low-prio tasklets,
respectively) thereby breaking the tty layer's single producer
assumption.

Fix this by holding the read lock also when inserting characters from
the bulk endpoint.

Fixes: 08dff274edda ("cdc-acm: fix BREAK rx code path adding necessary calls")
Cc: stable@vger.kernel.org
Acked-by: Oliver Neukum &lt;oneukum@suse.com&gt;
Signed-off-by: Johan Hovold &lt;johan@kernel.org&gt;
Link: https://lore.kernel.org/r/20210929090937.7410-2-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 65a205e6113506e69a503b61d97efec43fc10fd7 upstream.

A recent change that started reporting break events to the line
discipline caused the tty-buffer insertions to no longer be serialised
by inserting events also from the completion handler for the interrupt
endpoint.

Completion calls for distinct endpoints are not guaranteed to be
serialised. For example, in case a host-controller driver uses
bottom-half completion, the interrupt and bulk-in completion handlers
can end up running in parallel on two CPUs (high-and low-prio tasklets,
respectively) thereby breaking the tty layer's single producer
assumption.

Fix this by holding the read lock also when inserting characters from
the bulk endpoint.

Fixes: 08dff274edda ("cdc-acm: fix BREAK rx code path adding necessary calls")
Cc: stable@vger.kernel.org
Acked-by: Oliver Neukum &lt;oneukum@suse.com&gt;
Signed-off-by: Johan Hovold &lt;johan@kernel.org&gt;
Link: https://lore.kernel.org/r/20210929090937.7410-2-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>USB: cdc-acm: fix minor-number release</title>
<updated>2021-10-06T13:31:11+00:00</updated>
<author>
<name>Johan Hovold</name>
<email>johan@kernel.org</email>
</author>
<published>2021-09-07T08:23:18+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=0c30a2b7c144dee1a2a6f33073a2266039304968'/>
<id>0c30a2b7c144dee1a2a6f33073a2266039304968</id>
<content type='text'>
commit 91fac0741d4817945c6ee0a17591421e7f5ecb86 upstream.

If the driver runs out of minor numbers it would release minor 0 and
allow another device to claim the minor while still in use.

Fortunately, registering the tty class device of the second device would
fail (with a stack dump) due to the sysfs name collision so no memory is
leaked.

Fixes: cae2bc768d17 ("usb: cdc-acm: Decrement tty port's refcount if probe() fail")
Cc: stable@vger.kernel.org      # 4.19
Cc: Jaejoong Kim &lt;climbbb.kim@gmail.com&gt;
Acked-by: Oliver Neukum &lt;oneukum@suse.com&gt;
Signed-off-by: Johan Hovold &lt;johan@kernel.org&gt;
Link: https://lore.kernel.org/r/20210907082318.7757-1-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 91fac0741d4817945c6ee0a17591421e7f5ecb86 upstream.

If the driver runs out of minor numbers it would release minor 0 and
allow another device to claim the minor while still in use.

Fortunately, registering the tty class device of the second device would
fail (with a stack dump) due to the sysfs name collision so no memory is
leaked.

Fixes: cae2bc768d17 ("usb: cdc-acm: Decrement tty port's refcount if probe() fail")
Cc: stable@vger.kernel.org      # 4.19
Cc: Jaejoong Kim &lt;climbbb.kim@gmail.com&gt;
Acked-by: Oliver Neukum &lt;oneukum@suse.com&gt;
Signed-off-by: Johan Hovold &lt;johan@kernel.org&gt;
Link: https://lore.kernel.org/r/20210907082318.7757-1-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>USB: usbtmc: Fix RCU stall warning</title>
<updated>2021-08-12T11:19:41+00:00</updated>
<author>
<name>Qiang.zhang</name>
<email>qiang.zhang@windriver.com</email>
</author>
<published>2021-07-23T00:43:34+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=08433a2b5b0d3975feac4c6b50b02e8c47b74948'/>
<id>08433a2b5b0d3975feac4c6b50b02e8c47b74948</id>
<content type='text'>
commit 30fad76ce4e98263edfa8f885c81d5426c1bf169 upstream.

