<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/drivers/usb/core/message.c, branch v5.10</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>Merge tag 'dma-mapping-5.10' of git://git.infradead.org/users/hch/dma-mapping</title>
<updated>2020-10-15T21:43:29+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2020-10-15T21:43:29+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=5a32c3413d3340f90c82c84b375ad4b335a59f28'/>
<id>5a32c3413d3340f90c82c84b375ad4b335a59f28</id>
<content type='text'>
Pull dma-mapping updates from Christoph Hellwig:

 - rework the non-coherent DMA allocator

 - move private definitions out of &lt;linux/dma-mapping.h&gt;

 - lower CMA_ALIGNMENT (Paul Cercueil)

 - remove the omap1 dma address translation in favor of the common code

 - make dma-direct aware of multiple dma offset ranges (Jim Quinlan)

 - support per-node DMA CMA areas (Barry Song)

 - increase the default seg boundary limit (Nicolin Chen)

 - misc fixes (Robin Murphy, Thomas Tai, Xu Wang)

 - various cleanups

* tag 'dma-mapping-5.10' of git://git.infradead.org/users/hch/dma-mapping: (63 commits)
  ARM/ixp4xx: add a missing include of dma-map-ops.h
  dma-direct: simplify the DMA_ATTR_NO_KERNEL_MAPPING handling
  dma-direct: factor out a dma_direct_alloc_from_pool helper
  dma-direct check for highmem pages in dma_direct_alloc_pages
  dma-mapping: merge &lt;linux/dma-noncoherent.h&gt; into &lt;linux/dma-map-ops.h&gt;
  dma-mapping: move large parts of &lt;linux/dma-direct.h&gt; to kernel/dma
  dma-mapping: move dma-debug.h to kernel/dma/
  dma-mapping: remove &lt;asm/dma-contiguous.h&gt;
  dma-mapping: merge &lt;linux/dma-contiguous.h&gt; into &lt;linux/dma-map-ops.h&gt;
  dma-contiguous: remove dma_contiguous_set_default
  dma-contiguous: remove dev_set_cma_area
  dma-contiguous: remove dma_declare_contiguous
  dma-mapping: split &lt;linux/dma-mapping.h&gt;
  cma: decrease CMA_ALIGNMENT lower limit to 2
  firewire-ohci: use dma_alloc_pages
  dma-iommu: implement -&gt;alloc_noncoherent
  dma-mapping: add new {alloc,free}_noncoherent dma_map_ops methods
  dma-mapping: add a new dma_alloc_pages API
  dma-mapping: remove dma_cache_sync
  53c700: convert to dma_alloc_noncoherent
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull dma-mapping updates from Christoph Hellwig:

 - rework the non-coherent DMA allocator

 - move private definitions out of &lt;linux/dma-mapping.h&gt;

 - lower CMA_ALIGNMENT (Paul Cercueil)

 - remove the omap1 dma address translation in favor of the common code

 - make dma-direct aware of multiple dma offset ranges (Jim Quinlan)

 - support per-node DMA CMA areas (Barry Song)

 - increase the default seg boundary limit (Nicolin Chen)

 - misc fixes (Robin Murphy, Thomas Tai, Xu Wang)

