bisecting fixing commit since f6d5cb9e2c06f7d583dd9f4f7cca21d13d78c32a building syzkaller on abf9ba4fc75d9b29af15625d44dcfc1360fad3b7 testing commit f6d5cb9e2c06f7d583dd9f4f7cca21d13d78c32a with gcc (GCC) 8.1.0 kernel signature: 5feafd8601703de7495e86615be5b01d59dc95a4d206e84b9fc50567fc5f37ab all runs: crashed: INFO: task hung in rtnl_lock testing current HEAD daefdc9eb24bfa11ab77a4b2a9c3923f1051fe0b testing commit daefdc9eb24bfa11ab77a4b2a9c3923f1051fe0b with gcc (GCC) 8.1.0 kernel signature: 8d2a3660d98efdf3f48e57f9b81e4695e00fc7ea551bb1dd9f1e14084b3ef8e0 all runs: crashed: INFO: task hung in rtnl_lock revisions tested: 2, total time: 33m58.491234983s (build: 19m40.651842176s, test: 13m35.715462004s) the crash still happens on HEAD commit msg: Linux 4.19.161 crash: INFO: task hung in rtnl_lock Bluetooth: hci1: command 0x0406 tx timeout Bluetooth: hci3: command 0x0406 tx timeout Bluetooth: hci0: command 0x0406 tx timeout Bluetooth: hci5: command 0x0406 tx timeout Bluetooth: hci2: command 0x0406 tx timeout INFO: task kworker/1:0:19 blocked for more than 140 seconds. Not tainted 4.19.161-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/1:0 D26416 19 2 0x80000000 Workqueue: ipv6_addrconf addrconf_dad_work Call Trace: context_switch kernel/sched/core.c:2828 [inline] __schedule+0x80c/0x1f70 kernel/sched/core.c:3517 schedule+0x7f/0x1b0 kernel/sched/core.c:3561 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3619 __mutex_lock_common kernel/locking/mutex.c:1002 [inline] __mutex_lock+0x4c3/0x1200 kernel/locking/mutex.c:1072 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087 rtnl_lock+0x12/0x20 net/core/rtnetlink.c:77 addrconf_dad_work+0xa1/0xf70 net/ipv6/addrconf.c:3988 process_one_work+0x7b9/0x15a0 kernel/workqueue.c:2155 worker_thread+0x85/0xb60 kernel/workqueue.c:2298 kthread+0x347/0x410 kernel/kthread.c:259 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 INFO: task kworker/1:2:2861 blocked for more than 140 seconds. Not tainted 4.19.161-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/1:2 D26272 2861 2 0x80000000 Workqueue: events_power_efficient reg_check_chans_work Call Trace: context_switch kernel/sched/core.c:2828 [inline] __schedule+0x80c/0x1f70 kernel/sched/core.c:3517 schedule+0x7f/0x1b0 kernel/sched/core.c:3561 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3619 __mutex_lock_common kernel/locking/mutex.c:1002 [inline] __mutex_lock+0x4c3/0x1200 kernel/locking/mutex.c:1072 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087 rtnl_lock+0x12/0x20 net/core/rtnetlink.c:77 reg_check_chans_work+0x73/0xb20 net/wireless/reg.c:2189 process_one_work+0x7b9/0x15a0 kernel/workqueue.c:2155 worker_thread+0x85/0xb60 kernel/workqueue.c:2298 kthread+0x347/0x410 kernel/kthread.c:259 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 INFO: task kworker/0:3:3411 blocked for more than 140 seconds. Not tainted 4.19.161-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/0:3 D25024 3411 2 0x80000000 Workqueue: ipv6_addrconf addrconf_dad_work Call Trace: context_switch kernel/sched/core.c:2828 [inline] __schedule+0x80c/0x1f70 kernel/sched/core.c:3517 schedule+0x7f/0x1b0 kernel/sched/core.c:3561 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3619 __mutex_lock_common kernel/locking/mutex.c:1002 [inline] __mutex_lock+0x4c3/0x1200 kernel/locking/mutex.c:1072 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087 rtnl_lock+0x12/0x20 net/core/rtnetlink.c:77 addrconf_dad_work+0xa1/0xf70 net/ipv6/addrconf.c:3988 process_one_work+0x7b9/0x15a0 kernel/workqueue.c:2155 