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 A4507EB64DC for ; Mon, 19 Jun 2023 10:40:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230464AbjFSKkW (ORCPT ); Mon, 19 Jun 2023 06:40:22 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45586 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231996AbjFSKjm (ORCPT ); Mon, 19 Jun 2023 06:39:42 -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 09824E60 for ; Mon, 19 Jun 2023 03:39:36 -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 923A460B0D for ; Mon, 19 Jun 2023 10:39:35 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A9E5BC433C0; Mon, 19 Jun 2023 10:39:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1687171175; bh=WPIb16hqrlz61l0FQA8ADKcKMCDqMZD1I8OUcKmMBzs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=LeFzhQb5veau3G/OHXQANCcMkEfWxSHwf90k2dB90mLOETwO+zVvh2sTa64OM1934 Gn99PF3l9KDyKcH0GIaIVmc2oesejc5jaJtmDwvLeAaXjuaRLd1I9rbGKLqDFWVUw/ jvJOVryAGYHzAfH7w3JgJyohcDg5IhpKUD/FxUsM= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Vladimir Oltean , Simon Horman , Jakub Kicinski , Sasha Levin Subject: [PATCH 6.3 174/187] net: dsa: felix: fix taprio guard band overflow at 10Mbps with jumbo frames Date: Mon, 19 Jun 2023 12:29:52 +0200 Message-ID: <20230619102206.094132849@linuxfoundation.org> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230619102157.579823843@linuxfoundation.org> References: <20230619102157.579823843@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Vladimir Oltean [ Upstream commit 6ac7a27a8b07588497ed53dfd885df9c72bc67e0 ] The DEV_MAC_MAXLEN_CFG register contains a 16-bit value - up to 65535. Plus 2 * VLAN_HLEN (4), that is up to 65543. The picos_per_byte variable is the largest when "speed" is lowest - SPEED_10 = 10. In that case it is (1000000L * 8) / 10 = 800000. Their product - 52434400000 - exceeds 32 bits, which is a problem, because apparently, a multiplication between two 32-bit factors is evaluated as 32-bit before being assigned to a 64-bit variable. In fact it's a problem for any MTU value larger than 5368. Cast one of the factors of the multiplication to u64 to force the multiplication to take place on 64 bits. Issue found by Coverity. Fixes: 55a515b1f5a9 ("net: dsa: felix: drop oversized frames with tc-taprio instead of hanging the port") Signed-off-by: Vladimir Oltean Reviewed-by: Simon Horman Link: https://lore.kernel.org/r/20230613170907.2413559-1-vladimir.oltean@nxp.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- drivers/net/dsa/ocelot/felix_vsc9959.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/dsa/ocelot/felix_vsc9959.c b/drivers/net/dsa/ocelot/felix_vsc9959.c index dddb28984bdfc..841c5ebc1afaa 100644 --- a/drivers/net/dsa/ocelot/felix_vsc9959.c +++ b/drivers/net/dsa/ocelot/felix_vsc9959.c @@ -1263,7 +1263,7 @@ static void vsc9959_tas_guard_bands_update(struct ocelot *ocelot, int port) /* Consider the standard Ethernet overhead of 8 octets preamble+SFD, * 4 octets FCS, 12 octets IFG. */ - needed_bit_time_ps = (maxlen + 24) * picos_per_byte; + needed_bit_time_ps = (u64)(maxlen + 24) * picos_per_byte; dev_dbg(ocelot->dev, "port %d: max frame size %d needs %llu ps at speed %d\n", -- 2.39.2