<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/drivers/usb/core, branch linux-3.16.y</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>USB: core: Fix free-while-in-use bug in the USB S-Glibrary</title>
<updated>2020-06-11T18:05:40+00:00</updated>
<author>
<name>Alan Stern</name>
<email>stern@rowland.harvard.edu</email>
</author>
<published>2020-03-28T20:18:11+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=575f200adca1fe48df15063b1a5673a9b5f713bd'/>
<id>575f200adca1fe48df15063b1a5673a9b5f713bd</id>
<content type='text'>
commit 056ad39ee9253873522f6469c3364964a322912b upstream.

FuzzUSB (a variant of syzkaller) found a free-while-still-in-use bug
in the USB scatter-gather library:

BUG: KASAN: use-after-free in atomic_read
include/asm-generic/atomic-instrumented.h:26 [inline]
BUG: KASAN: use-after-free in usb_hcd_unlink_urb+0x5f/0x170
drivers/usb/core/hcd.c:1607
Read of size 4 at addr ffff888065379610 by task kworker/u4:1/27

CPU: 1 PID: 27 Comm: kworker/u4:1 Not tainted 5.5.11 #2
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
1.10.2-1ubuntu1 04/01/2014
Workqueue: scsi_tmf_2 scmd_eh_abort_handler
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0xce/0x128 lib/dump_stack.c:118
 print_address_description.constprop.4+0x21/0x3c0 mm/kasan/report.c:374
 __kasan_report+0x153/0x1cb mm/kasan/report.c:506
 kasan_report+0x12/0x20 mm/kasan/common.c:639
 check_memory_region_inline mm/kasan/generic.c:185 [inline]
 check_memory_region+0x152/0x1b0 mm/kasan/generic.c:192
 __kasan_check_read+0x11/0x20 mm/kasan/common.c:95
 atomic_read include/asm-generic/atomic-instrumented.h:26 [inline]
 usb_hcd_unlink_urb+0x5f/0x170 drivers/usb/core/hcd.c:1607
 usb_unlink_urb+0x72/0xb0 drivers/usb/core/urb.c:657
 usb_sg_cancel+0x14e/0x290 drivers/usb/core/message.c:602
 usb_stor_stop_transport+0x5e/0xa0 drivers/usb/storage/transport.c:937

This bug occurs when cancellation of the S-G transfer races with
transfer completion.  When that happens, usb_sg_cancel() may continue
to access the transfer's URBs after usb_sg_wait() has freed them.

The bug is caused by the fact that usb_sg_cancel() does not take any
sort of reference to the transfer, and so there is nothing to prevent
the URBs from being deallocated while the routine is trying to use
them.  The fix is to take such a reference by incrementing the
transfer's io-&gt;count field while the cancellation is in progres and
decrementing it afterward.  The transfer's URBs are not deallocated
until io-&gt;complete is triggered, which happens when io-&gt;count reaches
zero.

Signed-off-by: Alan Stern &lt;stern@rowland.harvard.edu&gt;
Reported-and-tested-by: Kyungtae Kim &lt;kt0755@gmail.com&gt;
CC: &lt;stable@vger.kernel.org&gt;

Link: https://lore.kernel.org/r/Pine.LNX.4.44L0.2003281615140.14837-100000@netrider.rowland.org
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 056ad39ee9253873522f6469c3364964a322912b upstream.

FuzzUSB (a variant of syzkaller) found a free-while-still-in-use bug
in the USB scatter-gather library:

BUG: KASAN: use-after-free in atomic_read
include/asm-generic/atomic-instrumented.h:26 [inline]
BUG: KASAN: use-after-free in usb_hcd_unlink_urb+0x5f/0x170
drivers/usb/core/hcd.c:1607
Read of size 4 at addr ffff888065379610 by task kworker/u4:1/27

CPU: 1 PID: 27 Comm: kworker/u4:1 Not tainted 5.5.11 #2
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
1.10.2-1ubuntu1 04/01/2014
Workqueue: scsi_tmf_2 scmd_eh_abort_handler
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0xce/0x128 lib/dump_stack.c:118
 print_address_description.constprop.4+0x21/0x3c0 mm/kasan/report.c:374
 __kasan_report+0x153/0x1cb mm/kasan/report.c:506
 kasan_report+0x12/0x20 mm/kasan/common.c:639
 check_memory_region_inline mm/kasan/generic.c:185 [inline]
 check_memory_region+0x152/0x1b0 mm/kasan/generic.c:192
 __kasan_check_read+0x11/0x20 mm/kasan/common.c:95
 atomic_read include/asm-generic/atomic-instrumented.h:26 [inline]
 usb_hcd_unlink_urb+0x5f/0x170 drivers/usb/core/hcd.c:1607
 usb_unlink_urb+0x72/0xb0 drivers/usb/core/urb.c:657
 usb_sg_cancel+0x14e/0x290 drivers/usb/core/message.c:602
 usb_stor_stop_transport+0x5e/0xa0 drivers/usb/storage/transport.c:937

This bug occurs when cancellation of the S-G transfer races with
transfer completion.  When that happens, usb_sg_cancel() may continue
to access the transfer's URBs after usb_sg_wait() has freed them.

The bug is caused by the fact that usb_sg_cancel() does not take any
sort of reference to the transfer, and so there is nothing to prevent
the URBs from being deallocated while the routine is trying to use
them.  The fix is to take such a reference by incrementing the
transfer's io-&gt;count field while the cancellation is in progres and
decrementing it afterward.  The transfer's URBs are not deallocated
until io-&gt;complete is triggered, which happens when io-&gt;count reaches
zero.