rcu: INFO: rcu_preempt self-detected stall on CPU
rcu:    1-...!: (2 ticks this GP) idle=d92/1/0x4000000000000000
        softirq=25390/25392 fqs=3
        (t=12164 jiffies g=31645 q=43226)
rcu: rcu_preempt kthread starved for 12162 jiffies! g31645 f0x0
     RCU_GP_WAIT_FQS(5) -&gt;state=0x0 -&gt;cpu=0
rcu:    Unless rcu_preempt kthread gets sufficient CPU time,
        OOM is now expected behavior.
rcu: RCU grace-period kthread stack dump:
task:rcu_preempt     state:R  running task
...........
usbtmc 3-1:0.0: unknown status received: -71
usbtmc 3-1:0.0: unknown status received: -71
usbtmc 3-1:0.0: unknown status received: -71
usbtmc 3-1:0.0: unknown status received: -71
usbtmc 3-1:0.0: unknown status received: -71
usbtmc 3-1:0.0: unknown status received: -71
usbtmc 3-1:0.0: unknown status received: -71
usbtmc 3-1:0.0: unknown status received: -71
usbtmc 3-1:0.0: usb_submit_urb failed: -19

The function usbtmc_interrupt() resubmits urbs when the error status
of an urb is -EPROTO. In systems using the dummy_hcd usb controller
this can result in endless interrupt loops when the usbtmc device is
disconnected from the host system.

Since host controller drivers already try to recover from transmission
errors, there is no need to resubmit the urb or try other solutions
to repair the error situation.

In case of errors the INT pipe just stops to wait for further packets.

Fixes: dbf3e7f654c0 ("Implement an ioctl to support the USMTMC-USB488 READ_STATUS_BYTE operation")
Cc: stable@vger.kernel.org
Reported-by: syzbot+e2eae5639e7203360018@syzkaller.appspotmail.com
Signed-off-by: Qiang.zhang &lt;qiang.zhang@windriver.com&gt;
Acked-by: Guido Kiener &lt;guido.kiener@rohde-schwarz.com&gt;
Link: https://lore.kernel.org/r/20210723004334.458930-1-qiang.zhang@windriver.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 30fad76ce4e98263edfa8f885c81d5426c1bf169 upstream.

rcu: INFO: rcu_preempt self-detected stall on CPU
rcu:    1-...!: (2 ticks this GP) idle=d92/1/0x4000000000000000
        softirq=25390/25392 fqs=3
        (t=12164 jiffies g=31645 q=43226)
rcu: rcu_preempt kthread starved for 12162 jiffies! g31645 f0x0
     RCU_GP_WAIT_FQS(5) -&gt;state=0x0 -&gt;cpu=0
rcu:    Unless rcu_preempt kthread gets sufficient CPU time,
        OOM is now expected behavior.
rcu: RCU grace-period kthread stack dump:
task:rcu_preempt     state:R  running task
...........
usbtmc 3-1:0.0: unknown status received: -71
usbtmc 3-1:0.0: unknown status received: -71
usbtmc 3-1:0.0: unknown status received: -71
usbtmc 3-1:0.0: unknown status received: -71
usbtmc 3-1:0.0: unknown status received: -71
usbtmc 3-1:0.0: unknown status received: -71
usbtmc 3-1:0.0: unknown status received: -71
usbtmc 3-1:0.0: unknown status received: -71
usbtmc 3-1:0.0: usb_submit_urb failed: -19

The function usbtmc_interrupt() resubmits urbs when the error status
of an urb is -EPROTO. In systems using the dummy_hcd usb controller
this can result in endless interrupt loops when the usbtmc device is
disconnected from the host system.

Since host controller drivers already try to recover from transmission
errors, there is no need to resubmit the urb or try other solutions
to repair the error situation.

In case of errors the INT pipe just stops to wait for further packets.

Fixes: dbf3e7f654c0 ("Implement an ioctl to support the USMTMC-USB488 READ_STATUS_BYTE operation")
Cc: stable@vger.kernel.org
Reported-by: syzbot+e2eae5639e7203360018@syzkaller.appspotmail.com
Signed-off-by: Qiang.zhang &lt;qiang.zhang@windriver.com&gt;
Acked-by: Guido Kiener &lt;guido.kiener@rohde-schwarz.com&gt;
Link: https://lore.kernel.org/r/20210723004334.458930-1-qiang.zhang@windriver.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
