d3136b7970
[ Upstream commit 89ff3dfac604614287ad5aad9370c3f984ea3f4b ]
The embedded struct cdev does not have its lifetime correctly tied to
the enclosing struct f_hidg, so there is a use-after-free if /dev/hidgN
is held open while the gadget is deleted.
This can readily be replicated with libusbgx's example programs (for
conciseness - operating directly via configfs is equivalent):
gadget-hid
exec 3<> /dev/hidg0
gadget-vid-pid-remove
exec 3<&-
Pull the existing device up in to struct f_hidg and make use of the
cdev_device_{add,del}() helpers. This changes the lifetime of the
device object to match struct f_hidg, but note that it is still added
and deleted at the same time.
Fixes: 71adf1189469 ("USB: gadget: add HID gadget driver")
Tested-by: Lee Jones <lee@kernel.org>
Reviewed-by: Andrzej Pietrasiewicz <andrzej.p@collabora.com>
Reviewed-by: Lee Jones <lee@kernel.org>
Signed-off-by: John Keeping <john@metanate.com>
Link: https://lore.kernel.org/r/20221122123523.3068034-2-john@metanate.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.