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=-3.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED autolearn=no 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 0D981CA9EB9 for ; Wed, 23 Oct 2019 23:03:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CB14220659 for ; Wed, 23 Oct 2019 23:03:51 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="spC33OlI" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2406227AbfJWXDv (ORCPT ); Wed, 23 Oct 2019 19:03:51 -0400 Received: from mail-pg1-f193.google.com ([209.85.215.193]:42492 "EHLO mail-pg1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1733196AbfJWXDv (ORCPT ); Wed, 23 Oct 2019 19:03:51 -0400 Received: by mail-pg1-f193.google.com with SMTP id f14so12992297pgi.9; Wed, 23 Oct 2019 16:03:50 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version; bh=/OHxiXD2KyXURICS7ZLFhn4YJcbAYHn2yp+8MzAvfDc=; b=spC33OlITWelnU7Z8JWyAbqDTQvQywvirjEaDIyHeT0QVWGLczOmCa5xCp0DVwywjR msJY8gY9kornpUrkl+cVGEcIBGhjTh/jxUT1E6d9A1L87mxVBMYrbgYD80Tzy/0u8nHY 3icB+hu4GJobS22XqmGng/Ewvrz+tRltrbQS4y015GxTjShJVbBxpboZZwxsLLsqYhwM YTxtbgYWBE7OuslRYPmPkbcYIiWHZPANhBMbw3je3CWJH18AvwZJAlNBnMsarje6COYw Zo/n9cWmYRPom3E3jeZmTUBKk0u2UGzNuXKNaUJNwrYYfZdEizz9qzui1uv0RMo9lrts O30A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version; bh=/OHxiXD2KyXURICS7ZLFhn4YJcbAYHn2yp+8MzAvfDc=; b=JKNGeEUv+W7wlRPXfh4366uwwbwxULcgbneH5E0CEUi4AKAXQHW8VH4R7+/9i0aIv6 Y35ap/WcmxK6uJKXzCRthMVJxfa0NL9tgbOCxJ/Sks4BDY6Vj+0a4IaVJaA1f32YXSs4 fvkWqb0G//Cxw/CaKSBARdGOeTT/nmYXDMS6/gjbz+lr4KQbqFp47OMBr0E10qNNnzxy 5EbeThKuZFa2tWLuwIP7CnmmMZDywLOD7bpP/d9ZscQ+YKCdx9vnyJtssCn0VvgvJ9oG 36izUo7u1eK2LJ2UnLBHkFFZ5Vdry3rGV+f5WftFLJnbbxl7hUMY24wbEizg5Fy7N9Ue 5qvw== X-Gm-Message-State: APjAAAXwr2N7MBiqKu92zG+AzNPHwi0uA0LtgiH23TJNcfy0lHi373BB QqtdzwxcUvo1p6X0Uqr9CzE= X-Google-Smtp-Source: APXvYqy7Jps/4WrxQ+4F846S7kPT3OEJ2c0PSYVG+Y1beL2fC2dtGNo/1v5tyXd/G8GbepPoYvyWKA== X-Received: by 2002:a63:2326:: with SMTP id j38mr12500963pgj.283.1571871830405; Wed, 23 Oct 2019 16:03:50 -0700 (PDT) Received: from [172.26.117.3] ([2620:10d:c090:180::cbd8]) by smtp.gmail.com with ESMTPSA id w2sm19272129pgm.18.2019.10.23.16.03.48 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 23 Oct 2019 16:03:49 -0700 (PDT) From: "Jonathan Lemon" To: "Magnus Karlsson" Cc: bjorn.topel@intel.com, ast@kernel.org, daniel@iogearbox.net, netdev@vger.kernel.org, kal.conley@dectris.com, bpf@vger.kernel.org Subject: Re: [PATCH bpf] xsk: fix registration of Rx-only sockets Date: Wed, 23 Oct 2019 16:03:48 -0700 X-Mailer: MailMate (1.13r5655) Message-ID: In-Reply-To: <1571645818-16244-1-git-send-email-magnus.karlsson@intel.com> References: <1571645818-16244-1-git-send-email-magnus.karlsson@intel.com> MIME-Version: 1.0 Content-Type: text/plain Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org On 21 Oct 2019, at 1:16, Magnus Karlsson wrote: > 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. A future improvement might be renaming umem->xsk_list to umem->xsk_tx_list or similar, in order to make it clear that the list is only used on the TX path. > > Fixes: ac98d8aab61b ("xsk: wire upp Tx zero-copy functions") > Reported-by: Kal Cutter Conley > Signed-off-by: Magnus Karlsson Acked-by: Jonathan Lemon -- Jonathan