worker_thread+0x85/0xb60 kernel/workqueue.c:2298 kthread+0x347/0x410 kernel/kthread.c:259 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 INFO: task syz-executor.0:5962 blocked for more than 140 seconds. Not tainted 4.19.161-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D23800 5962 1 0x00000004 Call Trace: context_switch kernel/sched/core.c:2828 [inline] __schedule+0x80c/0x1f70 kernel/sched/core.c:3517 schedule+0x7f/0x1b0 kernel/sched/core.c:3561 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3619 __mutex_lock_common kernel/locking/mutex.c:1002 [inline] __mutex_lock+0x4c3/0x1200 kernel/locking/mutex.c:1072 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087 rtnl_lock net/core/rtnetlink.c:77 [inline] rtnetlink_rcv_msg+0x301/0x950 net/core/rtnetlink.c:4775 netlink_rcv_skb+0x13e/0x3d0 net/netlink/af_netlink.c:2455 rtnetlink_rcv+0x10/0x20 net/core/rtnetlink.c:4796 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x443/0x660 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x666/0xc50 net/netlink/af_netlink.c:1909 sock_sendmsg_nosec net/socket.c:622 [inline] sock_sendmsg+0xac/0xf0 net/socket.c:632 __sys_sendto+0x1f2/0x2e0 net/socket.c:1787 __do_sys_sendto net/socket.c:1799 [inline] __se_sys_sendto net/socket.c:1795 [inline] __x64_sys_sendto+0xdc/0x1a0 net/socket.c:1795 do_syscall_64+0xd0/0x4e0 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x417087 Code: Bad RIP value. RSP: 002b:00007ffcbc8bfc60 EFLAGS: 00000293 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00000000016a3700 RCX: 0000000000417087 RDX: 0000000000000028 RSI: 00000000016a3750 RDI: 0000000000000003 RBP: 0000000000000000 R08: 00007ffcbc8bfc70 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000 R13: 0000000000000000 R14: 00000000016a3750 R15: 0000000000000003 INFO: task syz-executor.2:5963 blocked for more than 140 seconds. Not tainted 4.19.161-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.2 D23736 5963 1 0x00000004 Call Trace: context_switch kernel/sched/core.c:2828 [inline] __schedule+0x80c/0x1f70 kernel/sched/core.c:3517 schedule+0x7f/0x1b0 kernel/sched/core.c:3561 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3619 __mutex_lock_common kernel/locking/mutex.c:1002 [inline] __mutex_lock+0x4c3/0x1200 kernel/locking/mutex.c:1072 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087 rtnl_lock net/core/rtnetlink.c:77 [inline] rtnetlink_rcv_msg+0x301/0x950 net/core/rtnetlink.c:4775 netlink_rcv_skb+0x13e/0x3d0 net/netlink/af_netlink.c:2455 rtnetlink_rcv+0x10/0x20 net/core/rtnetlink.c:4796 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x443/0x660 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x666/0xc50 net/netlink/af_netlink.c:1909 sock_sendmsg_nosec net/socket.c:622 [inline] sock_sendmsg+0xac/0xf0 net/socket.c:632 __sys_sendto+0x1f2/0x2e0 net/socket.c:1787 __do_sys_sendto net/socket.c:1799 [inline] __se_sys_sendto net/socket.c:1795 [inline] __x64_sys_sendto+0xdc/0x1a0 net/socket.c:1795 do_syscall_64+0xd0/0x4e0 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x417087 Code: Bad RIP value. RSP: 002b:00007ffcc67fe920 EFLAGS: 00000293 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00000000016a3700 RCX: 0000000000417087 RDX: 0000000000000040 RSI: 00000000016a3750 RDI: 0000000000000003 RBP: 0000000000000000 R08: 00007ffcc67fe930 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000 R13: 0000000000000000 R14: 00000000016a3750 R15: 0000000000000003 INFO: task syz-executor.3:5965 blocked for more than 140 seconds. Not tainted 4.19.161-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.3 