batman_adv: batadv0: The MTU of interface batadv_slave_1 is too small (1500) to handle the transport of batman-adv packets. Packets going over this interface will be fragmented on layer2 which could impact the performance. Setting the MTU to 1560 would solve the problem. batman_adv: batadv0: Not using interface batadv_slave_1 (retrying later): interface not active IPv6: ADDRCONF(NETDEV_UP): bridge_slave_0: link is not ready IPv6: ADDRCONF(NETDEV_UP): bridge_slave_1: link is not ready INFO: task syz-executor.1:7999 blocked for more than 140 seconds. Not tainted 4.19.211-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.1 D28416 7999 6791 0x00000004 Call Trace: context_switch kernel/sched/core.c:2828 [inline] __schedule+0x887/0x2040 kernel/sched/core.c:3517 schedule+0x8d/0x1b0 kernel/sched/core.c:3561 schedule_timeout+0x92d/0xfe0 kernel/time/timer.c:1794 do_wait_for_common kernel/sched/completion.c:83 [inline] __wait_for_common kernel/sched/completion.c:104 [inline] wait_for_common+0x29c/0x470 kernel/sched/completion.c:115 __flush_work+0x4bb/0x8b0 kernel/workqueue.c:2926 __cancel_work_timer+0x412/0x590 kernel/workqueue.c:3013 p9_conn_destroy net/9p/trans_fd.c:904 [inline] p9_fd_close+0x305/0x520 net/9p/trans_fd.c:934 p9_client_create+0x901/0x12e0 net/9p/client.c:1084 v9fs_session_init+0x1dd/0x1770 fs/9p/v9fs.c:421 v9fs_mount+0x73/0x910 fs/9p/vfs_super.c:135 mount_fs+0xa3/0x310 fs/super.c:1261 vfs_kern_mount.part.0+0x68/0x470 fs/namespace.c:961 vfs_kern_mount fs/namespace.c:951 [inline] do_new_mount fs/namespace.c:2492 [inline] do_mount+0x115c/0x2f50 fs/namespace.c:2822 ksys_mount+0xcf/0x130 fs/namespace.c:3038 __do_sys_mount fs/namespace.c:3052 [inline] __se_sys_mount fs/namespace.c:3049 [inline] __x64_sys_mount+0xba/0x150 fs/namespace.c:3049 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7fe9ebadf5a9 Code: Bad RIP value. RSP: 002b:00007fe9ea010168 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007fe9ebc00120 RCX: 00007fe9ebadf5a9 RDX: 0000000020000100 RSI: 0000000020000080 RDI: 0000000000000000 RBP: 00007fe9ebb3a7b0 R08: 0000000020000180 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fff4e3263ef R14: 00007fe9ea010300 R15: 0000000000022000 device hsr_slave_0 entered promiscuous mode Showing all locks held in the system: device hsr_slave_1 entered promiscuous mode 3 locks held by kworker/u4:2/55: #0: 0000000095ef1e2d ((wq_completion)"%s""netns"){+.+.}, at: process_one_work+0x767/0x1570 kernel/workqueue.c:2124 #1: 000000006df9960d (net_cleanup_work){+.+.}, at: process_one_work+0x79c/0x1570 kernel/workqueue.c:2128 #2: 000000005b60c600 (pernet_ops_rwsem){++++}, at: cleanup_net+0xa8/0x8b0 net/core/net_namespace.c:521 1 lock held by khungtaskd/1570: #0: 000000008659abfc (rcu_read_lock){....}, at: debug_show_all_locks+0x53/0x265 kernel/locking/lockdep.c:4441 1 lock held by in:imklog/7801: #0: 000000001a65ce10 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x26f/0x310 fs/file.c:767 2 locks held by kworker/0:17/30668: #0: 000000007f4ae863 ((wq_completion)"rcu_gp"){+.+.}, at: process_one_work+0x767/0x1570 kernel/workqueue.c:2124 #1: 000000000c213fbe ((work_completion)(&rew.rew_work)){+.+.}, at: process_one_work+0x79c/0x1570 kernel/workqueue.c:2128 4 locks held by kworker/0:19/30672: #0: 00000000cc6ea614 ((wq_completion)"events"){+.+.}, at: process_one_work+0x767/0x1570 kernel/workqueue.c:2124 #1: 00000000589f39eb ((linkwatch_work).work){+.+.}, at: process_one_work+0x79c/0x1570 kernel/workqueue.c:2128 #2: 00000000d03a501c (rtnl_mutex){+.+.}, at: linkwatch_event+0xb/0x60 net/core/link_watch.c:236 #3: 000000003db3a2dd (rcu_preempt_state.exp_mutex){+.+.}, at: exp_funnel_lock kernel/rcu/tree_exp.h:297 [inline] #3: 000000003db3a2dd (rcu_preempt_state.exp_mutex){+.+.