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=-15.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 76AB6C432BE for ; Tue, 17 Aug 2021 11:25:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5457660FC3 for ; Tue, 17 Aug 2021 11:25:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236713AbhHQL0M (ORCPT ); Tue, 17 Aug 2021 07:26:12 -0400 Received: from mga07.intel.com ([134.134.136.100]:22522 "EHLO mga07.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231515AbhHQL0L (ORCPT ); Tue, 17 Aug 2021 07:26:11 -0400 X-IronPort-AV: E=McAfee;i="6200,9189,10078"; a="279788857" X-IronPort-AV: E=Sophos;i="5.84,328,1620716400"; d="scan'208";a="279788857" Received: from fmsmga007.fm.intel.com ([10.253.24.52]) by orsmga105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 17 Aug 2021 04:25:38 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.84,328,1620716400"; d="scan'208";a="449226687" Received: from ranger.igk.intel.com ([10.102.21.164]) by fmsmga007.fm.intel.com with ESMTP; 17 Aug 2021 04:25:31 -0700 Date: Tue, 17 Aug 2021 13:10:47 +0200 From: Maciej Fijalkowski To: Feng zhou Cc: jesse.brandeburg@intel.com, anthony.l.nguyen@intel.com, davem@davemloft.net, kuba@kernel.org, ast@kernel.org, daniel@iogearbox.net, hawk@kernel.org, john.fastabend@gmail.com, jeffrey.t.kirsher@intel.com, magnus.karlsson@intel.com, intel-wired-lan@lists.osuosl.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, bpf@vger.kernel.org, duanxiongchun@bytedance.com, songmuchun@bytedance.com, zhouchengming@bytedance.com, chenying.kernel@bytedance.com, zhengqi.arch@bytedance.com, wangdongdong.6@bytedance.com Subject: Re: [PATCH] ixgbe: Fix NULL pointer dereference in ixgbe_xdp_setup Message-ID: <20210817111047.GA8143@ranger.igk.intel.com> References: <20210817075407.11961-1-zhoufeng.zf@bytedance.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210817075407.11961-1-zhoufeng.zf@bytedance.com> User-Agent: Mutt/1.12.1 (2019-06-15) Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Tue, Aug 17, 2021 at 03:54:07PM +0800, Feng zhou wrote: > From: Feng Zhou > > The ixgbe driver currently generates a NULL pointer dereference with > some machine (online cpus < 63). This is due to the fact that the > maximum value of num_xdp_queues is nr_cpu_ids. Code is in > "ixgbe_set_rss_queues"". That's a good catch, but we should fix set channels callback so that it will not allow a setting of queues to be higher than the num_online_cpus(). Please also include the tree in the patch subject that you're directing the patch to. I'd be also thankful if you Cc me on Intel XDP related patches. Thanks! > > Here's how the problem repeats itself: > Some machine (online cpus < 63), And user set num_queues to 63 through > ethtool. Code is in the "ixgbe_set_channels", > adapter->ring_feature[RING_F_FDIR].limit = count; > It becames 63. > When user use xdp, "ixgbe_set_rss_queues" will set queues num. > adapter->num_rx_queues = rss_i; > adapter->num_tx_queues = rss_i; > adapter->num_xdp_queues = ixgbe_xdp_queues(adapter); > And rss_i's value is from > f = &adapter->ring_feature[RING_F_FDIR]; > rss_i = f->indices = f->limit; > So "num_rx_queues" > "num_xdp_queues", when run to "ixgbe_xdp_setup", > for (i = 0; i < adapter->num_rx_queues; i++) > if (adapter->xdp_ring[i]->xsk_umem) > lead to panic. > Call trace: > [exception RIP: ixgbe_xdp+368] > RIP: ffffffffc02a76a0 RSP: ffff9fe16202f8d0 RFLAGS: 00010297 > RAX: 0000000000000000 RBX: 0000000000000020 RCX: 0000000000000000 > RDX: 0000000000000000 RSI: 000000000000001c RDI: ffffffffa94ead90 > RBP: ffff92f8f24c0c18 R8: 0000000000000000 R9: 0000000000000000 > R10: ffff9fe16202f830 R11: 0000000000000000 R12: ffff92f8f24c0000 > R13: ffff9fe16202fc01 R14: 000000000000000a R15: ffffffffc02a7530 > ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018 > 7 [ffff9fe16202f8f0] dev_xdp_install at ffffffffa89fbbcc > 8 [ffff9fe16202f920] dev_change_xdp_fd at ffffffffa8a08808 > 9 [ffff9fe16202f960] do_setlink at ffffffffa8a20235 > 10 [ffff9fe16202fa88] rtnl_setlink at ffffffffa8a20384 > 11 [ffff9fe16202fc78] rtnetlink_rcv_msg at ffffffffa8a1a8dd > 12 [ffff9fe16202fcf0] netlink_rcv_skb at ffffffffa8a717eb > 13 [ffff9fe16202fd40] netlink_unicast at ffffffffa8a70f88 > 14 [ffff9fe16202fd80] netlink_sendmsg at ffffffffa8a71319 > 15 [ffff9fe16202fdf0] sock_sendmsg at ffffffffa89df290 > 16 [ffff9fe16202fe08] __sys_sendto at ffffffffa89e19c8 > 17 [ffff9fe16202ff30] __x64_sys_sendto at ffffffffa89e1a64 > 18 [ffff9fe16202ff38] do_syscall_64 at ffffffffa84042b9 > 19 [ffff9fe16202ff50] entry_SYSCALL_64_after_hwframe at ffffffffa8c0008c > > Fixes: 4a9b32f30f80 ("ixgbe: fix potential RX buffer starvation for > AF_XDP") > Signed-off-by: Feng Zhou > --- > drivers/net/ethernet/intel/ixgbe/ixgbe_main.c | 8 ++++++-- > 1 file changed, 6 insertions(+), 2 deletions(-) > > diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c > index 14aea40da50f..5db496cc5070 100644 > --- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c > +++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c > @@ -10112,6 +10112,7 @@ static int ixgbe_xdp_setup(struct net_device *dev, struct bpf_prog *prog) > struct ixgbe_adapter *adapter = netdev_priv(dev); > struct bpf_prog *old_prog; > bool need_reset; > + int num_queues; > > if (adapter->flags & IXGBE_FLAG_SRIOV_ENABLED) > return -EINVAL; > @@ -10161,11 +10162,14 @@ static int ixgbe_xdp_setup(struct net_device *dev, struct bpf_prog *prog) > /* Kick start the NAPI context if there is an AF_XDP socket open > * on that queue id. This so that receiving will start. > */ > - if (need_reset && prog) > - for (i = 0; i < adapter->num_rx_queues; i++) > + if (need_reset && prog) { > + num_queues = min_t(int, adapter->num_rx_queues, > + adapter->num_xdp_queues); > + for (i = 0; i < num_queues; i++) > if (adapter->xdp_ring[i]->xsk_pool) > (void)ixgbe_xsk_wakeup(adapter->netdev, i, > XDP_WAKEUP_RX); > + } > > return 0; > } > -- > 2.11.0 >