From 19cc6d98a6ad6899ccc70cffb39365e7e7cdca93 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Wed, 11 Jan 2017 15:35:25 +0100 Subject: [PATCH] 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 Signed-off-by: Johannes Berg Signed-off-by: Willy Tarreau --- include/net/iw_handler.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/include/net/iw_handler.h b/include/net/iw_handler.h index 5d5a6a4732ef..5af07a1ab0c2 100644 --- a/include/net/iw_handler.h +++ b/include/net/iw_handler.h @@ -551,7 +551,8 @@ iwe_stream_add_point(struct iw_request_info *info, char *stream, char *ends, 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; -- 2.20.1