Quoting the bug report:

Due to compiler optimization or CPU out-of-order execution, the
desc->length update can be reordered before the memmove. If this
happens, wdm_read() can see the new length and call copy_to_user() on
uninitialized memory. This also violates LKMM data race rules [1].

Fix it by using WRITE_ONCE and memory barriers.

Fixes: afba937e540c9 ("USB: CDC WDM driver")
Cc: stable <stable@kernel.org>
Signed-off-by: Oliver Neukum <oneukum@suse.com>
Closes: https://lore.kernel.org/linux-usb/CALbr=LbrUZn_cfp7CfR-7Z5wDTHF96qeuM=3fO2m-q4cDrnC4A@mail.gmail.com/
Reported-by: Gui-Dong Han <hanguidong02@gmail.com>
Reviewed-by: Gui-Dong Han <hanguidong02@gmail.com>
Link: https://patch.msgid.link/20260304130116.1721682-1-oneukum@suse.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The CH343 USB/serial adapter is as buggy as it is popular (very).
One of its quirks is that despite being capable of signalling a
BREAK condition, it doesn't advertise it.

This used to work nonetheless until 66aad7d8d3ec5 ("usb: cdc-acm:
return correct error code on unsupported break") applied some
reasonable restrictions, preventing breaks from being emitted on
devices that do not advertise CAP_BRK.

Add a quirk for this particular device, so that breaks can still
be produced on some of my machines attached to my console server.

Fixes: 66aad7d8d3ec5 ("usb: cdc-acm: return correct error code on unsupported break")
Signed-off-by: Marc Zyngier <maz@kernel.org>
Cc: stable <stable@kernel.org>
Cc: Oliver Neukum <oneukum@suse.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Oliver Neukum <oneukum@suse.com>
Link: https://patch.msgid.link/20260301124440.1192752-1-maz@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The usbtmc driver accepts timeout values specified by the user in an
ioctl command, and uses these timeouts for some usb_bulk_msg() calls.
Since the user can specify arbitrarily long timeouts and
usb_bulk_msg() uses unkillable waits, call usb_bulk_msg_killable()
instead to avoid the possibility of the user hanging a kernel thread
indefinitely.

Reported-by: syzbot+25ba18e2c5040447585d@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/linux-usb/8e1c7ac5-e076-44b0-84b8-1b34b20f0ae1@suse.com/T/#t
Tested-by: syzbot+25ba18e2c5040447585d@syzkaller.appspotmail.com
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Fixes: 048c6d88a021 ("usb: usbtmc: Add ioctls to set/get usb timeout")
CC: stable@vger.kernel.org
Link: https://patch.msgid.link/81c6fc24-0607-40f1-8c20-5270dab2fad5@rowland.harvard.edu
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This was done entirely with mindless brute force, using

    git grep -l '\<k[vmz]*alloc_objs*(.*, GFP_KERNEL)' |
        xargs sed -i 's/\(alloc_objs*(.*\), GFP_KERNEL)/\1)/'

to convert the new alloc_obj() users that had a simple GFP_KERNEL
argument to just drop that argument.

Note that due to the extreme simplicity of the scripting, any slightly
more complex cases spread over multiple lines would not be triggered:
they definitely exist, but this covers the vast bulk of the cases, and
the resulting diff is also then easier to check automatically.

For the same reason the 'flex' versions will be done as a separate
conversion.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

This is the result of running the Coccinelle script from
scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to
avoid scalar types (which need careful case-by-case checking), and
instead replace kmalloc-family calls that allocate struct or union
object instances:

Single allocations:	kmalloc(sizeof(TYPE), ...)
are replaced with:	kmalloc_obj(TYPE, ...)

Array allocations:	kmalloc_array(COUNT, sizeof(TYPE), ...)
are replaced with:	kmalloc_objs(TYPE, COUNT, ...)

Flex array allocations:	kmalloc(struct_size(PTR, FAM, COUNT), ...)
are replaced with:	kmalloc_flex(*PTR, FAM, COUNT, ...)

(where TYPE may also be *VAR)

The resulting allocations no longer return "void *", instead returning
"TYPE *".

Signed-off-by: Kees Cook <kees@kernel.org>

The spec requires at least one interface respectively country.
It allows multiple ones. This needs to be clearly said in the UAPI.
This is subject to sanity checking in cdc_parse_cdc_header(), thus
we can trust the length.

Signed-off-by: Oliver Neukum <oneukum@suse.com>
Link: https://patch.msgid.link/20251111134641.4118827-1-oneukum@suse.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The local variable 'res' is only used to temporary store the results of
calling copy_from_user() and copy_to_user(). Use the results directly
and remove the local variable.

Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Link: https://lore.kernel.org/r/20250918151328.331015-1-thorsten.blum@linux.dev
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Use min_t() to improve usblp_read() and avoid calculating
'avail - usblp->readcount' twice. Use min_t(ssize_t,,) instead of min()
to avoid a signedness error.

Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Link: https://lore.kernel.org/r/20250829173713.56222-1-thorsten.blum@linux.dev
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Pull USB / Thunderbolt updates from Greg KH:
 "Here is the big set of USB and Thunderbolt driver changes for
  6.17-rc1.

  Lots of little things in here, mostly all small cleanups and updates,
  no major new features this development cycle. Stuff included in here
  is:

   - xhci minor tweaks for error handling

   - typec minor updates and a driver update

   - gadget driver api cleanups

   - unused function removals

   - unbind memory leak fixes

   - a few new device ids added

   - a few new devices supported for some drivers

   - other minor cleanups and changes

  All of these have been in linux-next with no reported issues, with the
  leak fixes being in the shortest amount of time, but they are
  'obviously correct' :)"

* tag 'usb-6.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb: (100 commits)
  usb: musb: omap2430: clean up probe error handling
  usb: musb: omap2430: fix device leak at unbind
  usb: gadget: udc: renesas_usb3: fix device leak at unbind
  usb: dwc3: meson-g12a: fix device leaks at unbind
  usb: dwc3: imx8mp: fix device leak at unbind
  usb: musb: omap2430: enable compile testing
  usb: gadget: udc: renesas_usb3: drop unused module alias
  usb: xhci: print xhci->xhc_state when queue_command failed
  usb: atm: cxacru: Merge cxacru_upload_firmware() into cxacru_heavy_init()
  USB: serial: option: add Foxconn T99W709
  usb: core: add urb->sgt parameter description
  thunderbolt: Fix copy+paste error in match_service_id()
  usb: typec: ucsi: Update power_supply on power role change
  usb: typec: ucsi: psy: Set current max to 100mA for BC 1.2 and Default
  usb: typec: fusb302: cache PD RX state
  usb: typec: ucsi: yoga-c630: add DRM dependency
  usb: gadget : fix use-after-free in composite_dev_cleanup()
  usb: chipidea: imx: Add a missing blank line
  usb: gadget: f_uac1: replace scnprintf() with sysfs_emit()
  usb: usblp: clean up assignment inside if conditions
  ...

This patch cleans up a few cases where assignments were made
inside of if conditions, like

if ((rv = func()) < 0)

into two lines, to improve readability and be more in-line with
Linux kernel coding style. It also cleans up checkpatch warnings
like:

ERROR: do not use assignment in if condition

No functional change, just a style and maintainability fix.

Signed-off-by: Darshan Rathod <darshan.rathod@siqol.com>
Link: https://lore.kernel.org/r/20250718091045.264129-1-darshan.rathod@siqol.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>