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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B2B82C433EF for ; Mon, 4 Oct 2021 20:54:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 88F0861360 for ; Mon, 4 Oct 2021 20:54:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235404AbhJDU4f (ORCPT ); Mon, 4 Oct 2021 16:56:35 -0400 Received: from mga05.intel.com ([192.55.52.43]:30197 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232496AbhJDU4c (ORCPT ); Mon, 4 Oct 2021 16:56:32 -0400 X-IronPort-AV: E=McAfee;i="6200,9189,10127"; a="311797383" X-IronPort-AV: E=Sophos;i="5.85,346,1624345200"; d="scan'208";a="311797383" Received: from fmsmga006.fm.intel.com ([10.253.24.20]) by fmsmga105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 04 Oct 2021 13:54:38 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.85,346,1624345200"; d="scan'208";a="711581783" Received: from vcostago-desk1.jf.intel.com (HELO vcostago-desk1) ([10.54.70.10]) by fmsmga006.fm.intel.com with ESMTP; 04 Oct 2021 13:54:38 -0700 From: Vinicius Costa Gomes To: Eric Dumazet , "David S . Miller" , Jakub Kicinski Cc: netdev , Eric Dumazet , Eric Dumazet , Davide Caratti , syzbot Subject: Re: [PATCH net] net/sched: sch_taprio: properly cancel timer from taprio_destroy() In-Reply-To: <20211004195522.2041705-1-eric.dumazet@gmail.com> References: <20211004195522.2041705-1-eric.dumazet@gmail.com> Date: Mon, 04 Oct 2021 13:55:11 -0700 Message-ID: <875yuc33yo.fsf@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Eric Dumazet writes: > From: Eric Dumazet > > There is a comment in qdisc_create() about us not calling ops->reset() > in some cases. > > err_out4: > /* > * Any broken qdiscs that would require a ops->reset() here? > * The qdisc was never in action so it shouldn't be necessary. > */ > > As taprio sets a timer before actually receiving a packet, we need > to cancel it from ops->destroy, just in case ops->reset has not > been called. > > syzbot reported: > > ODEBUG: free active (active state 0) object type: hrtimer hint: advance_sched+0x0/0x9a0 arch/x86/include/asm/atomic64_64.h:22 > WARNING: CPU: 0 PID: 8441 at lib/debugobjects.c:505 debug_print_object+0x16e/0x250 lib/debugobjects.c:505 > Modules linked in: > CPU: 0 PID: 8441 Comm: syz-executor813 Not tainted 5.14.0-rc6-syzkaller #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 > RIP: 0010:debug_print_object+0x16e/0x250 lib/debugobjects.c:505 > Code: ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 af 00 00 00 48 8b 14 dd e0 d3 e3 89 4c 89 ee 48 c7 c7 e0 c7 e3 89 e8 5b 86 11 05 <0f> 0b 83 05 85 03 92 09 01 48 83 c4 18 5b 5d 41 5c 41 5d 41 5e c3 > RSP: 0018:ffffc9000130f330 EFLAGS: 00010282 > RAX: 0000000000000000 RBX: 0000000000000003 RCX: 0000000000000000 > RDX: ffff88802baeb880 RSI: ffffffff815d87b5 RDI: fffff52000261e58 > RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000 > R10: ffffffff815d25ee R11: 0000000000000000 R12: ffffffff898dd020 > R13: ffffffff89e3ce20 R14: ffffffff81653630 R15: dffffc0000000000 > FS: 0000000000f0d300(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 00007ffb64b3e000 CR3: 0000000036557000 CR4: 00000000001506e0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > Call Trace: > __debug_check_no_obj_freed lib/debugobjects.c:987 [inline] > debug_check_no_obj_freed+0x301/0x420 lib/debugobjects.c:1018 > slab_free_hook mm/slub.c:1603 [inline] > slab_free_freelist_hook+0x171/0x240 mm/slub.c:1653 > slab_free mm/slub.c:3213 [inline] > kfree+0xe4/0x540 mm/slub.c:4267 > qdisc_create+0xbcf/0x1320 net/sched/sch_api.c:1299 > tc_modify_qdisc+0x4c8/0x1a60 net/sched/sch_api.c:1663 > rtnetlink_rcv_msg+0x413/0xb80 net/core/rtnetlink.c:5571 > netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2504 > netlink_unicast_kernel net/netlink/af_netlink.c:1314 [inline] > netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1340 > netlink_sendmsg+0x86d/0xdb0 net/netlink/af_netlink.c:1929 > sock_sendmsg_nosec net/socket.c:704 [inline] > sock_sendmsg+0xcf/0x120 net/socket.c:724 > ____sys_sendmsg+0x6e8/0x810 net/socket.c:2403 > ___sys_sendmsg+0xf3/0x170 net/socket.c:2457 > __sys_sendmsg+0xe5/0x1b0 net/socket.c:2486 > do_syscall_x64 arch/x86/entry/common.c:50 [inline] > do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 > > Fixes: 44d4775ca518 ("net/sched: sch_taprio: reset child qdiscs before freeing them") > Signed-off-by: Eric Dumazet > Cc: Davide Caratti > Reported-by: syzbot > --- Acked-by: Vinicius Costa Gomes -- Vinicius