 - various cleanups

* tag 'dma-mapping-5.10' of git://git.infradead.org/users/hch/dma-mapping: (63 commits)
  ARM/ixp4xx: add a missing include of dma-map-ops.h
  dma-direct: simplify the DMA_ATTR_NO_KERNEL_MAPPING handling
  dma-direct: factor out a dma_direct_alloc_from_pool helper
  dma-direct check for highmem pages in dma_direct_alloc_pages
  dma-mapping: merge &lt;linux/dma-noncoherent.h&gt; into &lt;linux/dma-map-ops.h&gt;
  dma-mapping: move large parts of &lt;linux/dma-direct.h&gt; to kernel/dma
  dma-mapping: move dma-debug.h to kernel/dma/
  dma-mapping: remove &lt;asm/dma-contiguous.h&gt;
  dma-mapping: merge &lt;linux/dma-contiguous.h&gt; into &lt;linux/dma-map-ops.h&gt;
  dma-contiguous: remove dma_contiguous_set_default
  dma-contiguous: remove dev_set_cma_area
  dma-contiguous: remove dma_declare_contiguous
  dma-mapping: split &lt;linux/dma-mapping.h&gt;
  cma: decrease CMA_ALIGNMENT lower limit to 2
  firewire-ohci: use dma_alloc_pages
  dma-iommu: implement -&gt;alloc_noncoherent
  dma-mapping: add new {alloc,free}_noncoherent dma_map_ops methods
  dma-mapping: add a new dma_alloc_pages API
  dma-mapping: remove dma_cache_sync
  53c700: convert to dma_alloc_noncoherent
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>USB: correct API of usb_control_msg_send/recv</title>
<updated>2020-09-25T14:33:58+00:00</updated>
<author>
<name>Oliver Neukum</name>
<email>oneukum@suse.com</email>
</author>
<published>2020-09-23T13:43:42+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=ddd1198e3e0935066d6e309180d49f64ef4fa702'/>
<id>ddd1198e3e0935066d6e309180d49f64ef4fa702</id>
<content type='text'>
They need to specify how memory is to be allocated,
as control messages need to work in contexts that require GFP_NOIO.

Signed-off-by: Oliver Neukum &lt;oneukum@suse.com&gt;
Link: https://lore.kernel.org/r/20200923134348.23862-9-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>
They need to specify how memory is to be allocated,
as control messages need to work in contexts that require GFP_NOIO.

Signed-off-by: Oliver Neukum &lt;oneukum@suse.com&gt;
Link: https://lore.kernel.org/r/20200923134348.23862-9-oneukum@suse.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branch 'master' of https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux into dma-mapping-for-next</title>
<updated>2020-09-25T04:19:19+00:00</updated>
<author>
<name>Christoph Hellwig</name>
<email>hch@lst.de</email>
</author>
<published>2020-09-25T04:19:19+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=8c1c6c7588b2faf9dd45fb3cfb7497fd09bbfe7c'/>
<id>8c1c6c7588b2faf9dd45fb3cfb7497fd09bbfe7c</id>
<content type='text'>
Pull in the latest 5.9 tree for the commit to revert the
V4L2_FLAG_MEMORY_NON_CONSISTENT uapi addition.
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull in the latest 5.9 tree for the commit to revert the
V4L2_FLAG_MEMORY_NON_CONSISTENT uapi addition.
</pre>
</div>
</content>
</entry>
<entry>
<title>usb: don't inherity DMA properties for USB devices</title>
<updated>2020-09-17T16:43:25+00:00</updated>
<author>
<name>Christoph Hellwig</name>
<email>hch@lst.de</email>
</author>
<published>2020-09-10T16:03:49+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=6eb0233ec2d0df288fe8515d5b0b2b15562e05bb'/>
<id>6eb0233ec2d0df288fe8515d5b0b2b15562e05bb</id>
<content type='text'>
As the comment in usb_alloc_dev correctly states, drivers can't use
the DMA API on usb device, and at least calling dma_set_mask on them
is highly dangerous.  Unlike what the comment states upper level drivers
also can't really use the presence of a dma mask to check for DMA
support, as the dma_mask is set by default for most busses.

Setting the dma_mask comes from "[PATCH] usbcore dma updates (and doc)"
in BitKeeper times, as it seems like it was primarily for setting the
NETIF_F_HIGHDMA flag in USB drivers, something that has long been
fixed up since.

Setting the dma_pfn_offset comes from commit b44bbc46a8bb
("usb: core: setup dma_pfn_offset for USB devices and, interfaces"),
which worked around the fact that the scsi_calculate_bounce_limits
functions wasn't going through the proper driver interface to query
DMA information, but that function was removed in commit 21e07dba9fb1
("scsi: reduce use of block bounce buffers") years ago.

Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
Reviewed-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
As the comment in usb_alloc_dev correctly states, drivers can't use
the DMA API on usb device, and at least calling dma_set_mask on them
is highly dangerous.  Unlike what the comment states upper level drivers
also can't really use the presence of a dma mask to check for DMA
support, as the dma_mask is set by default for most busses.