Signed-off-by: Alan Stern &lt;stern@rowland.harvard.edu&gt;
Reported-and-tested-by: Kyungtae Kim &lt;kt0755@gmail.com&gt;
CC: &lt;stable@vger.kernel.org&gt;

Link: https://lore.kernel.org/r/Pine.LNX.4.44L0.2003281615140.14837-100000@netrider.rowland.org
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drivers: usb: core: Minimize irq disabling in usb_sg_cancel()</title>
<updated>2020-06-11T18:05:40+00:00</updated>
<author>
<name>David Mosberger</name>
<email>davidm@egauge.net</email>
</author>
<published>2016-03-08T21:42:49+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=07d5d558e8711be09caa3783a8514514b3308e0f'/>
<id>07d5d558e8711be09caa3783a8514514b3308e0f</id>
<content type='text'>
commit 5f2e5fb873e269fcb806165715d237f0de4ecf1d upstream.

Restructure usb_sg_cancel() so we don't have to disable interrupts
while cancelling the URBs.

Suggested-by: Alan Stern &lt;stern@rowland.harvard.edu&gt;
Signed-off-by: David Mosberger &lt;davidm@egauge.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 5f2e5fb873e269fcb806165715d237f0de4ecf1d upstream.

Restructure usb_sg_cancel() so we don't have to disable interrupts
while cancelling the URBs.

Suggested-by: Alan Stern &lt;stern@rowland.harvard.edu&gt;
Signed-off-by: David Mosberger &lt;davidm@egauge.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drivers: usb: core: Don't disable irqs in usb_sg_wait() during URB submit.</title>
<updated>2020-06-11T18:05:39+00:00</updated>
<author>
<name>David Mosberger</name>
<email>davidm@egauge.net</email>
</author>
<published>2016-03-08T21:42:48+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=371262ec7bbf0ffc4b2a66c3f7c9230ee5e6a2c5'/>
<id>371262ec7bbf0ffc4b2a66c3f7c9230ee5e6a2c5</id>
<content type='text'>
commit 98b74b0ee57af1bcb6e8b2e76e707a71c5ef8ec9 upstream.

usb_submit_urb() may take quite long to execute.  For example, a
single sg list may have 30 or more entries, possibly leading to that
many calls to DMA-map pages.  This can cause interrupt latency of
several hundred micro-seconds.

Avoid the problem by releasing the io-&gt;lock spinlock and re-enabling
interrupts before calling usb_submit_urb().  This opens races with
usb_sg_cancel() and sg_complete().  Handle those races by using
usb_block_urb() to stop URBs from being submitted after
usb_sg_cancel() or sg_complete() with error.

Note that usb_unlink_urb() is guaranteed to return -ENODEV if
!io-&gt;urbs[i]-&gt;dev and since the -ENODEV case is already handled,
we don't have to check for !io-&gt;urbs[i]-&gt;dev explicitly.

Before this change, reading 512MB from an ext3 filesystem on a USB
memory stick showed a throughput of 12 MB/s with about 500 missed
deadlines.

With this change, reading the same file gave the same throughput but
only one or two missed deadlines.

Signed-off-by: David Mosberger &lt;davidm@egauge.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 98b74b0ee57af1bcb6e8b2e76e707a71c5ef8ec9 upstream.

usb_submit_urb() may take quite long to execute.  For example, a
single sg list may have 30 or more entries, possibly leading to that
many calls to DMA-map pages.  This can cause interrupt latency of
several hundred micro-seconds.

Avoid the problem by releasing the io-&gt;lock spinlock and re-enabling
interrupts before calling usb_submit_urb().  This opens races with
usb_sg_cancel() and sg_complete().  Handle those races by using
usb_block_urb() to stop URBs from being submitted after
usb_sg_cancel() or sg_complete() with error.

Note that usb_unlink_urb() is guaranteed to return -ENODEV if
!io-&gt;urbs[i]-&gt;dev and since the -ENODEV case is already handled,
we don't have to check for !io-&gt;urbs[i]-&gt;dev explicitly.

Before this change, reading 512MB from an ext3 filesystem on a USB
memory stick showed a throughput of 12 MB/s with about 500 missed
deadlines.

With this change, reading the same file gave the same throughput but
only one or two missed deadlines.

Signed-off-by: David Mosberger &lt;davidm@egauge.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>usb: core: hub: Improved device recognition on remote wakeup</title>
<updated>2020-04-28T18:03:27+00:00</updated>
<author>
<name>Keiya Nobuta</name>
<email>nobuta.keiya@fujitsu.com</email>
</author>
<published>2020-01-09T05:14:48+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=b9e00a5405345be002ad79c3c43e1c89ab06d384'/>
<id>b9e00a5405345be002ad79c3c43e1c89ab06d384</id>
<content type='text'>
commit 9c06ac4c83df6d6fbdbf7488fbad822b4002ba19 upstream.

If hub_activate() is called before D+ has stabilized after remote
wakeup, the following situation might occur:

         __      ___________________
        /  \    /
D+   __/    \__/

Hub  _______________________________
          |  ^   ^           ^
          |  |   |           |
Host _____v__|___|___________|______
          |  |   |           |
          |  |   |           \-- Interrupt Transfer (*3)
          |  |    \-- ClearPortFeature (*2)
          |   \-- GetPortStatus (*1)
          \-- Host detects remote wakeup

- D+ goes high, Host starts running by remote wakeup
- D+ is not stable, goes low
- Host requests GetPortStatus at (*1) and gets the following hub status:
  - Current Connect Status bit is 0
  - Connect Status Change bit is 1
- D+ stabilizes, goes high
- Host requests ClearPortFeature and thus Connect Status Change bit is
  cleared at (*2)
- After waiting 100 ms, Host starts the Interrupt Transfer at (*3)
- Since the Connect Status Change bit is 0, Hub returns NAK.

