bisecting fixing commit since f6d5cb9e2c06f7d583dd9f4f7cca21d13d78c32a building syzkaller on abf9ba4fc75d9b29af15625d44dcfc1360fad3b7 testing commit f6d5cb9e2c06f7d583dd9f4f7cca21d13d78c32a compiler: gcc version 8.4.1 20210217 (GCC) kernel signature: cc5873a84ea80c50298fc48dffaf0b6ec1e23f935c50d5d2313e744bdcc34ad2 all runs: crashed: INFO: task hung in rtnl_lock testing current HEAD b172b44fcb1771e083aad806fa96f3f60e2ddfac testing commit b172b44fcb1771e083aad806fa96f3f60e2ddfac compiler: gcc version 8.4.1 20210217 (GCC) kernel signature: 625e60f9e630657fcd9c0ff1941b668a37d123d4b63da36c3230c365ec672927 all runs: crashed: INFO: task hung in rtnl_lock revisions tested: 2, total time: 34m20.717947313s (build: 18m49.609590351s, test: 14m52.054425214s) the crash still happens on HEAD commit msg: Linux 4.19.206 crash: INFO: task hung in rtnl_lock Bluetooth: hci1: command 0x0406 tx timeout Bluetooth: hci5: command 0x0406 tx timeout Bluetooth: hci0: command 0x0406 tx timeout Bluetooth: hci4: command 0x0406 tx timeout Bluetooth: hci3: command 0x0406 tx timeout INFO: task kworker/1:0:19 blocked for more than 140 seconds. Not tainted 4.19.206-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/1:0 D24888 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:1015 [inline] __mutex_lock+0x4ba/0x1190 kernel/locking/mutex.c:1083 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1098 rtnl_lock+0x12/0x20 net/core/rtnetlink.c:77 addrconf_dad_work+0xa1/0xf70 net/ipv6/addrconf.c:3989 process_one_work+0x7b9/0x15a0 kernel/workqueue.c:2153 worker_thread+0x85/0xb60 kernel/workqueue.c:2296 kthread+0x347/0x410 kernel/kthread.c:259 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 INFO: task kworker/1:2:2789 blocked for more than 140 seconds. Not tainted 4.19.206-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/1:2 D26424 2789 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:1015 [inline] __mutex_lock+0x4ba/0x1190 kernel/locking/mutex.c:1083 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1098 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:2153 worker_thread+0x85/0xb60 kernel/workqueue.c:2296 kthread+0x347/0x410 kernel/kthread.c:259 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 INFO: task kworker/0:2:2866 blocked for more than 140 seconds. Not tainted 4.19.206-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/0:2 D25176 2866 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:1015 [inline] __mutex_lock+0x4ba/0x1190 kernel/locking/mutex.c:1083 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1098 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:2153 worker_thread+0x85/0xb60 kernel/workqueue.c:2296 kthread+0x347/0x410 kernel/kthread.c:259 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 INFO: task syz-executor.2:5915 blocked for more than 140 seconds. Not tainted 4.19.206-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.2 D23768 5915 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:1015 [inline] __mutex_lock+0x4ba/0x1190 kernel/locking/mutex.c:1083 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1098 rtnl_lock net/core/rtnetlink.c:77 [inline] rtnetlink_rcv_msg+0x301/0x950 net/core/rtnetlink.c:4779 netlink_rcv_skb+0x13e/0x3d0 net/netlink/af_netlink.c:2457 rtnetlink_rcv+0x10/0x20 net/core/rtnetlink.c:4800 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline] netlink_unicast+0x443/0x660 net/netlink/af_netlink.c:1346 netlink_sendmsg+0x667/0xc60 net/netlink/af_netlink.c:1911 sock_sendmsg_nosec net/socket.c:651 [inline] sock_sendmsg+0xac/0xf0 net/socket.c:661 __sys_sendto+0x1f2/0x2e0 net/socket.c:1899 __do_sys_sendto net/socket.c:1911 [inline] __se_sys_sendto net/socket.c:1907 [inline] __x64_sys_sendto+0xdc/0x1a0 net/socket.c:1907 do_syscall_64+0xd0/0x4e0 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x41832c