Setting the dma_mask comes from "[PATCH] usbcore dma updates (and doc)"
in BitKeeper times, as it seems like it was primarily for setting the
NETIF_F_HIGHDMA flag in USB drivers, something that has long been
fixed up since.

Setting the dma_pfn_offset comes from commit b44bbc46a8bb
("usb: core: setup dma_pfn_offset for USB devices and, interfaces"),
which worked around the fact that the scsi_calculate_bounce_limits
functions wasn't going through the proper driver interface to query
DMA information, but that function was removed in commit 21e07dba9fb1
("scsi: reduce use of block bounce buffers") years ago.

Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
Reviewed-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>USB: core: message.c: use usb_control_msg_send() in a few places</title>
<updated>2020-09-16T09:02:35+00:00</updated>
<author>
<name>Greg Kroah-Hartman</name>
<email>gregkh@linuxfoundation.org</email>
</author>
<published>2020-09-14T15:37:48+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=297e84c04d76b9fdbac463e6378f5db7e9283ecd'/>
<id>297e84c04d76b9fdbac463e6378f5db7e9283ecd</id>
<content type='text'>
There are a few calls to usb_control_msg() that can be converted to use
usb_control_msg_send() instead, so do that in order to make the error
checking a bit simpler.

Cc: Alan Stern &lt;stern@rowland.harvard.edu&gt;
Cc: "Rafael J. Wysocki" &lt;rafael.j.wysocki@intel.com&gt;
Reviewed-by: Andy Shevchenko &lt;andriy.shevchenko@linux.intel.com&gt;
Link: https://lore.kernel.org/r/20200914153756.3412156-4-gregkh@linuxfoundation.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>
There are a few calls to usb_control_msg() that can be converted to use
usb_control_msg_send() instead, so do that in order to make the error
checking a bit simpler.

Cc: Alan Stern &lt;stern@rowland.harvard.edu&gt;
Cc: "Rafael J. Wysocki" &lt;rafael.j.wysocki@intel.com&gt;
Reviewed-by: Andy Shevchenko &lt;andriy.shevchenko@linux.intel.com&gt;
Link: https://lore.kernel.org/r/20200914153756.3412156-4-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>USB: add usb_control_msg_send() and usb_control_msg_recv()</title>
<updated>2020-09-16T09:02:32+00:00</updated>
<author>
<name>Greg Kroah-Hartman</name>
<email>gregkh@linuxfoundation.org</email>
</author>
<published>2020-09-14T15:37:47+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=719b8f2850d3d9b863cc5e4f08e9ef0206e45b26'/>
<id>719b8f2850d3d9b863cc5e4f08e9ef0206e45b26</id>
<content type='text'>
New core functions to make sending/receiving USB control messages easier
and saner.

In discussions, it turns out that the large majority of users of
usb_control_msg() do so in potentially incorrect ways.  The most common
issue is where a "short" message is received, yet never detected
properly due to "incorrect" error handling.

Handle all of this in the USB core with two new functions to try to make
working with USB control messages simpler.

No more need for dynamic data, messages can be on the stack, and only
"complete" send/receive will work without causing an error.

Link: https://lore.kernel.org/r/20200914153756.3412156-3-gregkh@linuxfoundation.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>
New core functions to make sending/receiving USB control messages easier
and saner.

In discussions, it turns out that the large majority of users of
usb_control_msg() do so in potentially incorrect ways.  The most common
issue is where a "short" message is received, yet never detected
properly due to "incorrect" error handling.

Handle all of this in the USB core with two new functions to try to make
working with USB control messages simpler.

No more need for dynamic data, messages can be on the stack, and only
"complete" send/receive will work without causing an error.

Link: https://lore.kernel.org/r/20200914153756.3412156-3-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>usb: Fix out of sync data toggle if a configured device is reconfigured</title>
<updated>2020-09-04T14:41:22+00:00</updated>
<author>
<name>Mathias Nyman</name>
<email>mathias.nyman@linux.intel.com</email>
</author>
<published>2020-09-01T08:25:28+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=cfd54fa83a5068b61b7eb28d3c117d8354c74c7a'/>
<id>cfd54fa83a5068b61b7eb28d3c117d8354c74c7a</id>
<content type='text'>
Userspace drivers that use a SetConfiguration() request to "lightweight"
reset an already configured usb device might cause data toggles to get out
of sync between the device and host, and the device becomes unusable.