In this case, port_event() is not called in hub_event() and Host cannot
recognize device. To solve this issue, flag change_bits even if only
Connect Status Change bit is 1 when got in the first GetPortStatus.

This issue occurs rarely because it only if D+ changes during a very
short time between GetPortStatus and ClearPortFeature. However, it is
fatal if it occurs in embedded system.

Signed-off-by: Keiya Nobuta &lt;nobuta.keiya@fujitsu.com&gt;
Acked-by: Alan Stern &lt;stern@rowland.harvard.edu&gt;
Link: https://lore.kernel.org/r/20200109051448.28150-1-nobuta.keiya@fujitsu.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 9c06ac4c83df6d6fbdbf7488fbad822b4002ba19 upstream.

If hub_activate() is called before D+ has stabilized after remote
wakeup, the following situation might occur:

         __      ___________________
        /  \    /
D+   __/    \__/

Hub  _______________________________
          |  ^   ^           ^
          |  |   |           |
Host _____v__|___|___________|______
          |  |   |           |
          |  |   |           \-- Interrupt Transfer (*3)
          |  |    \-- ClearPortFeature (*2)
          |   \-- GetPortStatus (*1)
          \-- Host detects remote wakeup

- D+ goes high, Host starts running by remote wakeup
- D+ is not stable, goes low
- Host requests GetPortStatus at (*1) and gets the following hub status:
  - Current Connect Status bit is 0
  - Connect Status Change bit is 1
- D+ stabilizes, goes high
- Host requests ClearPortFeature and thus Connect Status Change bit is
  cleared at (*2)
- After waiting 100 ms, Host starts the Interrupt Transfer at (*3)
- Since the Connect Status Change bit is 0, Hub returns NAK.

In this case, port_event() is not called in hub_event() and Host cannot
recognize device. To solve this issue, flag change_bits even if only
Connect Status Change bit is 1 when got in the first GetPortStatus.

This issue occurs rarely because it only if D+ changes during a very
short time between GetPortStatus and ClearPortFeature. However, it is
fatal if it occurs in embedded system.

Signed-off-by: Keiya Nobuta &lt;nobuta.keiya@fujitsu.com&gt;
Acked-by: Alan Stern &lt;stern@rowland.harvard.edu&gt;
Link: https://lore.kernel.org/r/20200109051448.28150-1-nobuta.keiya@fujitsu.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>USB: quirks: blacklist duplicate ep on Sound Devices USBPre2</title>
<updated>2020-04-28T18:03:12+00:00</updated>
<author>
<name>Johan Hovold</name>
<email>johan@kernel.org</email>
</author>
<published>2020-02-03T15:38:29+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=488756587250fa6915d9adff84da203971727fe0'/>
<id>488756587250fa6915d9adff84da203971727fe0</id>
<content type='text'>
commit bdd1b147b8026df0e4260b387026b251d888ed01 upstream.

This device has a broken vendor-specific altsetting for interface 1,
where endpoint 0x85 is declared as an isochronous endpoint despite being
used by interface 2 for audio capture.

Device Descriptor:
  bLength                18
  bDescriptorType         1
  bcdUSB               2.00
  bDeviceClass          239 Miscellaneous Device
  bDeviceSubClass         2
  bDeviceProtocol         1 Interface Association
  bMaxPacketSize0        64
  idVendor           0x0926
  idProduct          0x0202
  bcdDevice            1.00
  iManufacturer           1 Sound Devices
  iProduct                2 USBPre2
  iSerial                 3 [...]
  bNumConfigurations      1

[...]

    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        1
      bAlternateSetting       3
      bNumEndpoints           2
      bInterfaceClass       255 Vendor Specific Class
      bInterfaceSubClass      0
      bInterfaceProtocol      0
      iInterface              0
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x85  EP 5 IN
        bmAttributes            5
          Transfer Type            Isochronous
          Synch Type               Asynchronous
          Usage Type               Data
        wMaxPacketSize     0x0126  1x 294 bytes
        bInterval               1

[...]

    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        2
      bAlternateSetting       1
      bNumEndpoints           1
      bInterfaceClass         1 Audio
      bInterfaceSubClass      2 Streaming
      bInterfaceProtocol      0
      iInterface              0
      AudioStreaming Interface Descriptor:
        bLength                 7
        bDescriptorType        36
        bDescriptorSubtype      1 (AS_GENERAL)
        bTerminalLink           4
        bDelay                  1 frames
        wFormatTag         0x0001 PCM
      AudioStreaming Interface Descriptor:
        bLength                26
        bDescriptorType        36
        bDescriptorSubtype      2 (FORMAT_TYPE)
        bFormatType             1 (FORMAT_TYPE_I)
        bNrChannels             2
        bSubframeSize           2
        bBitResolution         16
        bSamFreqType            6 Discrete
        tSamFreq[ 0]         8000
        tSamFreq[ 1]        16000
        tSamFreq[ 2]        24000
        tSamFreq[ 3]        32000
        tSamFreq[ 4]        44100
        tSamFreq[ 5]        48000
      Endpoint Descriptor:
        bLength                 9
        bDescriptorType         5
        bEndpointAddress     0x85  EP 5 IN
        bmAttributes            5
          Transfer Type            Isochronous
          Synch Type               Asynchronous
          Usage Type               Data
        wMaxPacketSize     0x0126  1x 294 bytes
        bInterval               4
        bRefresh                0
        bSynchAddress           0
        AudioStreaming Endpoint Descriptor:
          bLength                 7
          bDescriptorType        37
          bDescriptorSubtype      1 (EP_GENERAL)
          bmAttributes         0x01
            Sampling Frequency
          bLockDelayUnits         2 Decoded PCM samples
          wLockDelay         0x0000

Since commit 3e4f8e21c4f2 ("USB: core: fix check for duplicate
endpoints") USB core ignores any duplicate endpoints found during
descriptor parsing, but in this case we need to ignore the first
instance in order to avoid breaking the audio capture interface.

