From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933903AbdKAV1u (ORCPT ); Wed, 1 Nov 2017 17:27:50 -0400 Received: from wtarreau.pck.nerim.net ([62.212.114.60]:35281 "EHLO 1wt.eu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934051AbdKAV1p (ORCPT ); Wed, 1 Nov 2017 17:27:45 -0400 From: Willy Tarreau To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, linux@roeck-us.net Cc: Arnd Bergmann , Johannes Berg , Willy Tarreau Subject: [PATCH 3.10 071/139] wext: handle NULL extra data in iwe_stream_add_point better Date: Wed, 1 Nov 2017 22:26:12 +0100 Message-Id: <1509571600-4858-22-git-send-email-w@1wt.eu> X-Mailer: git-send-email 2.8.0.rc2.1.gbe9624a In-Reply-To: <1509571600-4858-1-git-send-email-w@1wt.eu> References: <1509571159-4405-1-git-send-email-w@1wt.eu> <1509571600-4858-1-git-send-email-w@1wt.eu> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Arnd Bergmann 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 5d5a6a4..5af07a1 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; -- 2.8.0.rc2.1.gbe9624a