From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 79639EEB566 for ; Fri, 8 Sep 2023 18:24:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238305AbjIHSYj (ORCPT ); Fri, 8 Sep 2023 14:24:39 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47316 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344847AbjIHSX2 (ORCPT ); Fri, 8 Sep 2023 14:23:28 -0400 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0B40646BB; Fri, 8 Sep 2023 11:21:07 -0700 (PDT) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 36F9EC433BB; Fri, 8 Sep 2023 18:20:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1694197255; bh=fIfKdBdr2Qpawe7pAyCT7Sde+wM5scvw2iRmX6onw6w=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Ap/Rpq7gOPgG2bzcUO2WHSmP3y6+PLgYfATFc/9vr3Riqu/+dFThcSaOzCdjpSf/g EpPvew+CnDS1MWmIdnNv7eyjCmXs/Zao/mJoR+LIJmruJlPgUk7Wb+pLPjz6fNwgd1 4eGD+ZgD/BJO/yYtC80ZAfFb3X2mG6pgLqRfc+2yGeDwH/J6VpDZrZfxN/sahCgcwW u33yvcJclOqQBinXlXbPpo5AvYcCceVD8luI35tL/HradkD5eFv7g2fYF13E/ZY7Is 9VqrJ/2PeXfOqreI76Ta7CvurohXt3t1xqbAC0RsKUlzBoBgRMZqR1VCADtyeCdwQi g8EScGUj8+9Ug== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Dmitry Antipov , Brian Norris , Kalle Valo , Sasha Levin , linux-wireless@vger.kernel.org Subject: [PATCH AUTOSEL 5.4 03/10] wifi: mwifiex: fix fortify warning Date: Fri, 8 Sep 2023 14:20:37 -0400 Message-Id: <20230908182046.3460968-3-sashal@kernel.org> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20230908182046.3460968-1-sashal@kernel.org> References: <20230908182046.3460968-1-sashal@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 5.4.256 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Dmitry Antipov [ Upstream commit dcce94b80a954a8968ff29fafcfb066d6197fa9a ] When compiling with gcc 13.1 and CONFIG_FORTIFY_SOURCE=y, I've noticed the following: In function ‘fortify_memcpy_chk’, inlined from ‘mwifiex_construct_tdls_action_frame’ at drivers/net/wireless/marvell/mwifiex/tdls.c:765:3, inlined from ‘mwifiex_send_tdls_action_frame’ at drivers/net/wireless/marvell/mwifiex/tdls.c:856:6: ./include/linux/fortify-string.h:529:25: warning: call to ‘__read_overflow2_field’ declared with attribute warning: detected read beyond size of field (2nd parameter); maybe use struct_group()? [-Wattribute-warning] 529 | __read_overflow2_field(q_size_field, size); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ The compiler actually complains on: memmove(pos + ETH_ALEN, &mgmt->u.action.category, sizeof(mgmt->u.action.u.tdls_discover_resp)); and it happens because the fortification logic interprets this as an attempt to overread 1-byte 'u.action.category' member of 'struct ieee80211_mgmt'. To silence this warning, it's enough to pass an address of 'u.action' itself instead of an address of its first member. This also fixes an improper usage of 'sizeof()'. Since 'skb' is extended with 'sizeof(mgmt->u.action.u.tdls_discover_resp) + 1' bytes (where 1 is actually 'sizeof(mgmt->u.action.category)'), I assume that the same number of bytes should be copied. Suggested-by: Brian Norris Signed-off-by: Dmitry Antipov Reviewed-by: Brian Norris Signed-off-by: Kalle Valo Link: https://lore.kernel.org/r/20230629085115.180499-2-dmantipov@yandex.ru Signed-off-by: Sasha Levin --- drivers/net/wireless/marvell/mwifiex/tdls.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/drivers/net/wireless/marvell/mwifiex/tdls.c b/drivers/net/wireless/marvell/mwifiex/tdls.c index f8f282ce39bd4..17f8379351923 100644 --- a/drivers/net/wireless/marvell/mwifiex/tdls.c +++ b/drivers/net/wireless/marvell/mwifiex/tdls.c @@ -734,6 +734,7 @@ mwifiex_construct_tdls_action_frame(struct mwifiex_private *priv, int ret; u16 capab; struct ieee80211_ht_cap *ht_cap; + unsigned int extra; u8 radio, *pos; capab = priv->curr_bss_params.bss_descriptor.cap_info_bitmap; @@ -752,7 +753,10 @@ mwifiex_construct_tdls_action_frame(struct mwifiex_private *priv, switch (action_code) { case WLAN_PUB_ACTION_TDLS_DISCOVER_RES: - skb_put(skb, sizeof(mgmt->u.action.u.tdls_discover_resp) + 1); + /* See the layout of 'struct ieee80211_mgmt'. */ + extra = sizeof(mgmt->u.action.u.tdls_discover_resp) + + sizeof(mgmt->u.action.category); + skb_put(skb, extra); mgmt->u.action.category = WLAN_CATEGORY_PUBLIC; mgmt->u.action.u.tdls_discover_resp.action_code = WLAN_PUB_ACTION_TDLS_DISCOVER_RES; @@ -761,8 +765,7 @@ mwifiex_construct_tdls_action_frame(struct mwifiex_private *priv, mgmt->u.action.u.tdls_discover_resp.capability = cpu_to_le16(capab); /* move back for addr4 */ - memmove(pos + ETH_ALEN, &mgmt->u.action.category, - sizeof(mgmt->u.action.u.tdls_discover_resp)); + memmove(pos + ETH_ALEN, &mgmt->u.action, extra); /* init address 4 */ eth_broadcast_addr(pos); -- 2.40.1