Fixes: 3e4f8e21c4f2 ("USB: core: fix check for duplicate endpoints")
Reported-by: edes &lt;edes@gmx.net&gt;
Tested-by: edes &lt;edes@gmx.net&gt;
Link: https://lore.kernel.org/r/20200201105829.5682c887@acme7.acmenet
Signed-off-by: Johan Hovold &lt;johan@kernel.org&gt;
Link: https://lore.kernel.org/r/20200203153830.26394-3-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit bdd1b147b8026df0e4260b387026b251d888ed01 upstream.

This device has a broken vendor-specific altsetting for interface 1,
where endpoint 0x85 is declared as an isochronous endpoint despite being
used by interface 2 for audio capture.

Device Descriptor:
  bLength                18
  bDescriptorType         1
  bcdUSB               2.00
  bDeviceClass          239 Miscellaneous Device
  bDeviceSubClass         2
  bDeviceProtocol         1 Interface Association
  bMaxPacketSize0        64
  idVendor           0x0926
  idProduct          0x0202
  bcdDevice            1.00
  iManufacturer           1 Sound Devices
  iProduct                2 USBPre2
  iSerial                 3 [...]
  bNumConfigurations      1

[...]

    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        1
      bAlternateSetting       3
      bNumEndpoints           2
      bInterfaceClass       255 Vendor Specific Class
      bInterfaceSubClass      0
      bInterfaceProtocol      0
      iInterface              0
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x85  EP 5 IN
        bmAttributes            5
          Transfer Type            Isochronous
          Synch Type               Asynchronous
          Usage Type               Data
        wMaxPacketSize     0x0126  1x 294 bytes
        bInterval               1

[...]

    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        2
      bAlternateSetting       1
      bNumEndpoints           1
      bInterfaceClass         1 Audio
      bInterfaceSubClass      2 Streaming
      bInterfaceProtocol      0
      iInterface              0
      AudioStreaming Interface Descriptor:
        bLength                 7
        bDescriptorType        36
        bDescriptorSubtype      1 (AS_GENERAL)
        bTerminalLink           4
        bDelay                  1 frames
        wFormatTag         0x0001 PCM
      AudioStreaming Interface Descriptor:
        bLength                26
        bDescriptorType        36
        bDescriptorSubtype      2 (FORMAT_TYPE)
        bFormatType             1 (FORMAT_TYPE_I)
        bNrChannels             2
        bSubframeSize           2
        bBitResolution         16
        bSamFreqType            6 Discrete
        tSamFreq[ 0]         8000
        tSamFreq[ 1]        16000
        tSamFreq[ 2]        24000
        tSamFreq[ 3]        32000
        tSamFreq[ 4]        44100
        tSamFreq[ 5]        48000
      Endpoint Descriptor:
        bLength                 9
        bDescriptorType         5
        bEndpointAddress     0x85  EP 5 IN
        bmAttributes            5
          Transfer Type            Isochronous
          Synch Type               Asynchronous
          Usage Type               Data
        wMaxPacketSize     0x0126  1x 294 bytes
        bInterval               4
        bRefresh                0
        bSynchAddress           0
        AudioStreaming Endpoint Descriptor:
          bLength                 7
          bDescriptorType        37
          bDescriptorSubtype      1 (EP_GENERAL)
          bmAttributes         0x01
            Sampling Frequency
          bLockDelayUnits         2 Decoded PCM samples
          wLockDelay         0x0000

Since commit 3e4f8e21c4f2 ("USB: core: fix check for duplicate
endpoints") USB core ignores any duplicate endpoints found during
descriptor parsing, but in this case we need to ignore the first
instance in order to avoid breaking the audio capture interface.

Fixes: 3e4f8e21c4f2 ("USB: core: fix check for duplicate endpoints")
Reported-by: edes &lt;edes@gmx.net&gt;
Tested-by: edes &lt;edes@gmx.net&gt;
Link: https://lore.kernel.org/r/20200201105829.5682c887@acme7.acmenet
Signed-off-by: Johan Hovold &lt;johan@kernel.org&gt;
Link: https://lore.kernel.org/r/20200203153830.26394-3-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>USB: core: add endpoint-blacklist quirk</title>
<updated>2020-04-28T18:03:11+00:00</updated>
<author>
<name>Johan Hovold</name>
<email>johan@kernel.org</email>
</author>
<published>2020-02-03T15:38:28+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=4a1d109a7a7f58960976e01e81de7a75bc0c8359'/>
<id>4a1d109a7a7f58960976e01e81de7a75bc0c8359</id>
<content type='text'>
commit 73f8bda9b5dc1c69df2bc55c0cbb24461a6391a9 upstream.

Add a new device quirk that can be used to blacklist endpoints.

Since commit 3e4f8e21c4f2 ("USB: core: fix check for duplicate
endpoints") USB core ignores any duplicate endpoints found during
descriptor parsing.

In order to handle devices where the first interfaces with duplicate
endpoints are the ones that should have their endpoints ignored, we need
to add a blacklist.

