From patchwork Fri Jun 23 15:23:59 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Arnd Bergmann X-Patchwork-Id: 695707 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 D4845EB64D7 for ; Fri, 23 Jun 2023 15:25:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232418AbjFWPZN (ORCPT ); Fri, 23 Jun 2023 11:25:13 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42078 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232211AbjFWPZN (ORCPT ); Fri, 23 Jun 2023 11:25:13 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 313621BF2; Fri, 23 Jun 2023 08:25:12 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id B7A2761AA0; Fri, 23 Jun 2023 15:25:11 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 730FFC433C8; Fri, 23 Jun 2023 15:25:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1687533911; bh=PWzWmQ+cBgJK6M6TA5MtMDmO0z6eE5AOkMWX2YVaO2k=; h=From:To:Cc:Subject:Date:From; b=P5hRm+79D+2sZ4kgfzfW91OywrM3XnOisdudNi2GlRMtyg5UH0fJKk2zIoCvyQc0P OwxUG8xC5hN6tuNUjuWTNRak3gq/OOfYS97/iZCng3xsnGxJBupj1nQL4aFhvctmTl augdY8OVO3DMh8cmyA8rxuEBFe/VRRgZQOTlmPsUAmYmcvKAUXHz+EIfDEAFO5yorG jOArBFZOJ+JaLhy4odrlwAyqdOyzmGfQemDAzuZZPVMFdSw6hqjMbX4XQiLJ8l/Zjj z3IgMXZdxB3oDlwbQ0XHp6Lf1srAPR+fS7bEartCAlVGgVq1o5ryKAW6kT7e8BK7jn CoDA9RnFTW+uA== From: Arnd Bergmann To: Christian Lamparter , Kalle Valo , Kees Cook , Johannes Berg Cc: Arnd Bergmann , linux-wireless@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 1/2] carl9170: re-fix fortified-memset warning Date: Fri, 23 Jun 2023 17:23:59 +0200 Message-Id: <20230623152443.2296825-1-arnd@kernel.org> X-Mailer: git-send-email 2.39.2 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org From: Arnd Bergmann The carl9170_tx_release() function sometimes triggers a fortified-memset warning in my randconfig builds: In file included from include/linux/string.h:254, from drivers/net/wireless/ath/carl9170/tx.c:40: In function 'fortify_memset_chk', inlined from 'carl9170_tx_release' at drivers/net/wireless/ath/carl9170/tx.c:283:2, inlined from 'kref_put' at include/linux/kref.h:65:3, inlined from 'carl9170_tx_put_skb' at drivers/net/wireless/ath/carl9170/tx.c:342:9: include/linux/fortify-string.h:493:25: error: call to '__write_overflow_field' declared with attribute warning: detected write beyond size of field (1st parameter); maybe use struct_group()? [-Werror=attribute-warning] 493 | __write_overflow_field(p_size_field, size); Kees previously tried to avoid this by using memset_after(), but it seems this does not fully address the problem. I noticed that the memset_after() here is done on a different part of the union (status) than the original cast was from (rate_driver_data), which may confuse the compiler. Unfortunately, the memset_after() trick does not work on driver_rates[] because that is part of an anonymous struct, and I could not get struct_group() to do this either. Using two separate memset() calls on the two members does address the warning though. Fixes: fb5f6a0e8063b ("mac80211: Use memset_after() to clear tx status") Signed-off-by: Arnd Bergmann Reviewed-by: Kees Cook --- drivers/net/wireless/ath/carl9170/tx.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/net/wireless/ath/carl9170/tx.c b/drivers/net/wireless/ath/carl9170/tx.c index 6bb9aa2bfe654..88ef6e023f826 100644 --- a/drivers/net/wireless/ath/carl9170/tx.c +++ b/drivers/net/wireless/ath/carl9170/tx.c @@ -280,7 +280,8 @@ static void carl9170_tx_release(struct kref *ref) * carl9170_tx_fill_rateinfo() has filled the rate information * before we get to this point. */ - memset_after(&txinfo->status, 0, rates); + memset(&txinfo->pad, 0, sizeof(txinfo->pad)); + memset(&txinfo->rate_driver_data, 0, sizeof(txinfo->rate_driver_data)); if (atomic_read(&ar->tx_total_queued)) ar->tx_schedule = true;