The xHCI host requires endpoints to be dropped and added back to reset the
toggle. If USB core notices the new configuration is the same as the
current active configuration it will avoid these extra steps by calling
usb_reset_configuration() instead of usb_set_configuration().

A SetConfiguration() request will reset the device side data toggles.
Make sure usb_reset_configuration() function also drops and adds back the
endpoints to ensure data toggles are in sync.

To avoid code duplication split the current usb_disable_device() function
and reuse the endpoint specific part.

Cc: stable &lt;stable@vger.kernel.org&gt;
Tested-by: Martin Thierer &lt;mthierer@gmail.com&gt;
Signed-off-by: Mathias Nyman &lt;mathias.nyman@linux.intel.com&gt;
Link: https://lore.kernel.org/r/20200901082528.12557-1-mathias.nyman@linux.intel.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>
Userspace drivers that use a SetConfiguration() request to "lightweight"
reset an already configured usb device might cause data toggles to get out
of sync between the device and host, and the device becomes unusable.

The xHCI host requires endpoints to be dropped and added back to reset the
toggle. If USB core notices the new configuration is the same as the
current active configuration it will avoid these extra steps by calling
usb_reset_configuration() instead of usb_set_configuration().

A SetConfiguration() request will reset the device side data toggles.
Make sure usb_reset_configuration() function also drops and adds back the
endpoints to ensure data toggles are in sync.

To avoid code duplication split the current usb_disable_device() function
and reuse the endpoint specific part.

Cc: stable &lt;stable@vger.kernel.org&gt;
Tested-by: Martin Thierer &lt;mthierer@gmail.com&gt;
Signed-off-by: Mathias Nyman &lt;mathias.nyman@linux.intel.com&gt;
Link: https://lore.kernel.org/r/20200901082528.12557-1-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>USB: core: Fix misleading driver bug report</title>
<updated>2020-05-05T11:06:45+00:00</updated>
<author>
<name>Alan Stern</name>
<email>stern@rowland.harvard.edu</email>
</author>
<published>2020-05-01T20:07:28+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=ac854131d9844f79e2fdcef67a7707227538d78a'/>
<id>ac854131d9844f79e2fdcef67a7707227538d78a</id>
<content type='text'>
The syzbot fuzzer found a race between URB submission to endpoint 0
and device reset.  Namely, during the reset we call usb_ep0_reinit()
because the characteristics of ep0 may have changed (if the reset
follows a firmware update, for example).  While usb_ep0_reinit() is
running there is a brief period during which the pointers stored in
udev-&gt;ep_in[0] and udev-&gt;ep_out[0] are set to NULL, and if an URB is
submitted to ep0 during that period, usb_urb_ep_type_check() will
report it as a driver bug.  In the absence of those pointers, the
routine thinks that the endpoint doesn't exist.  The log message looks
like this:

------------[ cut here ]------------
usb 2-1: BOGUS urb xfer, pipe 2 != type 2
WARNING: CPU: 0 PID: 9241 at drivers/usb/core/urb.c:478
usb_submit_urb+0x1188/0x1460 drivers/usb/core/urb.c:478

Now, although submitting an URB while the device is being reset is a
questionable thing to do, it shouldn't count as a driver bug as severe
as submitting an URB for an endpoint that doesn't exist.  Indeed,
endpoint 0 always exists, even while the device is in its unconfigured
state.

To prevent these misleading driver bug reports, this patch updates
usb_disable_endpoint() to avoid clearing the ep_in[] and ep_out[]
pointers when the endpoint being disabled is ep0.  There's no danger
of leaving a stale pointer in place, because the usb_host_endpoint
structure being pointed to is stored permanently in udev-&gt;ep0; it
doesn't get deallocated until the entire usb_device structure does.