}, at: _synchronize_rcu_expedited+0x4dc/0x6f0 kernel/rcu/tree_exp.h:667 2 locks held by kworker/1:36/30776: #0: 00000000cc6ea614 ((wq_completion)"events"){+.+.}, at: process_one_work+0x767/0x1570 kernel/workqueue.c:2124 #1: 00000000f50e4a73 ((work_completion)(&m->wq)){+.+.}, at: process_one_work+0x79c/0x1570 kernel/workqueue.c:2128 1 lock held by syz-executor.0/14690: 1 lock held by syz-executor.4/14844: #0: 00000000d03a501c (rtnl_mutex){+.+.}, at: rtnl_lock net/core/rtnetlink.c:77 [inline] #0: 00000000d03a501c (rtnl_mutex){+.+.}, at: rtnetlink_rcv_msg+0x3fe/0xb80 net/core/rtnetlink.c:4779 ============================================= IPv6: ADDRCONF(NETDEV_UP): hsr_slave_0: link is not ready IPv6: ADDRCONF(NETDEV_UP): hsr_slave_1: link is not ready NMI backtrace for cpu 0 CPU: 0 PID: 1570 Comm: khungtaskd Not tainted 4.19.211-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/11/2022 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1fc/0x2ef lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x63/0xa2 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1a6/0x1f0 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:203 [inline] watchdog+0x991/0xe60 kernel/hung_task.c:287 kthread+0x33f/0x460 kernel/kthread.c:259 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 4685 Comm: systemd-journal Not tainted 4.19.211-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/11/2022 RIP: 0010:debug_lockdep_rcu_enabled kernel/rcu/update.c:253 [inline] RIP: 0010:debug_lockdep_rcu_enabled+0xae/0xe0 kernel/rcu/update.c:251 Code: fc ff df 48 89 fa 48 c1 ea 03 0f b6 14 02 48 89 f8 83 e0 07 83 c0 03 38 d0 7c 04 84 d2 75 32 8b 93 84 08 00 00 31 c0 5b 85 d2 <0f> 94 c0 c3 31 c0 5b c3 48 c7 c7 44 e0 26 8b e8 1e c3 47 00 e9 68 RSP: 0018:ffff8880a17b7900 EFLAGS: 00000002 RAX: 0000000000000000 RBX: ffff8880a17a83c0 RCX: 0000000000000001 RDX: 0000000000000001 RSI: 0000000000000002 RDI: ffff8880a17a8c44 RBP: ffffffff89f85fa0 R08: 0000000000000000 R09: ffffed101742455a R10: 0000000000000000 R11: ffffffff8c66505b R12: 1ffff110142f6f24 R13: ffffffff81453c79 R14: 0000000000000009 R15: ffff8880a17a83c0 FS: 00007f170c2ce8c0(0000) GS:ffff8880ba100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f17083d4000 CR3: 00000000a1128000 CR4: 00000000003406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: trace_lock_release include/trace/events/lock.h:58 [inline] lock_release+0x5c3/0x8b0 kernel/locking/lockdep.c:3926 rcu_lock_release include/linux/rcupdate.h:247 [inline] rcu_read_unlock include/linux/rcupdate.h:681 [inline] cgroup_account_cputime include/linux/cgroup.h:773 [inline] update_curr+0x3d6/0x870 kernel/sched/fair.c:858 dequeue_entity+0x1d/0x2800 kernel/sched/fair.c:4048 dequeue_task_fair+0x68/0x1b60 kernel/sched/fair.c:5241 __schedule+0x2d6/0x2040 kernel/sched/core.c:3467 schedule+0x8d/0x1b0 kernel/sched/core.c:3561 schedule_hrtimeout_range_clock+0x33e/0x390 kernel/time/hrtimer.c:2002 ep_poll+0xabb/0xcb0 fs/eventpoll.c:1817 do_epoll_wait+0x1aa/0x200 fs/eventpoll.c:2190 __do_sys_epoll_wait fs/eventpoll.c:2200 [inline] __se_sys_epoll_wait fs/eventpoll.c:2197 [inline] __x64_sys_epoll_wait+0x93/0xf0 fs/eventpoll.c:2197 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7f170b597303 Code: 49 89 ca b8 e8 00 00 00 0f 05 48 3d 01 f0 ff ff 73 34 c3 48 83 ec 08 e8 0b c2 00 00 48 89 04 24 49 89 ca b8 e8 00 00 00 0f 05 <48> 8b 3c 24 48 89 c2 e8 51 c2 00 00 48 89 d0 48 83 c4 08 48 3d 01 RSP: 002b:00007fff6f8af500 EFLAGS: 00000293 ORIG_RAX: 00000000000000e8 RAX: ffffffffffffffda RBX: 000055b2d17b71e0 RCX: 00007f170b597303 RDX: 0000000000000015 RSI: 00007fff6f8af510 RDI: 0000000000000008 RBP: 00007fff6f8af710 R08: 00007fff6f9f9000 R09: 000000b191d600cc R10: 00000000ffffffff R11: 0000000000000293 R12: 00007fff6f8af510 R13: 0000000000000001 R14: ffffffffffffffff R15: 0005ec822d4bdb2d