From patchwork Fri Jan 17 15:48:39 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Robin Murphy X-Patchwork-Id: 11339495 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 47CEC138D for ; Fri, 17 Jan 2020 15:48:50 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 21D8A2072E for ; Fri, 17 Jan 2020 15:48:50 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="MEVSGzFu" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 21D8A2072E Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:Message-Id:Date:Subject:To :From:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References: List-Owner; bh=xuHlXOYsUDM0nYZS4K+/doHbLXC3EXMCO/gv94c4ZXs=; b=MEVSGzFucq/f6e hILwabOcIQdQJKx+f7o273sYE2hvD6e3F9voogyu7DhHGd6ejLYeDffePO5EiULaUw2ECZB9vO7MO 5mpYqNVe1DkJSxpkRrVgmIGrCfCfw4URE7tW7oX43+0/WV+aDGG7op6NiD1GhuCVr8nHb0klyztvf XfRZ2Otc6E6pIlOQ1ttvTOblVh/41jDTwWdmaLitlHSGaeI23yp1rvuooGHnYg7KwNNmKs+aeEGHM v1NPddBW8ia/0/Sz18qQpvcLNi6UsWX2wLRYCn/aQ4aT8dQCS9rfglVw10BUttj7i472XXXRGJohA YHazmkDHSD0iu+U5fRhw==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1isTrc-0006mJ-8X; Fri, 17 Jan 2020 15:48:48 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1isTrY-0006ld-Sy for linux-arm-kernel@lists.infradead.org; Fri, 17 Jan 2020 15:48:46 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id C50BF113E; Fri, 17 Jan 2020 07:48:42 -0800 (PST) Received: from e121345-lin.cambridge.arm.com (e121345-lin.cambridge.arm.com [10.1.196.37]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 319EF3F718; Fri, 17 Jan 2020 07:48:42 -0800 (PST) From: Robin Murphy To: will@kernel.org, catalin.marinas@arm.com Subject: [PATCH] arm64: csum: Fix pathological zero-length calls Date: Fri, 17 Jan 2020 15:48:39 +0000 Message-Id: X-Mailer: git-send-email 2.23.0.dirty MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200117_074844_980715_1AEC97C6 X-CRM114-Status: GOOD ( 13.43 ) X-Spam-Score: 0.0 (/) X-Spam-Report: SpamAssassin version 3.4.2 on bombadil.infradead.org summary: Content analysis details: (0.0 points) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 RCVD_IN_DNSWL_NONE RBL: Sender listed at https://www.dnswl.org/, no trust [217.140.110.172 listed in list.dnswl.org] 0.0 SPF_HELO_NONE SPF: HELO does not publish an SPF Record -0.0 SPF_PASS SPF: sender matches SPF record X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-arm-kernel@lists.infradead.org Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org In validating the checksumming results of the new routine, I sadly neglected to test its not-checksumming results. Thus it slipped through that the one case where @buff is already dword-aligned and @len = 0 manages to defeat the tail-masking logic and behave as if @len = 8. For a zero length it doesn't make much sense to deference @buff anyway, so just add an early return (which has essentially zero impact on performance). Signed-off-by: Robin Murphy --- I'm still trying to make sense of the CKI UDP fails, but I've re-tested against the generic routine and this was the only thing that fell out. arch/arm64/lib/csum.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/arm64/lib/csum.c b/arch/arm64/lib/csum.c index 847eb725ce09..1f82c66b32ea 100644 --- a/arch/arm64/lib/csum.c +++ b/arch/arm64/lib/csum.c @@ -20,6 +20,9 @@ unsigned int do_csum(const unsigned char *buff, int len) const u64 *ptr; u64 data, sum64 = 0; + if (unlikely(len == 0)) + return 0; + offset = (unsigned long)buff & 7; /* * This is to all intents and purposes safe, since rounding down cannot