USB: gadget: u_f: Unbreak offset calculation in VLAs

Inadvertently the commit b1cd1b65afba ("USB: gadget: u_f: add overflow checks
to VLA macros") makes VLA macros to always return 0 due to different scope of
two variables of the same name. Obviously we need to have only one.

Fixes: b1cd1b65afba ("USB: gadget: u_f: add overflow checks to VLA macros")
Reported-by: Marek Szyprowski <m.szyprowski@samsung.com>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Brooke Basile <brookebasile@gmail.com>
Cc: stable <stable@kernel.org>
Link: https://lore.kernel.org/r/20200826192119.56450-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

USB: gadget: u_f: add overflow checks to VLA macros

size can potentially hold an overflowed value if its assigned expression
is left unchecked, leading to a smaller than needed allocation when
vla_group_size() is used by callers to allocate memory.
To fix this, add a test for saturation before declaring variables and an
overflow check to (n) * sizeof(type).
If the expression results in overflow, vla_group_size() will return SIZE_MAX.

Reported-by: Ilja Van Sprundel <ivansprundel@ioactive.com>
Suggested-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Brooke Basile <brookebasile@gmail.com>
Acked-by: Felipe Balbi <balbi@kernel.org>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: Change Andrzej Pietrasiewicz's e-mail address

My @samusung.com address is going to cease existing soon, so change it to
an address which can actually be used to contact me.

Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

USB: gadget: f_midi: fixing a possible double-free in f_midi

It looks like there is a possibility of a double-free vulnerability on an
error path of the f_midi_set_alt function in the f_midi driver. If the
path is feasible then free_ep_req gets called twice:

req->complete = f_midi_complete;
err = usb_ep_queue(midi->out_ep, req, GFP_ATOMIC);
=> ...
usb_gadget_giveback_request
=>
f_midi_complete (CALLBACK)
(inside f_midi_complete, for various cases of status)
free_ep_req(ep, req); // first kfree
if (err) {
ERROR(midi, "%s: couldn't enqueue request: %d\n",
midi->out_ep->name, err);
free_ep_req(midi->out_ep, req); // second kfree
return err;
}

The double-free possibility was introduced with commit ad0d1a058eac
("usb: gadget: f_midi: fix leak on failed to enqueue out requests").

Found by MOXCAFE tool.

Signed-off-by: Tuba Yavuz <tuba@ece.ufl.edu>
Fixes: ad0d1a058eac ("usb: gadget: f_midi: fix leak on failed to enqueue out requests")
Acked-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

USB: gadget: Remove redundant license text

Now that the SPDX tag is in all USB files, that identifies the license
in a specific and legally-defined manner. So the extra GPL text wording
can be removed as it is no longer needed at all.

This is done on a quest to remove the 700+ different ways that files in
the kernel describe the GPL license text. And there's unneeded stuff
like the address (sometimes incorrect) for the FSF which is never
needed.

No copyright headers or other non-license-description text was removed.

Acked-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

USB: add SPDX identifiers to all remaining files in drivers/usb/

It's good to have SPDX identifiers in all files to make it easier to
audit the kernel tree for correct licenses.

Update the drivers/usb/ and include/linux/usb* files with the correct
SPDX license identifier based on the license text in the file itself.
The SPDX identifier is a legally binding shorthand, which can be used
instead of the full boiler plate text.

This work is based on a script and data from Thomas Gleixner, Philippe
Ombredanne, and Kate Stewart.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Kate Stewart <kstewart@linuxfoundation.org>
Cc: Philippe Ombredanne <pombredanne@nexb.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Acked-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: remove useless parameter in alloc_ep_req()

The default_length parameter of alloc_ep_req was not really necessary
and gadget drivers would almost always create an inline function to pass
the same value to len and default_len.

This patch removes that parameter and updates all calls to alloc_ep_req() to
use the new API.

Signed-off-by: Felipe F. Tonello <eu@felipetonello.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

usb: gadget: align buffer size when allocating for OUT endpoint

Using usb_ep_align() makes sure that the buffer size for OUT endpoints is
always aligned with wMaxPacketSize (512 usually). This makes sure
that no buffer has the wrong size, which can cause nasty bugs.

Signed-off-by: Felipe F. Tonello <eu@felipetonello.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

usb: gadget: change len to size_t on alloc_ep_req()

Length of buffers should be of type size_t whenever possible. Altough
recommended, this change has no real practical change, unless a driver has a
uses a huge or negative buffer size - it might help find these bugs.

Signed-off-by: Felipe F. Tonello <eu@felipetonello.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

usb: gadget: define free_ep_req as universal function

This function is shared between gadget functions, so this avoid unnecessary
duplicated code and potentially avoid memory leaks.

Reviewed-by: Robert Baldyga <r.baldyga@samsung.com>
Signed-off-by: Felipe F. Tonello <eu@felipetonello.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

usb: gadget: FunctionFS: share VLA macros with all usb gadget files

Variable Length Array macros allow portable (compilable with both gcc
and clang) way of allocating a number of structures using a single
memory chunk. They can be useful for files other than f_fs.c,
so move them to a header file.

Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
Acked-by: Michal Nazarewicz <mina86@mina86.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

usb: gadget: factor out alloc_ep_req

alloc_ep_req() is a function repeated in several modules.
Make a common implementation and use it.

Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Acked-by: Michal Nazarewicz <mina86@mina86.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>