Tested-by: edes &lt;edes@gmx.net&gt;
Signed-off-by: Johan Hovold &lt;johan@kernel.org&gt;
Link: https://lore.kernel.org/r/20200203153830.26394-2-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 73f8bda9b5dc1c69df2bc55c0cbb24461a6391a9 upstream.

Add a new device quirk that can be used to blacklist endpoints.

Since commit 3e4f8e21c4f2 ("USB: core: fix check for duplicate
endpoints") USB core ignores any duplicate endpoints found during
descriptor parsing.

In order to handle devices where the first interfaces with duplicate
endpoints are the ones that should have their endpoints ignored, we need
to add a blacklist.

Tested-by: edes &lt;edes@gmx.net&gt;
Signed-off-by: Johan Hovold &lt;johan@kernel.org&gt;
Link: https://lore.kernel.org/r/20200203153830.26394-2-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>USB: core: fix check for duplicate endpoints</title>
<updated>2020-04-28T18:03:11+00:00</updated>
<author>
<name>Johan Hovold</name>
<email>johan@kernel.org</email>
</author>
<published>2019-12-19T16:10:16+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=acc7d80cde6232dd407987910538460cc65ceb26'/>
<id>acc7d80cde6232dd407987910538460cc65ceb26</id>
<content type='text'>
commit 3e4f8e21c4f27bcf30a48486b9dcc269512b79ff upstream.

Amend the endpoint-descriptor sanity checks to detect all duplicate
endpoint addresses in a configuration.

Commit 0a8fd1346254 ("USB: fix problems with duplicate endpoint
addresses") added a check for duplicate endpoint addresses within a
single alternate setting, but did not look for duplicate addresses in
other interfaces.

The current check would also not detect all duplicate addresses when one
endpoint is as a (bi-directional) control endpoint.

This specifically avoids overwriting the endpoint entries in struct
usb_device when enabling a duplicate endpoint, something which could
potentially lead to crashes or leaks, for example, when endpoints are
later disabled.

Signed-off-by: Johan Hovold &lt;johan@kernel.org&gt;
Acked-by: Alan Stern &lt;stern@rowland.harvard.edu&gt;
Link: https://lore.kernel.org/r/20191219161016.6695-1-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 3e4f8e21c4f27bcf30a48486b9dcc269512b79ff upstream.

Amend the endpoint-descriptor sanity checks to detect all duplicate
endpoint addresses in a configuration.

Commit 0a8fd1346254 ("USB: fix problems with duplicate endpoint
addresses") added a check for duplicate endpoint addresses within a
single alternate setting, but did not look for duplicate addresses in
other interfaces.

The current check would also not detect all duplicate addresses when one
endpoint is as a (bi-directional) control endpoint.

This specifically avoids overwriting the endpoint entries in struct
usb_device when enabling a duplicate endpoint, something which could
potentially lead to crashes or leaks, for example, when endpoints are
later disabled.

Signed-off-by: Johan Hovold &lt;johan@kernel.org&gt;
Acked-by: Alan Stern &lt;stern@rowland.harvard.edu&gt;
Link: https://lore.kernel.org/r/20191219161016.6695-1-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>usb: core: urb: fix URB structure initialization function</title>
<updated>2020-04-28T18:02:47+00:00</updated>
<author>
<name>Emiliano Ingrassia</name>
<email>ingrassia@epigenesys.com</email>
</author>
<published>2019-11-27T16:03:55+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=952c4f6a006968f00a9655aec3a4724cc0e61965'/>
<id>952c4f6a006968f00a9655aec3a4724cc0e61965</id>
<content type='text'>
commit 1cd17f7f0def31e3695501c4f86cd3faf8489840 upstream.

Explicitly initialize URB structure urb_list field in usb_init_urb().
This field can be potentially accessed uninitialized and its
initialization is coherent with the usage of list_del_init() in
usb_hcd_unlink_urb_from_ep() and usb_giveback_urb_bh() and its
explicit initialization in usb_hcd_submit_urb() error path.

Signed-off-by: Emiliano Ingrassia &lt;ingrassia@epigenesys.com&gt;
Link: https://lore.kernel.org/r/20191127160355.GA27196@ingrassia.epigenesys.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 1cd17f7f0def31e3695501c4f86cd3faf8489840 upstream.

Explicitly initialize URB structure urb_list field in usb_init_urb().
This field can be potentially accessed uninitialized and its
initialization is coherent with the usage of list_del_init() in
usb_hcd_unlink_urb_from_ep() and usb_giveback_urb_bh() and its
explicit initialization in usb_hcd_submit_urb() error path.

Signed-off-by: Emiliano Ingrassia &lt;ingrassia@epigenesys.com&gt;
Link: https://lore.kernel.org/r/20191127160355.GA27196@ingrassia.epigenesys.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>usb: Allow USB device to be warm reset in suspended state</title>
<updated>2020-02-11T20:03:32+00:00</updated>
<author>
<name>Kai-Heng Feng</name>
<email>kai.heng.feng@canonical.com</email>
</author>
<published>2019-11-06T06:27:10+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=d1a595ab1cefd3ee9211b08b49c367b039a4e5df'/>
<id>d1a595ab1cefd3ee9211b08b49c367b039a4e5df</id>
<content type='text'>
commit e76b3bf7654c3c94554c24ba15a3d105f4006c80 upstream.

