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 B3D37EEB560 for ; Fri, 8 Sep 2023 18:19:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1343880AbjIHSTQ (ORCPT ); Fri, 8 Sep 2023 14:19:16 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41810 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1343847AbjIHSSk (ORCPT ); Fri, 8 Sep 2023 14:18:40 -0400 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F12B926B8; Fri, 8 Sep 2023 11:18:08 -0700 (PDT) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5CBDCC433CB; Fri, 8 Sep 2023 18:16:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1694196973; bh=xIYj9x7VhSQtAwPzUkxA3IumAGJ7hoT0f59ISFAR3/U=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Hr6rrmvrgB88iI1Dmi7SKmffctUER/nc4JONhKzuNtoS3C6ennAqdRsOtfM3JRcAE 0Qxfwd8hZpVQGMtFuRA7dqztxmlHQcqpK2ME+4cDrX2SIb89JMnsxadjVCgZ/88kYC LlUkwlKS6QYdY7jW9qENeSpd1PuTcdhRfvZDfxQm6jFkxy/X7ZftVDD3C8lsZIR/MF k3dUUylhYJBG1J5kAXaMFD/CzRDLYpI8Y6CzpNOQXNWqqHxkuntQ/DcB9w0u88tzoK JZK+DnOYbg+vN/VvB4EOjzxovmxC0IGyRSsz4uRQTqag49QLKhHVESFQd4BpFlhhtO JTF1LDR6Y6+0Q== 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 6.4 08/41] wifi: mwifiex: fix fortify warning Date: Fri, 8 Sep 2023 14:15:22 -0400 Message-Id: <20230908181555.3459640-8-sashal@kernel.org> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20230908181555.3459640-1-sashal@kernel.org> References: <20230908181555.3459640-1-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 6.4.15 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-wireless@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