D23776 5965 1 0x00000004 Call Trace: context_switch kernel/sched/core.c:2828 [inline] __schedule+0x80c/0x1f70 kernel/sched/core.c:3517 schedule+0x7f/0x1b0 kernel/sched/core.c:3561 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3619 __mutex_lock_common kernel/locking/mutex.c:1002 [inline] __mutex_lock+0x4c3/0x1200 kernel/locking/mutex.c:1072 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087 rtnl_lock net/core/rtnetlink.c:77 [inline] rtnetlink_rcv_msg+0x301/0x950 net/core/rtnetlink.c:4775 netlink_rcv_skb+0x13e/0x3d0 net/netlink/af_netlink.c:2455 rtnetlink_rcv+0x10/0x20 net/core/rtnetlink.c:4796 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x443/0x660 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x666/0xc50 net/netlink/af_netlink.c:1909 sock_sendmsg_nosec net/socket.c:622 [inline] sock_sendmsg+0xac/0xf0 net/socket.c:632 __sys_sendto+0x1f2/0x2e0 net/socket.c:1787 __do_sys_sendto net/socket.c:1799 [inline] __se_sys_sendto net/socket.c:1795 [inline] __x64_sys_sendto+0xdc/0x1a0 net/socket.c:1795 do_syscall_64+0xd0/0x4e0 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x417087 Code: Bad RIP value. RSP: 002b:00007ffe4e314330 EFLAGS: 00000293 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00000000016a3700 RCX: 0000000000417087 RDX: 0000000000000020 RSI: 00000000016a3750 RDI: 0000000000000003 RBP: 0000000000000000 R08: 00007ffe4e314340 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000 R13: 0000000000000000 R14: 00000000016a3750 R15: 0000000000000003 INFO: task syz-executor.4:5967 blocked for more than 140 seconds. Not tainted 4.19.161-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.4 D23760 5967 1 0x00000004 Call Trace: context_switch kernel/sched/core.c:2828 [inline] __schedule+0x80c/0x1f70 kernel/sched/core.c:3517 schedule+0x7f/0x1b0 kernel/sched/core.c:3561 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3619 __mutex_lock_common kernel/locking/mutex.c:1002 [inline] __mutex_lock+0x4c3/0x1200 kernel/locking/mutex.c:1072 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087 rtnl_lock net/core/rtnetlink.c:77 [inline] rtnetlink_rcv_msg+0x301/0x950 net/core/rtnetlink.c:4775 netlink_rcv_skb+0x13e/0x3d0 net/netlink/af_netlink.c:2455 rtnetlink_rcv+0x10/0x20 net/core/rtnetlink.c:4796 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x443/0x660 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x666/0xc50 net/netlink/af_netlink.c:1909 sock_sendmsg_nosec net/socket.c:622 [inline] sock_sendmsg+0xac/0xf0 net/socket.c:632 __sys_sendto+0x1f2/0x2e0 net/socket.c:1787 __do_sys_sendto net/socket.c:1799 [inline] __se_sys_sendto net/socket.c:1795 [inline] __x64_sys_sendto+0xdc/0x1a0 net/socket.c:1795 do_syscall_64+0xd0/0x4e0 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x417087 Code: Bad RIP value. RSP: 002b:00007ffef0c56020 EFLAGS: 00000293 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00000000016a3700 RCX: 0000000000417087 RDX: 0000000000000040 RSI: 00000000016a3750 RDI: 0000000000000003 RBP: 0000000000000000 R08: 00007ffef0c56030 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000 R13: 0000000000000000 R14: 00000000016a3750 R15: 0000000000000003 INFO: task syz-executor.1:5970 blocked for more than 140 seconds. Not tainted 4.19.161-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.1 D23376 5970 1 0x00000004 Call Trace: context_switch kernel/sched/core.c:2828 [inline] __schedule+0x80c/0x1f70 kernel/sched/core.c:3517 schedule+0x7f/0x1b0 kernel/sched/core.c:3561 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3619 __mutex_lock_common kernel/locking/mutex.c:1002 [inline] __mutex_lock+0x4c3/0x1200 kernel/locking/mutex.c:1072 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087 rtnl_lock net/core/rtnetlink.c:77 [inline] rtnetlink_rcv_msg+0x301/0x950 net/core/rtnetlink.c:4775 netlink_rcv_skb+0x13e/0x3d0 net/netlink/af_netlink.c:2455 rtnetlink_rcv+0x10/0x20 net/core/rtnetlink.c:4796 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x443/0x660 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x666/0xc50 net/netlink/af_netlink.c:1909 sock_sendmsg_nosec net/socket.c:622 [inline] sock_sendmsg+0xac/0xf0 net/socket.c:632 __sys_sendto+0x1f2/0x2e0 net/socket.c:1787 __do_sys_sendto net/socket.c:1799 [inline] __se_sys_sendto net/socket.c:1795 [inline] __x64_sys_sendto+0xdc/0x1a0 net/socket.c:1795 do_syscall_64+0xd0/0x4e0 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x417087 Code: Bad RIP value. RSP: 002b:00007ffe95e555d0 EFLAGS: 00000293 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00000000016a3700 RCX: 0000000000417087 RDX: 0000000000000028 RSI: 00000000016a3750 RDI: 0000000000000003 RBP: 0000000000000000 R08: 00007ffe95e555e0 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000 R13: 0000000000000000 R14: 00000000016a3750 R15: 0000000000000003 INFO: task kworker/1:3:7200 blocked for more than 140 seconds. Not tainted 4.19.161-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/1:3 D26592 7200 2 0x80000000 Workqueue: events linkwatch_event Call Trace: context_switch kernel/sched/core.c:2828 [inline] __schedule+0x80c/0x1f70 kernel/sched/core.c:3517 schedule+0x7f/0x1b0 kernel/sched/core.c:3561 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3619 __mutex_lock_common kernel/locking/mutex.c:1002 [inline] __mutex_lock+0x4c3/0x1200 kernel/locking/mutex.c:1072 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087 rtnl_lock+0x12/0x20 net/core/rtnetlink.c:77 linkwatch_event+0x9/0x50 net/core/link_watch.c:236 process_one_work+0x7b9/0x15a0 kernel/workqueue.c:2155 worker_thread+0x85/0xb60 kernel/workqueue.c:2298 kthread+0x347/0x410 kernel/kthread.c:259 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 INFO: task syz-executor.5:7275 blocked for more than 140 seconds. Not tainted 4.19.161-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.5 D24856 7275 5969 0x00000004 Call Trace: context_switch kernel/sched/core.c:2828 [inline] __schedule+0x80c/0x1f70 kernel/sched/core.c:3517 schedule+0x7f/0x1b0 kernel/sched/core.c:3561 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3619 __mutex_lock_common kernel/locking/mutex.c:1002 [inline] __mutex_lock+0x4c3/0x1200 kernel/locking/mutex.c:1072 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087 rtnl_lock+0x12/0x20 net/core/rtnetlink.c:77 load_metaops_and_vet net/sched/act_ife.c:281 [inline] populate_metalist net/sched/act_ife.c:456 [inline] tcf_ife_init+0xfa3/0x1570 net/sched/act_ife.c:580 tcf_action_init_1+0x70e/0xb40 net/sched/act_api.c:870 tcf_action_init+0x178/0x300 net/sched/act_api.c:933 tcf_action_add+0xf2/0x320 net/sched/act_api.c:1314 tc_ctl_action+0x28d/0x3c6 net/sched/act_api.c:1369 rtnetlink_rcv_msg+0x34f/0x950 net/core/rtnetlink.c:4778 netlink_rcv_skb+0x13e/0x3d0 net/netlink/af_netlink.c:2455 rtnetlink_rcv+0x10/0x20 net/core/rtnetlink.c:4796 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x443/0x660 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x666/0xc50 net/netlink/af_netlink.c:1909 sock_sendmsg_nosec net/socket.c:622 [inline] sock_sendmsg+0xac/0xf0 net/socket.c:632 ___sys_sendmsg+0x647/0x950 net/socket.c:2115 __sys_sendmsg+0xd9/0x180 net/socket.c:2153 __do_sys_sendmsg net/socket.c:2162 [inline] __se_sys_sendmsg net/socket.c:2160 [inline] __x64_sys_sendmsg+0x73/0xb0 net/socket.c:2160 do_syscall_64+0xd0/0x4e0 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45d5b9 Code: Bad RIP value. RSP: 002b:00007fb2cd87bc78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 000000000002cec0 RCX: 000000000045d5b9 RDX: 0000000000000000 RSI: 0000000020000100 RDI: 0000000000000003 RBP: 000000000118cf80 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118cf4c R13: 00007ffda795ad5f R14: 00007fb2cd87c9c0 R15: 000000000118cf4c Showing all locks held in the system: 3 locks held by kworker/1:0/19: #0: 000000005e28a5ef ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: process_one_work+0x6e8/0x15a0 kernel/workqueue.c:2126 #1: 000000008bcb7da7 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}, at: process_one_work+0x71b/0x15a0 kernel/workqueue.c:2130 #2: 000000009d886188 (rtnl_mutex){+.+.}, at: rtnl_lock+0x12/0x20 net/core/rtnetlink.c:77 1 lock held by khungtaskd/1087: #0: 00000000412e6225 (rcu_read_lock){....}, at: debug_show_all_locks+0x5b/0x27a kernel/locking/lockdep.c:4442 3 locks held by kworker/1:2/2861: #0: 000000003d5cee9b ((wq_completion)"events_power_efficient"){+.+.}, at: process_one_work+0x6e8/0x15a0 kernel/workqueue.c:2126 #1: 0000000054be77d8 ((reg_check_chans).work){+.+.}, at: process_one_work+0x71b/0x15a0 kernel/workqueue.c:2130 #2: 000000009d886188 (rtnl_mutex){+.+.}, at: rtnl_lock+0x12/0x20 net/core/rtnetlink.c:77 3 locks held by kworker/0:3/3411: #0: 000000005e28a5ef ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: process_one_work+0x6e8/0x15a0 kernel/workqueue.c:2126 #1: 0000000057721803 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}, at: process_one_work+0x71b/0x15a0 kernel/workqueue.c:2130 #2: 000000009d886188 (rtnl_mutex){+.+.}, at: rtnl_lock+0x12/0x20 net/core/rtnetlink.c:77 1 lock held by in:imklog/5565: #0: 00000000587007f9 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xa7/0xd0 fs/file.c:767 1 lock held by syz-executor.0/5962: #0: 000000009d886188 (rtnl_mutex){+.+.}, at: rtnl_lock net/core/rtnetlink.c:77 [inline] #0: 000000009d886188 (rtnl_mutex){+.+.}, at: rtnetlink_rcv_msg+0x301/0x950 net/core/rtnetlink.c:4775 1 lock held by syz-executor.2/5963: #0: 000000009d886188 (rtnl_mutex){+.+.}, at: rtnl_lock net/core/rtnetlink.c:77 [inline] #0: 000000009d886188 (rtnl_mutex){+.+.}, at: rtnetlink_rcv_msg+0x301/0x950 net/core/rtnetlink.c:4775 1 lock held by syz-executor.3/5965: #0: 000000009d886188 (rtnl_mutex){+.+.}, at: rtnl_lock net/core/rtnetlink.c:77 [inline] #0: 000000009d886188 (rtnl_mutex){+.+.}, at: rtnetlink_rcv_msg+0x301/0x950 net/core/rtnetlink.c:4775 1 lock held by syz-executor.4/5967: #0: 000000009d886188 (rtnl_mutex){+.+.}, at: rtnl_lock net/core/rtnetlink.c:77 [inline] #0: 000000009d886188 (rtnl_mutex){+.+.}, at: rtnetlink_rcv_msg+0x301/0x950 net/core/rtnetlink.c:4775 1 lock held by syz-executor.1/5970: #0: 000000009d886188 (rtnl_mutex){+.+.}, at: rtnl_lock net/core/rtnetlink.c:77 [inline] #0: 000000009d886188 (rtnl_mutex){+.+.}, at: rtnetlink_rcv_msg+0x301/0x950 net/core/rtnetlink.c:4775 3 locks held by kworker/1:3/7200: #0: 00000000692f100d ((wq_completion)"events"){+.+.}, at: process_one_work+0x6e8/0x15a0 kernel/workqueue.c:2126 #1: 0000000034d42b3a ((linkwatch_work).work){+.+.}, at: process_one_work+0x71b/0x15a0 kernel/workqueue.c:2130 #2: 000000009d886188 (rtnl_mutex){+.+.}, at: rtnl_lock+0x12/0x20 net/core/rtnetlink.c:77 1 lock held by syz-executor.5/7275: #0: 000000009d886188 (rtnl_mutex){+.