On Dell WD15 dock, sometimes USB ethernet cannot be detected after plugging
cable to the ethernet port, the hub and roothub get runtime resumed and
runtime suspended immediately:
...
[  433.315169] xhci_hcd 0000:3a:00.0: hcd_pci_runtime_resume: 0
[  433.315204] usb usb4: usb auto-resume
[  433.315226] hub 4-0:1.0: hub_resume
[  433.315239] xhci_hcd 0000:3a:00.0: Get port status 4-1 read: 0x10202e2, return 0x10343
[  433.315264] usb usb4-port1: status 0343 change 0001
[  433.315279] xhci_hcd 0000:3a:00.0: clear port1 connect change, portsc: 0x10002e2
[  433.315293] xhci_hcd 0000:3a:00.0: Get port status 4-2 read: 0x2a0, return 0x2a0
[  433.317012] xhci_hcd 0000:3a:00.0: xhci_hub_status_data: stopping port polling.
[  433.422282] xhci_hcd 0000:3a:00.0: Get port status 4-1 read: 0x10002e2, return 0x343
[  433.422307] usb usb4-port1: do warm reset
[  433.422311] usb 4-1: device reset not allowed in state 8
[  433.422339] hub 4-0:1.0: state 7 ports 2 chg 0002 evt 0000
[  433.422346] xhci_hcd 0000:3a:00.0: Get port status 4-1 read: 0x10002e2, return 0x343
[  433.422356] usb usb4-port1: do warm reset
[  433.422358] usb 4-1: device reset not allowed in state 8
[  433.422428] xhci_hcd 0000:3a:00.0: set port remote wake mask, actual port 0 status  = 0xf0002e2
[  433.422455] xhci_hcd 0000:3a:00.0: set port remote wake mask, actual port 1 status  = 0xe0002a0
[  433.422465] hub 4-0:1.0: hub_suspend
[  433.422475] usb usb4: bus auto-suspend, wakeup 1
[  433.426161] xhci_hcd 0000:3a:00.0: xhci_hub_status_data: stopping port polling.
[  433.466209] xhci_hcd 0000:3a:00.0: port 0 polling in bus suspend, waiting
[  433.510204] xhci_hcd 0000:3a:00.0: port 0 polling in bus suspend, waiting
[  433.554051] xhci_hcd 0000:3a:00.0: port 0 polling in bus suspend, waiting
[  433.598235] xhci_hcd 0000:3a:00.0: port 0 polling in bus suspend, waiting
[  433.642154] xhci_hcd 0000:3a:00.0: port 0 polling in bus suspend, waiting
[  433.686204] xhci_hcd 0000:3a:00.0: port 0 polling in bus suspend, waiting
[  433.730205] xhci_hcd 0000:3a:00.0: port 0 polling in bus suspend, waiting
[  433.774203] xhci_hcd 0000:3a:00.0: port 0 polling in bus suspend, waiting
[  433.818207] xhci_hcd 0000:3a:00.0: port 0 polling in bus suspend, waiting
[  433.862040] xhci_hcd 0000:3a:00.0: port 0 polling in bus suspend, waiting
[  433.862053] xhci_hcd 0000:3a:00.0: xhci_hub_status_data: stopping port polling.
[  433.862077] xhci_hcd 0000:3a:00.0: xhci_suspend: stopping port polling.
[  433.862096] xhci_hcd 0000:3a:00.0: // Setting command ring address to 0x8578fc001
[  433.862312] xhci_hcd 0000:3a:00.0: hcd_pci_runtime_suspend: 0
[  433.862445] xhci_hcd 0000:3a:00.0: PME# enabled
[  433.902376] xhci_hcd 0000:3a:00.0: restoring config space at offset 0xc (was 0x0, writing 0x20)
[  433.902395] xhci_hcd 0000:3a:00.0: restoring config space at offset 0x4 (was 0x100000, writing 0x100403)
[  433.902490] xhci_hcd 0000:3a:00.0: PME# disabled
[  433.902504] xhci_hcd 0000:3a:00.0: enabling bus mastering
[  433.902547] xhci_hcd 0000:3a:00.0: // Setting command ring address to 0x8578fc001
[  433.902649] pcieport 0000:00:1b.0: PME: Spurious native interrupt!
[  433.902839] xhci_hcd 0000:3a:00.0: Port change event, 4-1, id 3, portsc: 0xb0202e2
[  433.902842] xhci_hcd 0000:3a:00.0: resume root hub
[  433.902845] xhci_hcd 0000:3a:00.0: handle_port_status: starting port polling.
[  433.902877] xhci_hcd 0000:3a:00.0: xhci_resume: starting port polling.
[  433.902889] xhci_hcd 0000:3a:00.0: xhci_hub_status_data: stopping port polling.
[  433.902891] xhci_hcd 0000:3a:00.0: hcd_pci_runtime_resume: 0
[  433.902919] usb usb4: usb wakeup-resume
[  433.902942] usb usb4: usb auto-resume
[  433.902966] hub 4-0:1.0: hub_resume
...

As Mathias pointed out, the hub enters Cold Attach Status state and
requires a warm reset. However usb_reset_device() bails out early when
the device is in suspended state, as its callers port_event() and
hub_event() don't always resume the device.

Since there's nothing wrong to reset a suspended device, allow
usb_reset_device() to do so to solve the issue.

Signed-off-by: Kai-Heng Feng &lt;kai.heng.feng@canonical.com&gt;
Acked-by: Alan Stern &lt;stern@rowland.harvard.edu&gt;
Link: https://lore.kernel.org/r/20191106062710.29880-1-kai.heng.feng@canonical.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit e76b3bf7654c3c94554c24ba15a3d105f4006c80 upstream.

