Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753135AbdHITrl (ORCPT ); Wed, 9 Aug 2017 15:47:41 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:46158 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752632AbdHITnp (ORCPT ); Wed, 9 Aug 2017 15:43:45 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Arnd Bergmann , Johannes Berg Subject: [PATCH 4.4 43/58] wext: handle NULL extra data in iwe_stream_add_point better Date: Wed, 9 Aug 2017 12:41:55 -0700 Message-Id: <20170809194148.200732108@linuxfoundation.org> X-Mailer: git-send-email 2.14.0 In-Reply-To: <20170809194146.501519882@linuxfoundation.org> References: <20170809194146.501519882@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1526 Lines: 45 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ 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: Greg Kroah-Hartman --- 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;