Reported-and-tested-by: syzbot+db339689b2101f6f6071@syzkaller.appspotmail.com
Signed-off-by: Alan Stern &lt;stern@rowland.harvard.edu&gt;

Link: https://lore.kernel.org/r/Pine.LNX.4.44L0.2005011558590.903-100000@netrider.rowland.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>
The syzbot fuzzer found a race between URB submission to endpoint 0
and device reset.  Namely, during the reset we call usb_ep0_reinit()
because the characteristics of ep0 may have changed (if the reset
follows a firmware update, for example).  While usb_ep0_reinit() is
running there is a brief period during which the pointers stored in
udev-&gt;ep_in[0] and udev-&gt;ep_out[0] are set to NULL, and if an URB is
submitted to ep0 during that period, usb_urb_ep_type_check() will
report it as a driver bug.  In the absence of those pointers, the
routine thinks that the endpoint doesn't exist.  The log message looks
like this:

------------[ cut here ]------------
usb 2-1: BOGUS urb xfer, pipe 2 != type 2
WARNING: CPU: 0 PID: 9241 at drivers/usb/core/urb.c:478
usb_submit_urb+0x1188/0x1460 drivers/usb/core/urb.c:478

Now, although submitting an URB while the device is being reset is a
questionable thing to do, it shouldn't count as a driver bug as severe
as submitting an URB for an endpoint that doesn't exist.  Indeed,
endpoint 0 always exists, even while the device is in its unconfigured
state.

To prevent these misleading driver bug reports, this patch updates
usb_disable_endpoint() to avoid clearing the ep_in[] and ep_out[]
pointers when the endpoint being disabled is ep0.  There's no danger
of leaving a stale pointer in place, because the usb_host_endpoint
structure being pointed to is stored permanently in udev-&gt;ep0; it
doesn't get deallocated until the entire usb_device structure does.

Reported-and-tested-by: syzbot+db339689b2101f6f6071@syzkaller.appspotmail.com
Signed-off-by: Alan Stern &lt;stern@rowland.harvard.edu&gt;

Link: https://lore.kernel.org/r/Pine.LNX.4.44L0.2005011558590.903-100000@netrider.rowland.org
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>USB: core: Fix free-while-in-use bug in the USB S-Glibrary</title>
<updated>2020-04-16T12:46:00+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=056ad39ee9253873522f6469c3364964a322912b'/>
<id>056ad39ee9253873522f6469c3364964a322912b</id>
<content type='text'>
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;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
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;
</pre>
</div>
</content>
</entry>
<entry>
<title>usb: core: Add ACPI support for USB interface devices</title>
<updated>2020-03-24T12:38:51+00:00</updated>
<author>
<name>Andy Shevchenko</name>
<email>andriy.shevchenko@linux.intel.com</email>
</author>
<published>2020-03-24T10:09:23+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=a599a0fb629a61ef0c8c47312152866d24faeaff'/>
<id>a599a0fb629a61ef0c8c47312152866d24faeaff</id>
<content type='text'>
Currently on ACPI-enabled systems the USB interface device has no link to
the actual firmware node and thus drivers may not parse additional information
given in the table. The new feature, proposed here, allows to pass properties
or other information to the drivers.

The ACPI companion of the device has to be set for USB interface devices
to achieve above. Use ACPI_COMPANION_SET macro to set this.

Note, OF already does link of_node and this is the same for ACPI case.

Signed-off-by: Andy Shevchenko &lt;andriy.shevchenko@linux.intel.com&gt;
Reviewed-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Link: https://lore.kernel.org/r/20200324100923.8332-1-andriy.shevchenko@linux.intel.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>
Currently on ACPI-enabled systems the USB interface device has no link to
the actual firmware node and thus drivers may not parse additional information
given in the table. The new feature, proposed here, allows to pass properties
or other information to the drivers.

The ACPI companion of the device has to be set for USB interface devices
to achieve above. Use ACPI_COMPANION_SET macro to set this.

Note, OF already does link of_node and this is the same for ACPI case.

Signed-off-by: Andy Shevchenko &lt;andriy.shevchenko@linux.intel.com&gt;
Reviewed-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Link: https://lore.kernel.org/r/20200324100923.8332-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