Code: Bad RIP value. RSP: 002b:00007ffd8a866ef0 EFLAGS: 00000293 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 0000000001493720 RCX: 000000000041832c RDX: 0000000000000040 RSI: 0000000001493770 RDI: 0000000000000003 RBP: 0000000000000000 R08: 00007ffd8a866f34 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000003 R15: 0000000001493770 INFO: task syz-executor.0:5920 blocked for more than 140 seconds. Not tainted 4.19.206-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D23384 5920 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:1015 [inline] __mutex_lock+0x4ba/0x1190 kernel/locking/mutex.c:1083 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1098 rtnl_lock net/core/rtnetlink.c:77 [inline] rtnetlink_rcv_msg+0x301/0x950 net/core/rtnetlink.c:4779 netlink_rcv_skb+0x13e/0x3d0 net/netlink/af_netlink.c:2457 rtnetlink_rcv+0x10/0x20 net/core/rtnetlink.c:4800 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline] netlink_unicast+0x443/0x660 net/netlink/af_netlink.c:1346 netlink_sendmsg+0x667/0xc60 net/netlink/af_netlink.c:1911 sock_sendmsg_nosec net/socket.c:651 [inline] sock_sendmsg+0xac/0xf0 net/socket.c:661 __sys_sendto+0x1f2/0x2e0 net/socket.c:1899 __do_sys_sendto net/socket.c:1911 [inline] __se_sys_sendto net/socket.c:1907 [inline] __x64_sys_sendto+0xdc/0x1a0 net/socket.c:1907 do_syscall_64+0xd0/0x4e0 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x41832c Code: Bad RIP value. RSP: 002b:00007ffea89004b0 EFLAGS: 00000293 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 0000000001493720 RCX: 000000000041832c RDX: 0000000000000040 RSI: 0000000001493770 RDI: 0000000000000003 RBP: 0000000000000000 R08: 00007ffea89004f4 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000003 R15: 0000000001493770 INFO: task syz-executor.4:5924 blocked for more than 140 seconds. Not tainted 4.19.206-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.4 D23816 5924 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:1015 [inline] __mutex_lock+0x4ba/0x1190 kernel/locking/mutex.c:1083 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1098 rtnl_lock net/core/rtnetlink.c:77 [inline] rtnetlink_rcv_msg+0x301/0x950 net/core/rtnetlink.c:4779 netlink_rcv_skb+0x13e/0x3d0 net/netlink/af_netlink.c:2457 rtnetlink_rcv+0x10/0x20 net/core/rtnetlink.c:4800 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline] netlink_unicast+0x443/0x660 net/netlink/af_netlink.c:1346 netlink_sendmsg+0x667/0xc60 net/netlink/af_netlink.c:1911 sock_sendmsg_nosec net/socket.c:651 [inline] sock_sendmsg+0xac/0xf0 net/socket.c:661 __sys_sendto+0x1f2/0x2e0 net/socket.c:1899 __do_sys_sendto net/socket.c:1911 [inline] __se_sys_sendto net/socket.c:1907 [inline] __x64_sys_sendto+0xdc/0x1a0 net/socket.c:1907 do_syscall_64+0xd0/0x4e0 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x41832c Code: Bad RIP value. RSP: 002b:00007ffe0c473450 EFLAGS: 00000293 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 0000000001493720 RCX: 000000000041832c RDX: 0000000000000028 RSI: 0000000001493770 RDI: 0000000000000003 RBP: 0000000000000000 R08: 00007ffe0c473494 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000003 R15: 0000000001493770 INFO: task syz-executor.5:5926 blocked for more than 140 seconds. Not tainted 4.19.206-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.5 D23128 5926 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:1015 [inline] __mutex_lock+0x4ba/0x1190 kernel/locking/mutex.c:1083 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1098 rtnl_lock net/core/rtnetlink.c:77 [inline] rtnetlink_rcv_msg+0x301/0x950 net/core/rtnetlink.c:4779 netlink_rcv_skb+0x13e/0x3d0 net/netlink/af_netlink.c:2457 rtnetlink_rcv+0x10/0x20 net/core/rtnetlink.c:4800 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline] netlink_unicast+0x443/0x660 