INFO: task syz-executor727:6868 blocked for more than 143 seconds. Not tainted 5.9.0-rc8-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor727 state:D stack:25600 pid: 6868 ppid: 6866 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:3778 [inline] __schedule+0xec9/0x2280 kernel/sched/core.c:4527 schedule+0xd0/0x2a0 kernel/sched/core.c:4602 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4661 __mutex_lock_common kernel/locking/mutex.c:1033 [inline] __mutex_lock+0x3e2/0x10e0 kernel/locking/mutex.c:1103 tcf_action_init_1+0x747/0x990 net/sched/act_api.c:968 tcf_action_init+0x265/0x4b0 net/sched/act_api.c:1043 tcf_action_add+0xd9/0x360 net/sched/act_api.c:1456 tc_ctl_action+0x33a/0x439 net/sched/act_api.c:1509 rtnetlink_rcv_msg+0x44e/0xad0 net/core/rtnetlink.c:5563 netlink_rcv_skb+0x15a/0x430 net/netlink/af_netlink.c:2489 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:651 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:671 ____sys_sendmsg+0x6e8/0x810 net/socket.c:2353 ___sys_sendmsg+0xf3/0x170 net/socket.c:2407 __sys_sendmsg+0xe5/0x1b0 net/socket.c:2440 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x447b89 Code: Bad RIP value. RSP: 002b:00007f571c4a2ce8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00000000006dcc28 RCX: 0000000000447b89 RDX: 0000000000000000 RSI: 0000000020002980 RDI: 0000000000000003 RBP: 00000000006dcc20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006dcc2c R13: 00007ffc82ce23df R14: 00007f571c4a39c0 R15: 20c49ba5e353f7cf Showing all locks held in the system: 1 lock held by khungtaskd/1175: #0: ffffffff8a068480 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:5852 3 locks held by kworker/0:2/2661: #0: ffff88809a28b938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff88809a28b938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline] #0: ffff88809a28b938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline] #0: ffff88809a28b938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:616 [inline] #0: ffff88809a28b938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:643 [inline] #0: ffff88809a28b938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x82b/0x1670 kernel/workqueue.c:2240 #1: ffffc900089efda8 ((addr_chk_work).work){+.+.}-{0:0}, at: process_one_work+0x85f/0x1670 kernel/workqueue.c:2244 #2: ffffffff8b17a308 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_verify_work+0xa/0x20 net/ipv6/addrconf.c:4568 1 lock held by in:imklog/6558: #0: ffff8880a6d98170 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:930 1 lock held by syz-executor727/6868: #0: ffffffff8b17a308 (rtnl_mutex){+.+.}-{3:3}, at: tcf_action_init_1+0x747/0x990 net/sched/act_api.c:968 1 lock held by syz-executor727/6870: ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1175 Comm: khungtaskd Not tainted 5.9.0-rc8-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x198/0x1fd lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x70/0xb1 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1b3/0x223 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+0xd7d/0x1000 kernel/hung_task.c:295 kthread+0x3b5/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 6870 Comm: syz-executor727 Not tainted 5.9.0-rc8-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:lockdep_recursion_finish kernel/locking/lockdep.c:398 [inline] RIP: 0010:lock_is_held_type+0xa5/0xf0 kernel/locking/lockdep.c:5069 Code: bc 01 00 00 00 83 f9 ff 74 11 41 0f b6 46 22 45 31 e4 83 e0 03 39 c8 41 0f 94 c4 65 48 8b 14 25 c0 fe 01 00 8b 82 04 09 00 00 <83> e8 01 66 85 c0 89 82 04 09 00 00 75 27 4c 89 ff e8 d5 bb 23 f9 RSP: 0018:ffffc9000555ed40 EFLAGS: 00000046 RAX: 0000000000000001 RBX: 0000000000000002 RCX: ffffffff815c200f RDX: ffff888093b7c440 RSI: ffffffff8a0683c0 RDI: ffff888093b7cd70 RBP: ffff888093b7c440 R08: 0000000000000000 R09: ffffffff8b5cba8f R10: fffffbfff16b9751 R11: 0000000000000000 R12: 0000000000000000 R13: ffff888093b7cd48 R14: ffff888093b7cd70 R15: 0000000000000286 FS: 00007f571c482700(0000) GS:ffff8880ae400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f53247a4ab4 CR3: 000000009e7b1000 CR4: 00000000001506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_is_held include/linux/lockdep.h:267 [inline] rcu_read_lock_sched_held+0x3a/0xb0 kernel/rcu/update.c:136 trace_lock_release include/trace/events/lock.h:58 [inline] lock_release+0x6a1/0x8f0 kernel/locking/lockdep.c:5040 __mutex_unlock_slowpath+0x81/0x610 kernel/locking/mutex.c:1228 tcf_idr_check_alloc+0x29e/0x3b0 net/sched/act_api.c:508 tcf_connmark_init+0x2de/0x910 net/sched/act_connmark.c:124 tcf_action_init_1+0x63f/0x990 net/sched/act_api.c:990 tcf_action_init+0x265/0x4b0 net/sched/act_api.c:1043 tcf_action_add+0xd9/0x360 net/sched/act_api.c:1456 tc_ctl_action+0x33a/0x439 net/sched/act_api.c:1509 rtnetlink_rcv_msg+0x44e/0xad0 net/core/rtnetlink.c:5563 netlink_rcv_skb+0x15a/0x430 net/netlink/af_netlink.c:2489 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:651 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:671 ____sys_sendmsg+0x6e8/0x810 net/socket.c:2353 ___sys_sendmsg+0xf3/0x170 net/socket.c:2407 __sys_sendmsg+0xe5/0x1b0 net/socket.c:2440 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x447b89 Code: e8 4c b4 02 00 48 83 c4 18 c3 0f 1f 80 00 00 00 00 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 8b 07 fc ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f571c481ce8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00000000006dcc38 RCX: 0000000000447b89 RDX: 0000000000000000 RSI: 0000000020002980 RDI: 0000000000000004 RBP: 00000000006dcc30 R08: 0000000000000004 R09: 0000000000000000 R10: 0000000000000004 R11: 0000000000000246 R12: 00000000006dcc3c R13: 00007ffc82ce23df R14: 00007f571c4829c0 R15: 20c49ba5e353f7cf