b216a39b32
[ Upstream commit b7abf78b7a6c4a29a6e0ba0bb883fe44a2f3d693 ]
The previous commit fixed handling of incomplete packets but broke error
handling: offsetof returns an unsigned value (size_t), but when compared
against the signed return value, the return value is interpreted as if
it were unsigned, so negative return values are never less than the
offset.
To make the code easier to read, calculate the minimal packet length
once and separately, and assign it to a signed int variable to eliminate
unsigned math and the need for type casts. It then becomes immediately
obvious how the actual data length is calculated and why the return
value cannot be less than the minimal length.
Fixes: 22d65765f211 ("HID: u2fzero: ignore incomplete packets without data")
Fixes: 42337b9d4d95 ("HID: add driver for U2F Zero built-in LED and RNG")
Signed-off-by: Andrej Shadura <andrew.shadura@collabora.co.uk>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
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.