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 X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 95E00C5518A for ; Wed, 22 Apr 2020 10:46:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 737762073A for ; Wed, 22 Apr 2020 10:46:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587552414; bh=dgsp2o5jhO3cVaLbl6yI7GcuL8xJF4PWHyAwkSBbIFo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=hMEgeEPtkHCqBQiZgvDH2JNVJylAUo3Q8HLHER8J0LlK622o+/J3vtVxBsoAyxJDo D5UamQZQ5kxK7fSSosvzXffifU78D5yMyG/wFy2U2XL5UfmAQQLQKFpDn2563g0sAd F5BvIvjTjG7isZcg4tIuuJR0jlKxlJAo/g2QOKSM= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728249AbgDVKQg (ORCPT ); Wed, 22 Apr 2020 06:16:36 -0400 Received: from mail.kernel.org ([198.145.29.99]:52316 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729691AbgDVKQb (ORCPT ); Wed, 22 Apr 2020 06:16:31 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 80D862076B; Wed, 22 Apr 2020 10:16:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587550591; bh=dgsp2o5jhO3cVaLbl6yI7GcuL8xJF4PWHyAwkSBbIFo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=kXbtkGXZBB1JVl7mlnU4ewxKblAmsa41iUXOTrUnbgvXxDzIsCO3njfgk+LUZNVA9 QfK2eutDTY5XNCi4CWzK5imk0zCeNdpddsskHyri+kl2EXTzhUxnVt8Ooc59YvJlfN nQJ9DZ98M/QMT68U0QyhV+nBspVQhqtHZjS+HeD4= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Bui Quang Minh , Magnus Karlsson , Daniel Borkmann Subject: [PATCH 5.4 014/118] xsk: Add missing check on user supplied headroom size Date: Wed, 22 Apr 2020 11:56:15 +0200 Message-Id: <20200422095033.911940986@linuxfoundation.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200422095031.522502705@linuxfoundation.org> References: <20200422095031.522502705@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Magnus Karlsson commit 99e3a236dd43d06c65af0a2ef9cb44306aef6e02 upstream. Add a check that the headroom cannot be larger than the available space in the chunk. In the current code, a malicious user can set the headroom to a value larger than the chunk size minus the fixed XDP headroom. That way packets with a length larger than the supported size in the umem could get accepted and result in an out-of-bounds write. Fixes: c0c77d8fb787 ("xsk: add user memory registration support sockopt") Reported-by: Bui Quang Minh Signed-off-by: Magnus Karlsson Signed-off-by: Daniel Borkmann Link: https://bugzilla.kernel.org/show_bug.cgi?id=207225 Link: https://lore.kernel.org/bpf/1586849715-23490-1-git-send-email-magnus.karlsson@intel.com Signed-off-by: Greg Kroah-Hartman --- net/xdp/xdp_umem.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) --- a/net/xdp/xdp_umem.c +++ b/net/xdp/xdp_umem.c @@ -343,7 +343,7 @@ static int xdp_umem_reg(struct xdp_umem u32 chunk_size = mr->chunk_size, headroom = mr->headroom; unsigned int chunks, chunks_per_page; u64 addr = mr->addr, size = mr->len; - int size_chk, err; + int err; if (chunk_size < XDP_UMEM_MIN_CHUNK_SIZE || chunk_size > PAGE_SIZE) { /* Strictly speaking we could support this, if: @@ -382,8 +382,7 @@ static int xdp_umem_reg(struct xdp_umem return -EINVAL; } - size_chk = chunk_size - headroom - XDP_PACKET_HEADROOM; - if (size_chk < 0) + if (headroom >= chunk_size - XDP_PACKET_HEADROOM) return -EINVAL; umem->address = (unsigned long)addr;