Since resplen and respoffs are signed integers sufficiently
large values of unsigned int len and offset members of RNDIS
response will result in negative values of prior variables.
This may be utilized to bypass implemented security checks
to either extract memory contents by manipulating offset or
overflow the data buffer via memcpy by manipulating both
offset and len.

Additionally assure that sum of resplen and respoffs does not
overflow so buffer boundaries are kept.

Fixes: 80f8c5b4 ("rndis_wlan: copy only useful data from rndis_command respond")
Signed-off-by: Szymon Heidrich <szymon.heidrich@gmail.com>
Reviewed-by: Alexander Duyck <alexanderduyck@fb.com>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/20230111175031.7049-1-szymon.heidrich@gmail.com