On Dell WD15 dock, sometimes USB ethernet cannot be detected after plugging
cable to the ethernet port, the hub and roothub get runtime resumed and
runtime suspended immediately:
...
[  433.315169] xhci_hcd 0000:3a:00.0: hcd_pci_runtime_resume: 0
[  433.315204] usb usb4: usb auto-resume
[  433.315226] hub 4-0:1.0: hub_resume
[  433.315239] xhci_hcd 0000:3a:00.0: Get port status 4-1 read: 0x10202e2, return 0x10343
[  433.315264] usb usb4-port1: status 0343 change 0001
[  433.315279] xhci_hcd 0000:3a:00.0: clear port1 connect change, portsc: 0x10002e2
[  433.315293] xhci_hcd 0000:3a:00.0: Get port status 4-2 read: 0x2a0, return 0x2a0
[  433.317012] xhci_hcd 0000:3a:00.0: xhci_hub_status_data: stopping port polling.
[  433.422282] xhci_hcd 0000:3a:00.0: Get port status 4-1 read: 0x10002e2, return 0x343
[  433.422307] usb usb4-port1: do warm reset
[  433.422311] usb 4-1: device reset not allowed in state 8
[  433.422339] hub 4-0:1.0: state 7 ports 2 chg 0002 evt 0000
[  433.422346] xhci_hcd 0000:3a:00.0: Get port status 4-1 read: 0x10002e2, return 0x343
[  433.422356] usb usb4-port1: do warm reset
[  433.422358] usb 4-1: device reset not allowed in state 8
[  433.422428] xhci_hcd 0000:3a:00.0: set port remote wake mask, actual port 0 status  = 0xf0002e2
[  433.422455] xhci_hcd 0000:3a:00.0: set port remote wake mask, actual port 1 status  = 0xe0002a0
[  433.422465] hub 4-0:1.0: hub_suspend
[  433.422475] usb usb4: bus auto-suspend, wakeup 1
[  433.426161] xhci_hcd 0000:3a:00.0: xhci_hub_status_data: stopping port polling.
[  433.466209] xhci_hcd 0000:3a:00.0: port 0 polling in bus suspend, waiting
[  433.510204] xhci_hcd 0000:3a:00.0: port 0 polling in bus suspend, waiting
[  433.554051] xhci_hcd 0000:3a:00.0: port 0 polling in bus suspend, waiting
[  433.598235] xhci_hcd 0000:3a:00.0: port 0 polling in bus suspend, waiting
[  433.642154] xhci_hcd 0000:3a:00.0: port 0 polling in bus suspend, waiting
[  433.686204] xhci_hcd 0000:3a:00.0: port 0 polling in bus suspend, waiting
[  433.730205] xhci_hcd 0000:3a:00.0: port 0 polling in bus suspend, waiting
[  433.774203] xhci_hcd 0000:3a:00.0: port 0 polling in bus suspend, waiting
[  433.818207] xhci_hcd 0000:3a:00.0: port 0 polling in bus suspend, waiting
[  433.862040] xhci_hcd 0000:3a:00.0: port 0 polling in bus suspend, waiting
[  433.862053] xhci_hcd 0000:3a:00.0: xhci_hub_status_data: stopping port polling.
[  433.862077] xhci_hcd 0000:3a:00.0: xhci_suspend: stopping port polling.
[  433.862096] xhci_hcd 0000:3a:00.0: // Setting command ring address to 0x8578fc001
[  433.862312] xhci_hcd 0000:3a:00.0: hcd_pci_runtime_suspend: 0
[  433.862445] xhci_hcd 0000:3a:00.0: PME# enabled
[  433.902376] xhci_hcd 0000:3a:00.0: restoring config space at offset 0xc (was 0x0, writing 0x20)
[  433.902395] xhci_hcd 0000:3a:00.0: restoring config space at offset 0x4 (was 0x100000, writing 0x100403)
[  433.902490] xhci_hcd 0000:3a:00.0: PME# disabled
[  433.902504] xhci_hcd 0000:3a:00.0: enabling bus mastering
[  433.902547] xhci_hcd 0000:3a:00.0: // Setting command ring address to 0x8578fc001
[  433.902649] pcieport 0000:00:1b.0: PME: Spurious native interrupt!
[  433.902839] xhci_hcd 0000:3a:00.0: Port change event, 4-1, id 3, portsc: 0xb0202e2
[  433.902842] xhci_hcd 0000:3a:00.0: resume root hub
[  433.902845] xhci_hcd 0000:3a:00.0: handle_port_status: starting port polling.
[  433.902877] xhci_hcd 0000:3a:00.0: xhci_resume: starting port polling.
[  433.902889] xhci_hcd 0000:3a:00.0: xhci_hub_status_data: stopping port polling.
[  433.902891] xhci_hcd 0000:3a:00.0: hcd_pci_runtime_resume: 0
[  433.902919] usb usb4: usb wakeup-resume
[  433.902942] usb usb4: usb auto-resume
[  433.902966] hub 4-0:1.0: hub_resume
...

As Mathias pointed out, the hub enters Cold Attach Status state and
requires a warm reset. However usb_reset_device() bails out early when
the device is in suspended state, as its callers port_event() and
hub_event() don't always resume the device.

Since there's nothing wrong to reset a suspended device, allow
usb_reset_device() to do so to solve the issue.

