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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,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 C93D9C33CB3 for ; Thu, 16 Jan 2020 17:23:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8CAF9214AF for ; Thu, 16 Jan 2020 17:23:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579195438; bh=Eq9RVcXC8HyF9NPP1DA4CFc8o7TE6r/C5AI3H7ITmvQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=kUaSiKoOSySVn8wdbIct9o42oQ3UeBG3Rxr93Y32Q3qUeklXGkD8ri2QUNFfhYSDo wnUYA6/58EKiiuBBSNNlhb1s3Mo7AxsMY8ajIZIE1Wb9bkqcApoTvh/bE1+kQL/IE/ 6cKIlzF3mLAHoCjucA5acYeaysvoI/pObXy+Koxw= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2391304AbgAPRX5 (ORCPT ); Thu, 16 Jan 2020 12:23:57 -0500 Received: from mail.kernel.org ([198.145.29.99]:57398 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390652AbgAPRNI (ORCPT ); Thu, 16 Jan 2020 12:13:08 -0500 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 52ADE246A3; Thu, 16 Jan 2020 17:13:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579194788; bh=Eq9RVcXC8HyF9NPP1DA4CFc8o7TE6r/C5AI3H7ITmvQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=JmLon4rdYPCFqydEoF5rPrOhdfHittVmDJnKQe/mk/MOrCo9tFcRjkutDhzjOwHkB sApDGbD+405nmSKEyGAnLtOC/14TRPbSgV57MuICbats1OnqdQmDIldVL2Dl7Rkb2X PxmaF8uAsZClNaGa/AwTtBxVvve3IiMPPkN0ox6o= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Magnus Karlsson , Kal Cutter Conley , Alexei Starovoitov , Jonathan Lemon , Sasha Levin , netdev@vger.kernel.org, bpf@vger.kernel.org Subject: [PATCH AUTOSEL 4.19 602/671] xsk: Fix registration of Rx-only sockets Date: Thu, 16 Jan 2020 12:04:00 -0500 Message-Id: <20200116170509.12787-339-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200116170509.12787-1-sashal@kernel.org> References: <20200116170509.12787-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Magnus Karlsson [ Upstream commit 2afd23f78f39da84937006ecd24aa664a4ab052b ] Having Rx-only AF_XDP sockets can potentially lead to a crash in the system by a NULL pointer dereference in xsk_umem_consume_tx(). This function iterates through a list of all sockets tied to a umem and checks if there are any packets to send on the Tx ring. Rx-only sockets do not have a Tx ring, so this will cause a NULL pointer dereference. This will happen if you have registered one or more Rx-only sockets to a umem and the driver is checking the Tx ring even on Rx, or if the XDP_SHARED_UMEM mode is used and there is a mix of Rx-only and other sockets tied to the same umem. Fixed by only putting sockets with a Tx component on the list that xsk_umem_consume_tx() iterates over. Fixes: ac98d8aab61b ("xsk: wire upp Tx zero-copy functions") Reported-by: Kal Cutter Conley Signed-off-by: Magnus Karlsson Signed-off-by: Alexei Starovoitov Acked-by: Jonathan Lemon Link: https://lore.kernel.org/bpf/1571645818-16244-1-git-send-email-magnus.karlsson@intel.com Signed-off-by: Sasha Levin --- net/xdp/xdp_umem.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/net/xdp/xdp_umem.c b/net/xdp/xdp_umem.c index d9117ab035f7..556a649512b6 100644 --- a/net/xdp/xdp_umem.c +++ b/net/xdp/xdp_umem.c @@ -23,6 +23,9 @@ void xdp_add_sk_umem(struct xdp_umem *umem, struct xdp_sock *xs) { unsigned long flags; + if (!xs->tx) + return; + spin_lock_irqsave(&umem->xsk_list_lock, flags); list_add_rcu(&xs->list, &umem->xsk_list); spin_unlock_irqrestore(&umem->xsk_list_lock, flags); @@ -32,6 +35,9 @@ void xdp_del_sk_umem(struct xdp_umem *umem, struct xdp_sock *xs) { unsigned long flags; + if (!xs->tx) + return; + spin_lock_irqsave(&umem->xsk_list_lock, flags); list_del_rcu(&xs->list); spin_unlock_irqrestore(&umem->xsk_list_lock, flags); -- 2.20.1