INFO: task kworker/u4:4:194 blocked for more than 143 seconds. Not tainted 5.11.0-rc2-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u4:4 state:D stack:25856 pid: 194 ppid: 2 flags:0x00004000 Workqueue: tc_filter_workqueue u32_delete_key_freepf_work Call Trace: context_switch kernel/sched/core.c:4313 [inline] __schedule+0x90c/0x21a0 kernel/sched/core.c:5064 schedule+0xcf/0x270 kernel/sched/core.c:5143 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:5202 __mutex_lock_common kernel/locking/mutex.c:1033 [inline] __mutex_lock+0x81a/0x1110 kernel/locking/mutex.c:1103 u32_delete_key_freepf_work+0xe/0x30 net/sched/cls_u32.c:439 process_one_work+0x98d/0x15f0 kernel/workqueue.c:2275 worker_thread+0x64c/0x1120 kernel/workqueue.c:2421 kthread+0x3b1/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296 INFO: task kworker/1:4:9740 blocked for more than 143 seconds. Not tainted 5.11.0-rc2-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/1:4 state:D stack:26192 pid: 9740 ppid: 2 flags:0x00004000 Workqueue: ipv6_addrconf addrconf_dad_work Call Trace: context_switch kernel/sched/core.c:4313 [inline] __schedule+0x90c/0x21a0 kernel/sched/core.c:5064 schedule+0xcf/0x270 kernel/sched/core.c:5143 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:5202 __mutex_lock_common kernel/locking/mutex.c:1033 [inline] __mutex_lock+0x81a/0x1110 kernel/locking/mutex.c:1103 addrconf_dad_work+0xa3/0x1280 net/ipv6/addrconf.c:4028 process_one_work+0x98d/0x15f0 kernel/workqueue.c:2275 worker_thread+0x64c/0x1120 kernel/workqueue.c:2421 kthread+0x3b1/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296 Showing all locks held in the system: 3 locks held by kworker/u4:2/88: 3 locks held by kworker/u4:4/194: #0: ffff88801514a938 ((wq_completion)tc_filter_workqueue){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff88801514a938 ((wq_completion)tc_filter_workqueue){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline] #0: ffff88801514a938 ((wq_completion)tc_filter_workqueue){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline] #0: ffff88801514a938 ((wq_completion)tc_filter_workqueue){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:616 [inline] #0: ffff88801514a938 ((wq_completion)tc_filter_workqueue){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:643 [inline] #0: ffff88801514a938 ((wq_completion)tc_filter_workqueue){+.+.}-{0:0}, at: process_one_work+0x871/0x15f0 kernel/workqueue.c:2246 #1: ffffc9000173fda8 ((work_completion)(&(rwork)->work)){+.+.}-{0:0}, at: process_one_work+0x8a5/0x15f0 kernel/workqueue.c:2250 #2: ffffffff8c946668 (rtnl_mutex){+.+.}-{3:3}, at: u32_delete_key_freepf_work+0xe/0x30 net/sched/cls_u32.c:439 1 lock held by khungtaskd/1660: #0: ffffffff8b363860 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6254 1 lock held by in:imklog/8170: #0: ffff88802345d4f0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:947 3 locks held by kworker/1:4/9740: #0: ffff8881470f8d38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff8881470f8d38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline] #0: ffff8881470f8d38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline] #0: ffff8881470f8d38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:616 [inline] #0: ffff8881470f8d38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:643 [inline] #0: ffff8881470f8d38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x871/0x15f0 kernel/workqueue.c:2246 #1: ffffc90015f7fda8 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x8a5/0x15f0 kernel/workqueue.c:2250 #2: ffffffff8c946668 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xa3/0x1280 net/ipv6/addrconf.c:4028 2 locks held by syz-executor.1/10000: 1 lock held by syz-executor.4/10020: #0: ffffffff8c946668 (rtnl_mutex){+.+.