From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752555AbdLVLQS (ORCPT ); Fri, 22 Dec 2017 06:16:18 -0500 Received: from mx1.redhat.com ([209.132.183.28]:58682 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750786AbdLVLQN (ORCPT ); Fri, 22 Dec 2017 06:16:13 -0500 Date: Fri, 22 Dec 2017 09:16:02 -0200 From: Marcelo Ricardo Leitner To: Dmitry Vyukov Cc: David Ahern , syzbot , LKML , Ingo Molnar , Peter Zijlstra , syzkaller-bugs@googlegroups.com, David Miller , Florian Westphal , Daniel Borkmann , Xin Long , jakub.kicinski@netronome.com, mschiffer@universe-factory.net, Vladislav Yasevich , Jiri Benc , netdev , Neil Horman , linux-sctp@vger.kernel.org Subject: Re: INFO: task hung in bpf_exit_net Message-ID: <20171222111602.GB32765@localhost.localdomain> References: <001a1143fd00a8cc790560b0b552@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.9.1 (2017-09-22) X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.27]); Fri, 22 Dec 2017 11:16:13 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Dec 22, 2017 at 11:58:08AM +0100, Dmitry Vyukov wrote: > On Tue, Dec 19, 2017 at 7:20 PM, David Ahern wrote: > > On 12/19/17 5:47 AM, Dmitry Vyukov wrote: > >> On Tue, Dec 19, 2017 at 1:36 PM, syzbot > >> > >> wrote: > >>> Hello, > >>> > >>> syzkaller hit the following crash on > >>> 7ceb97a071e80f1b5e4cd5a36de135612a836388 > >>> git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/master > >>> compiler: gcc (GCC) 7.1.1 20170620 > >>> .config is attached > >>> Raw console output is attached. > >>> > >>> Unfortunately, I don't have any reproducer for this bug yet. > >>> > >>> > >>> sctp: sctp_transport_update_pmtu: Reported pmtu 508 too low, using default > >>> minimum of 512 > >>> INFO: task kworker/u4:0:5 blocked for more than 120 seconds. > >>> Not tainted 4.15.0-rc2-next-20171205+ #59 > >>> "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. > >>> kworker/u4:0 D15808 5 2 0x80000000 > >>> Workqueue: netns cleanup_net > >>> Call Trace: > >>> context_switch kernel/sched/core.c:2800 [inline] > >>> __schedule+0x8eb/0x2060 kernel/sched/core.c:3376 > >>> schedule+0xf5/0x430 kernel/sched/core.c:3435 > >>> schedule_preempt_disabled+0x10/0x20 kernel/sched/core.c:3493 > >>> __mutex_lock_common kernel/locking/mutex.c:833 [inline] > >>> __mutex_lock+0xaad/0x1a80 kernel/locking/mutex.c:893 > >>> mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908 > >>> rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74 > >>> tc_action_net_exit include/net/act_api.h:125 [inline] > >>> bpf_exit_net+0x1a2/0x340 net/sched/act_bpf.c:408 > >>> ops_exit_list.isra.6+0xae/0x150 net/core/net_namespace.c:142 > >>> cleanup_net+0x5c7/0xb60 net/core/net_namespace.c:484 > >>> process_one_work+0xbfd/0x1bc0 kernel/workqueue.c:2113 > >>> worker_thread+0x223/0x1990 kernel/workqueue.c:2247 > >>> kthread+0x37a/0x440 kernel/kthread.c:238 > >>> ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:517 > >>> > >>> Showing all locks held in the system: > >>> 4 locks held by kworker/u4:0/5: > >>> #0: ((wq_completion)"%s""netns"){+.+.}, at: [<00000000b9f061a2>] > >>> __write_once_size include/linux/compiler.h:212 [inline] > >>> #0: ((wq_completion)"%s""netns"){+.+.}, at: [<00000000b9f061a2>] > >>> atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] > >>> #0: ((wq_completion)"%s""netns"){+.+.}, at: [<00000000b9f061a2>] > >>> atomic_long_set include/asm-generic/atomic-long.h:57 [inline] > >>> #0: ((wq_completion)"%s""netns"){+.+.}, at: [<00000000b9f061a2>] > >>> set_work_data kernel/workqueue.c:619 [inline] > >>> #0: ((wq_completion)"%s""netns"){+.+.}, at: [<00000000b9f061a2>] > >>> set_work_pool_and_clear_pending kernel/workqueue.c:646 [inline] > >>> #0: ((wq_completion)"%s""netns"){+.+.}, at: [<00000000b9f061a2>] > >>> process_one_work+0xad4/0x1bc0 kernel/workqueue.c:2084 > >>> #1: (net_cleanup_work){+.