Signed-off-by: Kai-Heng Feng &lt;kai.heng.feng@canonical.com&gt;
Acked-by: Alan Stern &lt;stern@rowland.harvard.edu&gt;
Link: https://lore.kernel.org/r/20191106062710.29880-1-kai.heng.feng@canonical.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>USB: usbcore: Fix slab-out-of-bounds bug during device reset</title>
<updated>2019-12-10T18:01:16+00:00</updated>
<author>
<name>Alan Stern</name>
<email>stern@rowland.harvard.edu</email>
</author>
<published>2019-09-04T15:56:27+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=77ce180d68beffd1af620d0121590e16683fc6b8'/>
<id>77ce180d68beffd1af620d0121590e16683fc6b8</id>
<content type='text'>
commit 3dd550a2d36596a1b0ee7955da3b611c031d3873 upstream.

The syzbot fuzzer provoked a slab-out-of-bounds error in the USB core:

BUG: KASAN: slab-out-of-bounds in memcmp+0xa6/0xb0 lib/string.c:904
Read of size 1 at addr ffff8881d175bed6 by task kworker/0:3/2746

CPU: 0 PID: 2746 Comm: kworker/0:3 Not tainted 5.3.0-rc5+ #28
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+0xca/0x13e lib/dump_stack.c:113
  print_address_description+0x6a/0x32c mm/kasan/report.c:351
  __kasan_report.cold+0x1a/0x33 mm/kasan/report.c:482
  kasan_report+0xe/0x12 mm/kasan/common.c:612
  memcmp+0xa6/0xb0 lib/string.c:904
  memcmp include/linux/string.h:400 [inline]
  descriptors_changed drivers/usb/core/hub.c:5579 [inline]
  usb_reset_and_verify_device+0x564/0x1300 drivers/usb/core/hub.c:5729
  usb_reset_device+0x4c1/0x920 drivers/usb/core/hub.c:5898
  rt2x00usb_probe+0x53/0x7af
drivers/net/wireless/ralink/rt2x00/rt2x00usb.c:806

The error occurs when the descriptors_changed() routine (called during
a device reset) attempts to compare the old and new BOS and capability
descriptors.  The length it uses for the comparison is the
wTotalLength value stored in BOS descriptor, but this value is not
necessarily the same as the length actually allocated for the
descriptors.  If it is larger the routine will call memcmp() with a
length that is too big, thus reading beyond the end of the allocated
region and leading to this fault.

The kernel reads the BOS descriptor twice: first to get the total
length of all the capability descriptors, and second to read it along
with all those other descriptors.  A malicious (or very faulty) device
may send different values for the BOS descriptor fields each time.
The memory area will be allocated using the wTotalLength value read
the first time, but stored within it will be the value read the second
time.

To prevent this possibility from causing any errors, this patch
modifies the BOS descriptor after it has been read the second time:
It sets the wTotalLength field to the actual length of the descriptors
that were read in and validated.  Then the memcpy() call, or any other
code using these descriptors, will be able to rely on wTotalLength
being valid.

Reported-and-tested-by: syzbot+35f4d916c623118d576e@syzkaller.appspotmail.com
Signed-off-by: Alan Stern &lt;stern@rowland.harvard.edu&gt;
Link: https://lore.kernel.org/r/Pine.LNX.4.44L0.1909041154260.1722-100000@iolanthe.rowland.org
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 3dd550a2d36596a1b0ee7955da3b611c031d3873 upstream.

The syzbot fuzzer provoked a slab-out-of-bounds error in the USB core:

BUG: KASAN: slab-out-of-bounds in memcmp+0xa6/0xb0 lib/string.c:904
Read of size 1 at addr ffff8881d175bed6 by task kworker/0:3/2746

CPU: 0 PID: 2746 Comm: kworker/0:3 Not tainted 5.3.0-rc5+ #28
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+0xca/0x13e lib/dump_stack.c:113
  print_address_description+0x6a/0x32c mm/kasan/report.c:351
  __kasan_report.cold+0x1a/0x33 mm/kasan/report.c:482
  kasan_report+0xe/0x12 mm/kasan/common.c:612
  memcmp+0xa6/0xb0 lib/string.c:904
  memcmp include/linux/string.h:400 [inline]
  descriptors_changed drivers/usb/core/hub.c:5579 [inline]
  usb_reset_and_verify_device+0x564/0x1300 drivers/usb/core/hub.c:5729
  usb_reset_device+0x4c1/0x920 drivers/usb/core/hub.c:5898
  rt2x00usb_probe+0x53/0x7af
drivers/net/wireless/ralink/rt2x00/rt2x00usb.c:806

The error occurs when the descriptors_changed() routine (called during
a device reset) attempts to compare the old and new BOS and capability
descriptors.  The length it uses for the comparison is the
wTotalLength value stored in BOS descriptor, but this value is not
necessarily the same as the length actually allocated for the
descriptors.  If it is larger the routine will call memcmp() with a
length that is too big, thus reading beyond the end of the allocated
region and leading to this fault.

The kernel reads the BOS descriptor twice: first to get the total
length of all the capability descriptors, and second to read it along
with all those other descriptors.  A malicious (or very faulty) device
may send different values for the BOS descriptor fields each time.
The memory area will be allocated using the wTotalLength value read
the first time, but stored within it will be the value read the second
time.

To prevent this possibility from causing any errors, this patch
modifies the BOS descriptor after it has been read the second time:
It sets the wTotalLength field to the actual length of the descriptors
that were read in and validated.  Then the memcpy() call, or any other
code using these descriptors, will be able to rely on wTotalLength
being valid.

Reported-and-tested-by: syzbot+35f4d916c623118d576e@syzkaller.appspotmail.com
Signed-off-by: Alan Stern &lt;stern@rowland.harvard.edu&gt;
Link: https://lore.kernel.org/r/Pine.LNX.4.44L0.1909041154260.1722-100000@iolanthe.rowland.org
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</pre>
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