}-{3:3}, at: do_ipv6_setsockopt.constprop.0+0x2f6/0x4140 net/ipv6/ipv6_sockglue.c:417 1 lock held by syz-executor.5/10023: #0: ffffffff8c946668 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline] #0: ffffffff8c946668 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x3f9/0xad0 net/core/rtnetlink.c:5561 1 lock held by syz-executor.5/10029: #0: ffffffff8c946668 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline] #0: ffffffff8c946668 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x3f9/0xad0 net/core/rtnetlink.c:5561 1 lock held by syz-executor.2/10028: #0: ffffffff8c946668 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline] #0: ffffffff8c946668 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x3f9/0xad0 net/core/rtnetlink.c:5561 1 lock held by syz-executor.2/10046: #0: ffffffff8c946668 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline] #0: ffffffff8c946668 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x3f9/0xad0 net/core/rtnetlink.c:5561 1 lock held by syz-executor.3/10038: #0: ffffffff8c946668 (rtnl_mutex){+.+.}-{3:3}, at: sock_do_ioctl+0x1f2/0x2d0 net/socket.c:1050 1 lock held by syz-executor.3/10039: #0: ffffffff8c946668 (rtnl_mutex){+.+.}-{3:3}, at: sock_do_ioctl+0x1f2/0x2d0 net/socket.c:1050 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1660 Comm: khungtaskd Not tainted 5.11.0-rc2-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:79 [inline] dump_stack+0x107/0x163 lib/dump_stack.c:120 nmi_cpu_backtrace.cold+0x44/0xd7 lib/nmi_backtrace.c:105 nmi_trigger_cpumask_backtrace+0x1b3/0x230 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:209 [inline] watchdog+0xd43/0xfa0 kernel/hung_task.c:294 kthread+0x3b1/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 10000 Comm: syz-executor.1 Not tainted 5.11.0-rc2-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:lock_acquire+0x11/0x740 kernel/locking/lockdep.c:5405 Code: 88 ef 8c e8 41 7c 5c 00 e9 fb fe ff ff 66 90 66 2e 0f 1f 84 00 00 00 00 00 48 b8 00 00 00 00 00 fc ff df 41 57 41 89 d7 41 56 <41> 89 f6 41 55 49 89 fd 41 54 41 89 cc 55 44 89 c5 53 48 81 ec b0 RSP: 0018:ffffc90001e9eb50 EFLAGS: 00000246 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8880217f4668 RBP: ffff8880217f4600 R08: 0000000000000001 R09: 0000000000000000 R10: ffffed10042fe8c0 R11: 0000000000000000 R12: 0000000000000000 R13: dffffc0000000000 R14: ffff8880217f4600 R15: 0000000000000000 FS: 00007fa144f34700(0000) GS:ffff8880b9e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f78cb3db000 CR3: 00000000248d6000 CR4: 00000000001506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __mutex_lock_common kernel/locking/mutex.c:956 [inline] __mutex_lock+0x134/0x1110 kernel/locking/mutex.c:1103 tcf_idr_check_alloc+0x78/0x3b0 net/sched/act_api.c:549 tcf_police_init+0x347/0x13a0 net/sched/act_police.c:81 tcf_action_init_1+0x1a3/0x990 net/sched/act_api.c:1013 tcf_exts_validate+0x138/0x420 net/sched/cls_api.c:3046 u32_set_parms+0xb9/0xc60 net/sched/cls_u32.c:717 u32_change+0x1f13/0x3000 net/sched/cls_u32.c:1063 tc_new_tfilter+0x1394/0x2120 net/sched/cls_api.c:2127 rtnetlink_rcv_msg+0x80e/0xad0 net/core/rtnetlink.c:5555 netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2494 netlink_unicast_kernel net/netlink/af_netlink.c:1304 [inline] netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1330 netlink_sendmsg+0x856/0xd90 net/netlink/af_netlink.c:1919 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:672 ____sys_sendmsg+0x331/0x810 net/socket.c:2345 ___sys_sendmsg+0xf3/0x170 net/socket.c:2399 __sys_sendmmsg+0x195/0x470 net/socket.c:2489 __do_sys_sendmmsg net/socket.c:2518 [inline] __se_sys_sendmmsg net/socket.c:2515 [inline] __x64_sys_sendmmsg+0x99/0x100 net/socket.c:2515 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45e219 Code: 0d b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 db b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fa144f33c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000133 RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 000000000045e219 RDX: 010efe10675dec16 RSI: 0000000020000200 RDI: 0000000000000003 RBP: 000000000119c070 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000119c034 R13: 00000000016afb5f R14: 00007fa144f349c0 R15: 000000000119c034