tree 1d5d0434e25a913b14c4e1b01ed52dcfc1d80af8
parent b9d68cdce72d49c06c24fb2f5bee5673557b33ac
author Arnd Bergmann <arnd@arndb.de> 1484145325 +0100
committer Greg Kroah-Hartman <gregkh@linuxfoundation.org> 1502466574 -0700

wext: handle NULL extra data in iwe_stream_add_point better

commit 93be2b74279c15c2844684b1a027fdc71dd5d9bf upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>