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 837C6EEB560 for ; Fri, 8 Sep 2023 18:23:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241027AbjIHSXq (ORCPT ); Fri, 8 Sep 2023 14:23:46 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57170 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344358AbjIHSWE (ORCPT ); Fri, 8 Sep 2023 14:22:04 -0400 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 96E833591; Fri, 8 Sep 2023 11:19:36 -0700 (PDT) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A7164C433BA; Fri, 8 Sep 2023 18:19:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1694197171; bh=xIYj9x7VhSQtAwPzUkxA3IumAGJ7hoT0f59ISFAR3/U=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=f3bt7wMJVKCMwfNu2+CR6MgbTh/c1sCf/gTnHl5mSLUzPFhTJO5YgLjq0hwXAmQvp kwrVaC2VUa/cRnfA1rd3oO4oJN1EWPV9KJRSZ+vK+miPilsjZBpben1qRp75HPM2qL UNjVpcpeL5Dl7BvD4eYEllUz8oaOj/Tqf54gq0XZwgh4qHLb67pLT6yTe+9pQ7MjFB +FSD9YSALhH9l62bp5z0Q5v8oM0Ga/ComJxhwe/dC64soMfTA6rOWSsVCBDctrxvQO ibzwdmuyPG9rODuvVi9NpKeEz4H/U3Bzl78UNmsYZeQ7hH9BLSX4N3SkKoXJJTlVGl 8+1GCL4NPLfbw== 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 5.15 05/15] wifi: mwifiex: fix fortify warning Date: Fri, 8 Sep 2023 14:19:08 -0400 Message-Id: <20230908181920.3460520-5-sashal@kernel.org> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20230908181920.3460520-1-sashal@kernel.org> References: <20230908181920.3460520-1-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 5.15.131 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 97bb87c3676bb..6c60621b6cccb 100644 --- a/drivers/net/wireless/marvell/mwifiex/tdls.c +++ b/drivers/net/wireless/marvell/mwifiex/tdls.c @@ -735,6 +735,7 @@ 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; @@ -753,7 +754,10 @@ 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; @@ -762,8 +766,7 @@ 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