4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Arnd Bergmann <arnd@xxxxxxxx> 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@xxxxxxxx> Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- include/net/iw_handler.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/include/net/iw_handler.h +++ b/include/net/iw_handler.h @@ -556,7 +556,8 @@ iwe_stream_add_point(struct iw_request_i memcpy(stream + lcp_len, ((char *) &iwe->u) + IW_EV_POINT_OFF, IW_EV_POINT_PK_LEN - IW_EV_LCP_PK_LEN); - memcpy(stream + point_len, extra, iwe->u.data.length); + if (iwe->u.data.length && extra) + memcpy(stream + point_len, extra, iwe->u.data.length); stream += event_len; } return stream;