+.}, at: [<000000006c7c48a3>] > >>> process_one_work+0xb2f/0x1bc0 kernel/workqueue.c:2088 > >>> #2: (net_mutex){+.+.}, at: [<00000000bf4709f3>] cleanup_net+0x247/0xb60 > >>> net/core/net_namespace.c:450 > >>> #3: (rtnl_mutex){+.+.}, at: [<0000000053390f0b>] rtnl_lock+0x17/0x20 > >>> net/core/rtnetlink.c:74 > >>> 3 locks held by kworker/1:0/17: > >>> #0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: [<00000000b9f061a2>] > >>> __write_once_size include/linux/compiler.h:212 [inline] > >>> #0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: [<00000000b9f061a2>] > >>> atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] > >>> #0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: [<00000000b9f061a2>] > >>> atomic_long_set include/asm-generic/atomic-long.h:57 [inline] > >>> #0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: [<00000000b9f061a2>] > >>> set_work_data kernel/workqueue.c:619 [inline] > >>> #0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: [<00000000b9f061a2>] > >>> set_work_pool_and_clear_pending kernel/workqueue.c:646 [inline] > >>> #0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: [<00000000b9f061a2>] > >>> process_one_work+0xad4/0x1bc0 kernel/workqueue.c:2084 > >>> #1: ((addr_chk_work).work){+.+.}, at: [<000000006c7c48a3>] > >>> process_one_work+0xb2f/0x1bc0 kernel/workqueue.c:2088 > >>> #2: (rtnl_mutex){+.+.}, at: [<0000000053390f0b>] rtnl_lock+0x17/0x20 > >>> net/core/rtnetlink.c:74 > >>> 2 locks held by khungtaskd/675: > >>> #0: (rcu_read_lock){....}, at: [<00000000587c8471>] > >>> check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline] > >>> #0: (rcu_read_lock){....}, at: [<00000000587c8471>] watchdog+0x1c5/0xd60 > >>> kernel/hung_task.c:249 > >>> #1: (tasklist_lock){.+.+}, at: [<000000005288685e>] > >>> debug_show_all_locks+0xd3/0x400 kernel/locking/lockdep.c:4554 > >>> 1 lock held by rsyslogd/2974: > >>> #0: (&f->f_pos_lock){+.+.}, at: [<0000000011e00499>] > >>> __fdget_pos+0x131/0x1a0 fs/file.c:770 > >>> 2 locks held by getty/3056: > >>> #0: (&tty->ldisc_sem){++++}, at: [<00000000b9fd70a9>] > >>> ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 > >>> #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000abb3bd08>] > >>> n_tty_read+0x2f2/0x1a10 drivers/tty/n_tty.c:2131 > >>> 2 locks held by getty/3057: > >>> #0: (&tty->ldisc_sem){++++}, at: [<00000000b9fd70a9>] > >>> ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 > >>> #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000abb3bd08>] > >>> n_tty_read+0x2f2/0x1a10 drivers/tty/n_tty.c:2131 > >>> 2 locks held by getty/3058: > >>> #0: (&tty->ldisc_sem){++++}, at: [<00000000b9fd70a9>] > >>> ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 > >>> #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000abb3bd08>] > >>> n_tty_read+0x2f2/0x1a10 drivers/tty/n_tty.c:2131 > >>> 2 locks held by getty/3059: > >>> #0: (&tty->ldisc_sem){++++}, at: [<00000000b9fd70a9>] > >>> ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 > >>> #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000abb3bd08>] > >>> n_tty_read+0x2f2/0x1a10 drivers/tty/n_tty.c:2131 > >>> 2 locks held by getty/3060: > >>> #0: (&tty->ldisc_sem){++++}, at: [<00000000b9fd70a9>] > >>> ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 > >>> #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000abb3bd08>] > >>> n_tty_read+0x2f2/0x1a10 drivers/tty/n_tty.c:2131 > >>> 2 locks held by getty/3061: > >>> #0: (&tty->ldisc_sem){++++}, at: [<00000000b9fd70a9>] > >>> ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 > >>> #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000abb3bd08>] > >>> n_tty_read+0x2f2/0x1a10 drivers/tty/n_tty.c:2131 > >>> 2 locks held by getty/3062: > >>> #0: (&tty->ldisc_sem){++++}, at: [<00000000b9fd70a9>] > >>> ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 > >>> #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000abb3bd08>] > >>> n_tty_read+0x2f2/0x1a10 drivers/tty/n_tty.c:2131 > >>> > >>> ============================================= > >>> > >>> NMI backtrace for cpu 0 > >>> CPU: 0 PID: 675 Comm: khungtaskd Not tainted 4.15.0-rc2-next-20171205+ #59 > >>> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS > >>> Google 01/01/2011 > >>> Call Trace: > >>> __dump_stack lib/dump_stack.c:17 [inline] > >>> dump_stack+0x194/0x257 lib/dump_stack.c:53 > >>> nmi_cpu_backtrace+0x1d2/0x210 lib/nmi_backtrace.c:103 > >>> nmi_trigger_cpumask_backtrace+0x122/0x180 lib/nmi_backtrace.c:62 > >>> arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38 > >>> trigger_all_cpu_backtrace include/linux/nmi.h:138 [inline] > >>> check_hung_task kernel/hung_task.c:132 [inline] > >>> check_hung_uninterruptible_tasks kernel/hung_task.c:190 [inline] > >>> watchdog+0x90c/0xd60 kernel/hung_task.c:249 > >>> kthread+0x37a/0x440 kernel/kthread.c:238 > >>> ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:517 > >>> Sending NMI from CPU 0 to CPUs 1: > >>> NMI backtrace for cpu 1 > >>> CPU: 1 PID: 13156 Comm: syz-executor7 Not tainted 4.15.0-rc2-next-20171205+ > >>> #59 > >>> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS > >>> Google 01/01/2011 > >>> task: 000000005209c120 task.stack: 00000000ffaab0e8 > >>> RIP: 0010:inb arch/x86/include/asm/io.h:348 [inline] > >>> RIP: 0010:io_serial_in+0x6b/0x90 drivers/tty/serial/8250/8250_port.c:434 > >>> RSP: 0018:ffff8801c0a16e70 EFLAGS: 00000002 > >>> RAX: dffffc0000000000 RBX: 00000000000003fd RCX: 0000000000000000 > >>> RDX: 00000000000003fd RSI: ffffc90003745000 RDI: ffffffff87cf1a40 > >>> RBP: ffff8801c0a16e80 R08: 0000000000000005 R09: 000000000000000c > >>> R10: 0000000000000000 R11: ffffffff8748dd20 R12: ffffffff87cf1a00 > >>> R13: 0000000000000020 R14: fffffbfff0f9e387 R15: fffffbfff0f9e34a > >>> FS: 00007f6d52e3f700(0000) GS:ffff8801db500000(0000) knlGS:0000000000000000 > >>> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > >>> CR2: 000000c42005de80 CR3: 00000001c368a000 CR4: 00000000001406e0 > >>> DR0: 0000000020000000 DR1: 0000000000000000 DR2: 0000000000000000 > >>> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 > >>> Call Trace: > >>> serial_in drivers/tty/serial/8250/8250.h:111 [inline] > >>> wait_for_xmitr+0x93/0x1e0 drivers/tty/serial/8250/8250_port.c:2033 > >>> serial8250_console_putchar+0x1f/0x60 > >>> drivers/tty/serial/8250/8250_port.c:3170 > >>> uart_console_write+0xac/0xe0 drivers/tty/serial/serial_core.c:1858 > >>> serial8250_console_write+0x647/0xa20 > >>> drivers/tty/serial/8250/8250_port.c:3236 > >>> univ8250_console_write+0x5f/0x70 drivers/tty/serial/8250/8250_core.c:590 > >>> call_console_drivers kernel/printk/printk.c:1574 [inline] > >>> console_unlock+0x788/0xd70 kernel/printk/printk.c:2233 > >>> vprintk_emit+0x4ad/0x590 kernel/printk/printk.c:1757 > >>> vprintk_default+0x28/0x30 kernel/printk/printk.c:1796 > >>> vprintk_func+0x57/0xc0 kernel/printk/printk_safe.c:379 > >>> printk+0xaa/0xca kernel/printk/printk.c:1829 > >>> nla_parse+0x374/0x3d0 lib/nlattr.c:257 > >>> nlmsg_parse include/net/netlink.h:398 [inline] > >>> nl80211_dump_wiphy_parse.isra.37.constprop.83+0x138/0x5c0 > >>> net/wireless/nl80211.c:1920 > >>> nl80211_dump_interface+0x596/0x820 net/wireless/nl80211.c:2660 > >>> genl_lock_dumpit+0x68/0x90 net/netlink/genetlink.c:480 > >>> netlink_dump+0x48c/0xce0 net/netlink/af_netlink.c:2186 > >>> __netlink_dump_start+0x4f0/0x6d0 net/netlink/af_netlink.c:2283 > >>> genl_family_rcv_msg+0xd27/0xfc0 net/netlink/genetlink.c:548 > >>> genl_rcv_msg+0xb2/0x140 net/netlink/genetlink.c:624 > >>> netlink_rcv_skb+0x216/0x440 net/netlink/af_netlink.c:2405 > >>> genl_rcv+0x28/0x40 net/netlink/genetlink.c:635 > >>> netlink_unicast_kernel net/netlink/af_netlink.c:1272 [inline] > >>> netlink_unicast+0x4e8/0x6f0 net/netlink/af_netlink.c:1298 > >>> netlink_sendmsg+0xa4a/0xe70 net/netlink/af_netlink.c:1861 > >>> sock_sendmsg_nosec net/socket.c:636 [inline] > >>> sock_sendmsg+0xca/0x110 net/socket.c:646 > >>> sock_write_iter+0x320/0x5e0 net/socket.c:915 > >>> call_write_iter include/linux/fs.h:1776 [inline] > >>> new_sync_write fs/read_write.c:469 [inline] > >>> __vfs_write+0x68a/0x970 fs/read_write.c:482 > >>> vfs_write+0x18f/0x510 fs/read_write.c:544 > >>> SYSC_write fs/read_write.c:589 [inline] > >>> SyS_write+0xef/0x220 fs/read_write.c:581 > >>> entry_SYSCALL_64_fastpath+0x1f/0x96 > >>> RIP: 0033:0x4529d9 > >>> RSP: 002b:00007f6d52e3ec58 EFLAGS: 00000212 ORIG_RAX: 0000000000000001 > >>> RAX: ffffffffffffffda RBX: 00007f6d52e3f700 RCX: 00000000004529d9 > >>> RDX: 0000000000000024 RSI: 0000000020454000 RDI: 0000000000000016 > >>> RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 > >>> R10: 0000000000000000 R11: 0000000000000212 R12: 0000000000000000 > >>> R13: 0000000000a6f7ff R14: 00007f6d52e3f9c0 R15: 0000000000000000 > >>> Code: 24 d9 00 00 00 49 8d 7c 24 40 48 b8 00 00 00 00 00 fc ff df 48 89 fa > >>> 48 c1 ea 03 d3 e3 80 3c 02 00 75 17 41 03 5c 24 40 89 da ec <5b> 0f b6 c0 41 > >>> 5c 5d c3 e8 38 b0 18 ff eb c2 e8 91 b0 18 ff eb > >>> > >>> > >>> --- > >>> This bug is generated by a dumb bot. It may contain errors. > >>> See https://goo.gl/tpsmEJ for details. > >>> Direct all questions to syzkaller@googlegroups.com. > >>> Please credit me with: Reported-by: syzbot > >>> > >>> syzbot will keep track of this bug report. > >>> Once a fix for this bug is merged into any tree, reply to this email with: > >>> #syz fix: exact-commit-title > >>> To mark this as a duplicate of another syzbot report, please reply with: > >>> #syz dup: exact-subject-of-another-report > >>> If it's a one-off invalid bug report, please reply with: > >>> #syz invalid > >>> Note: if the crash happens again, it will cause creation of a new bug > >>> report. > >>> Note: all commands must start from beginning of the line in the email body. > >>> > >>> -- > >>> You received this message because you are subscribed to the Google Groups > >>> "syzkaller-bugs" group. > >>> To unsubscribe from this group and stop receiving emails from it, send an > >>> email to syzkaller-bugs+unsubscribe@googlegroups.com. > >>> To view this discussion on the web visit > >>> https://groups.google.com/d/msgid/syzkaller-bugs/001a1143fd00a8cc790560b0b552%40google.com. > >>> For more options, visit https://groups.google.com/d/optout. > >> > >> > >> This looks like +rtnetlink issue. > >> > > > > Same with this one, perhaps related to / fixed by: > > http://patchwork.ozlabs.org/patch/850957/ > > > > > > Looking at the log, this one seems to be an infinite loop in SCTP code > with console output in it. Kernel is busy printing gazilion of: Do you have a link for such log? I don't seem to have received the initial syzbot email, so I don't have its attachments. Or if you may, please fwd it to me/list. Thanks. > > [ 176.491099] sctp: sctp_transport_update_pmtu: Reported pmtu 508 too > low, using default minimum of 512 > ** 110 printk messages dropped ** > [ 176.503409] sctp: sctp_transport_update_pmtu: Reported pmtu 508 too > low, using default minimum of 512 > ** 103 printk messages dropped ** > ... > [ 246.742374] sctp: sctp_transport_update_pmtu: Reported pmtu 508 too > low, using default minimum of 512 > [ 246.742484] sctp: sctp_transport_update_pmtu: Reported pmtu 508 too > low, using default minimum of 512 > [ 246.742590] sctp: sctp_transport_update_pmtu: Reported pmtu 508 too > low, using default minimum of 512 > > Looks like a different issue. >