+.}, at: rtnl_lock+0x12/0x20 net/core/rtnetlink.c:77 2 locks held by syz-executor.5/7277: 1 lock held by syz-executor.5/7283: #0: 000000009d886188 (rtnl_mutex){+.+.}, at: rtnl_lock net/core/rtnetlink.c:77 [inline] #0: 000000009d886188 (rtnl_mutex){+.+.}, at: rtnetlink_rcv_msg+0x301/0x950 net/core/rtnetlink.c:4775 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1087 Comm: khungtaskd Not tainted 4.19.161-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+0x17c/0x22a lib/dump_stack.c:118 nmi_cpu_backtrace.cold.0+0x3c/0x78 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0xf5/0x119 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:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:203 [inline] watchdog+0x5c3/0xb40 kernel/hung_task.c:287 kthread+0x347/0x410 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: 7277 Comm: syz-executor.5 Not tainted 4.19.161-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:find_held_lock+0x2a/0x300 kernel/locking/lockdep.c:3513 Code: 55 48 89 e5 41 57 49 89 f7 41 56 41 89 d6 41 55 44 8d 6a ff 49 63 c5 41 54 48 8d 04 80 53 48 8d 9c c7 88 08 00 00 48 83 ec 10 <48> 89 4d d0 48 b8 00 00 00 00 00 fc ff df 48 8d 7b 10 48 89 fa 48 RSP: 0018:ffff8881d779ed78 EFLAGS: 00000086 RAX: 0000000000000005 RBX: ffff8881ced22db0 RCX: ffff8881d779edf8 RDX: 0000000000000002 RSI: ffff8881ed565418 RDI: ffff8881ced22500 RBP: ffff8881d779edb0 R08: 0000000000000000 R09: ffff8881ed565478 R10: 0000000000000000 R11: 0000000000000040 R12: ffff8881ed565418 R13: 0000000000000001 R14: 0000000000000002 R15: ffff8881ed565418 FS: 00007fb2cd85b700(0000) GS:ffff8881f6900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000564dcc5fcb18 CR3: 00000001d68d4003 CR4: 00000000001606e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __lock_release kernel/locking/lockdep.c:3676 [inline] lock_release+0x257/0x840 kernel/locking/lockdep.c:3926 __raw_spin_unlock include/linux/spinlock_api_smp.h:150 [inline] _raw_spin_unlock+0x1a/0x50 kernel/locking/spinlock.c:176 spin_unlock include/linux/spinlock.h:369 [inline] tcf_idr_check_alloc+0x7d/0x2c0 net/sched/act_api.c:451 tcf_ife_init+0x30c/0x1570 net/sched/act_ife.c:514 tcf_action_init_1+0x70e/0xb40 net/sched/act_api.c:870 tcf_action_init+0x178/0x300 net/sched/act_api.c:933 tcf_action_add+0xf2/0x320 net/sched/act_api.c:1314 tc_ctl_action+0x28d/0x3c6 net/sched/act_api.c:1369 rtnetlink_rcv_msg+0x34f/0x950 net/core/rtnetlink.c:4778 netlink_rcv_skb+0x13e/0x3d0 net/netlink/af_netlink.c:2455 rtnetlink_rcv+0x10/0x20 net/core/rtnetlink.c:4796 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x443/0x660 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x666/0xc50 net/netlink/af_netlink.c:1909 sock_sendmsg_nosec net/socket.c:622 [inline] sock_sendmsg+0xac/0xf0 net/socket.c:632 ___sys_sendmsg+0x647/0x950 net/socket.c:2115 __sys_sendmsg+0xd9/0x180 net/socket.c:2153 __do_sys_sendmsg net/socket.c:2162 [inline] __se_sys_sendmsg net/socket.c:2160 [inline] __x64_sys_sendmsg+0x73/0xb0 net/socket.c:2160 do_syscall_64+0xd0/0x4e0 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45d5b9 Code: 5d 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 2b b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fb2cd85ac78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 000000000002cec0 RCX: 000000000045d5b9 RDX: 0000000000000000 RSI: 0000000020000100 RDI: 0000000000000004 RBP: 000000000118d020 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118cfec R13: 00007ffda795ad5f R14: 00007fb2cd85b9c0 R15: 000000000118cfec