From mboxrd@z Thu Jan 1 00:00:00 1970 From: Roi Dayan Subject: Re: [Patch net-next] net_sched: move the empty tp check from ->destroy() to ->delete() Date: Thu, 24 Nov 2016 13:01:18 +0200 Message-ID: <5836C87E.8050506@mellanox.com> References: <1479952708-26763-1-git-send-email-xiyou.wangcong@gmail.com> <5836A4D4.2010500@mellanox.com> <5836BD82.6080407@iogearbox.net> Mime-Version: 1.0 Content-Type: text/plain; charset="windows-1252"; format=flowed Content-Transfer-Encoding: 7bit Cc: , , John Fastabend To: Daniel Borkmann , Cong Wang , Return-path: Received: from mail-db5eur01on0067.outbound.protection.outlook.com ([104.47.2.67]:5488 "EHLO EUR01-DB5-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S938647AbcKXMfD (ORCPT ); Thu, 24 Nov 2016 07:35:03 -0500 In-Reply-To: <5836BD82.6080407@iogearbox.net> Sender: netdev-owner@vger.kernel.org List-ID: On 24/11/2016 12:14, Daniel Borkmann wrote: > On 11/24/2016 09:29 AM, Roi Dayan wrote: >> Hi, >> >> I'm testing this patch with KASAN enabled and got into a new kernel >> crash I didn't hit before. >> >> [ 1860.725065] >> ================================================================== >> [ 1860.733893] BUG: KASAN: use-after-free in >> __netif_receive_skb_core+0x1ebe/0x29a0 at addr ffff880a68b04028 >> [ 1860.745415] Read of size 8 by task CPU 0/KVM/5334 >> [ 1860.751368] CPU: 8 PID: 5334 Comm: CPU 0/KVM Tainted: G O >> 4.9.0-rc3+ #18 >> [ 1860.760547] Hardware name: HP ProLiant DL380p Gen8, BIOS P70 >> 07/01/2015 >> [ 1860.768036] Call Trace: >> [ 1860.771307] [] dump_stack+0x63/0x81 >> [ 1860.777167] [] kasan_object_err+0x21/0x70 >> [ 1860.783826] [] kasan_report_error+0x1ed/0x4e0 >> [ 1860.790640] [] ? csum_partial+0x11/0x20 >> [ 1860.796871] [] ? csum_partial_ext+0x9/0x10 >> [ 1860.803571] [] ? __skb_checksum+0x115/0x8d0 >> [ 1860.810370] [] >> __asan_report_load8_noabort+0x61/0x70 >> [ 1860.818263] [] ? >> __netif_receive_skb_core+0x1ebe/0x29a0 >> [ 1860.826215] [] >> __netif_receive_skb_core+0x1ebe/0x29a0 >> [ 1860.833991] [] ? netdev_info+0x100/0x100 >> [ 1860.840529] [] ? udp4_gro_receive+0x802/0x1090 >> [ 1860.847783] [] ? find_next_bit+0x18/0x20 >> [ 1860.854126] [] __netif_receive_skb+0x24/0x150 >> [ 1860.861695] [] >> netif_receive_skb_internal+0xa1/0x1d0 >> [ 1860.869366] [] ? __netif_receive_skb+0x150/0x150 >> [ 1860.876464] [] ? dev_gro_receive+0x969/0x1660 >> [ 1860.883924] [] napi_gro_receive+0x1df/0x300 >> [ 1860.890744] [] >> mlx5e_handle_rx_cqe_rep+0x83d/0xd30 [mlx5_core] >> >> checking with gdb >> >> (gdb) l *(__netif_receive_skb_core+0x1ebe) >> 0xffffffff8249c3fe is in __netif_receive_skb_core (net/core/dev.c:3937). >> 3932 *pt_prev = NULL; >> 3933 } >> 3934 >> 3935 qdisc_skb_cb(skb)->pkt_len = skb->len; >> 3936 skb->tc_verd = SET_TC_AT(skb->tc_verd, AT_INGRESS); >> 3937 qdisc_bstats_cpu_update(cl->q, skb); >> 3938 >> 3939 switch (tc_classify(skb, cl, &cl_res, false)) { >> 3940 case TC_ACT_OK: >> 3941 case TC_ACT_RECLASSIFY: > > Can you elaborate some more on your test-case? Adding/dropping ingress > qdisc with > some classifier on it in a loop while traffic goes through? I first delete the qdisc ingress from the relevant interface I start traffic on it then I add the qdisc ingress to the relevant interface and start adding tc flower rules to match the traffic. > > Thanks, > Daniel