wext: handle NULL extra data in iwe_stream_add_point better
authorArnd Bergmann <arnd@arndb.de>
Wed, 11 Jan 2017 14:35:25 +0000 (15:35 +0100)
committerJohannes Berg <johannes.berg@intel.com>
Thu, 12 Jan 2017 09:15:00 +0000 (10:15 +0100)
commit93be2b74279c15c2844684b1a027fdc71dd5d9bf
tree432054ca6bab96b982f47607e2e7835bcd9a9a81
parent7acec26cec5aa75e0dc54da1fb0b1f8acf575273
wext: handle NULL extra data in iwe_stream_add_point better

gcc-7 complains that wl3501_cs passes NULL into a function that
then uses the argument as the input for memcpy:

drivers/net/wireless/wl3501_cs.c: In function 'wl3501_get_scan':
include/net/iw_handler.h:559:3: error: argument 2 null where non-null expected [-Werror=nonnull]
   memcpy(stream + point_len, extra, iwe->u.data.length);

This works fine here because iwe->u.data.length is guaranteed to be 0
and the memcpy doesn't actually have an effect.

Making the length check explicit avoids the warning and should have
no other effect here.

Also check the pointer itself, since otherwise we get warnings
elsewhere in the code.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
include/net/iw_handler.h