net/netlink/af_netlink.c:1346 netlink_sendmsg+0x667/0xc60 net/netlink/af_netlink.c:1911 sock_sendmsg_nosec net/socket.c:651 [inline] sock_sendmsg+0xac/0xf0 net/socket.c:661 __sys_sendto+0x1f2/0x2e0 net/socket.c:1899 __do_sys_sendto net/socket.c:1911 [inline] __se_sys_sendto net/socket.c:1907 [inline] __x64_sys_sendto+0xdc/0x1a0 net/socket.c:1907 do_syscall_64+0xd0/0x4e0 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x41832c Code: Bad RIP value. RSP: 002b:00007ffdb4235790 EFLAGS: 00000293 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 0000000001493720 RCX: 000000000041832c RDX: 0000000000000040 RSI: 0000000001493770 RDI: 0000000000000003 RBP: 0000000000000000 R08: 00007ffdb42357d4 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000003 R15: 0000000001493770 INFO: task syz-executor.1:5927 blocked for more than 140 seconds. Not tainted 4.19.206-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.1 D23368 5927 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:1015 [inline] __mutex_lock+0x4ba/0x1190 kernel/locking/mutex.c:1083 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1098 rtnl_lock net/core/rtnetlink.c:77 [inline] rtnetlink_rcv_msg+0x301/0x950 net/core/rtnetlink.c:4779 netlink_rcv_skb+0x13e/0x3d0 net/netlink/af_netlink.c:2457 rtnetlink_rcv+0x10/0x20 net/core/rtnetlink.c:4800 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline] netlink_unicast+0x443/0x660 net/netlink/af_netlink.c:1346 netlink_sendmsg+0x667/0xc60 net/netlink/af_netlink.c:1911 sock_sendmsg_nosec net/socket.c:651 [inline] sock_sendmsg+0xac/0xf0 net/socket.c:661 __sys_sendto+0x1f2/0x2e0 net/socket.c:1899 __do_sys_sendto net/socket.c:1911 [inline] __se_sys_sendto net/socket.c:1907 [inline] __x64_sys_sendto+0xdc/0x1a0 net/socket.c:1907 do_syscall_64+0xd0/0x4e0 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x41832c Code: Bad RIP value. RSP: 002b:00007ffc65383000 EFLAGS: 00000293 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 0000000001493720 RCX: 000000000041832c RDX: 0000000000000040 RSI: 0000000001493770 RDI: 0000000000000003 RBP: 0000000000000000 R08: 00007ffc65383044 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000003 R15: 0000000001493770 INFO: task kworker/0:3:6136 blocked for more than 140 seconds. Not tainted 4.19.206-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/0:3 D26104 6136 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:1015 [inline] __mutex_lock+0x4ba/0x1190 kernel/locking/mutex.c:1083 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1098 rtnl_lock+0x12/0x20 net/core/rtnetlink.c:77 addrconf_dad_work+0xa1/0xf70 net/ipv6/addrconf.c:3989 process_one_work+0x7b9/0x15a0 kernel/workqueue.c:2153 worker_thread+0x85/0xb60 kernel/workqueue.c:2296 kthread+0x347/0x410 kernel/kthread.c:259 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 INFO: task syz-executor.3:7234 blocked for more than 140 seconds. Not tainted 4.19.206-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.3 D25080 7234 5922 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:1015 [inline] __mutex_lock+0x4ba/0x1190 kernel/locking/mutex.c:1083 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1098 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+0xfb5/0x1590 net/sched/act_ife.c:580 tcf_action_init_1+0x8c6/0xbc0 net/sched/act_api.c:870 tcf_action_init+0x178/0x300 net/sched/act_api.c:936 tcf_action_add+0xf2/0x320 net/sched/act_api.c:1317 tc_ctl_action+0x28d/0x3d0 net/sched/act_api.c:1372 rtnetlink_rcv_msg+0x34f/0x950 net/core/rtnetlink.c:4782 netlink_rcv_skb+0x13e/0x3d0 net/netlink/af_netlink.c:2457 rtnetlink_rcv+0x10/0x20 net/core/rtnetlink.c:4800 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline] netlink_unicast+0x443/0x660 net/netlink/af_netlink.c:1346 netlink_sendmsg+0x667/0xc60 net/netlink/af_netlink.c:1911 sock_sendmsg_nosec net/socket.c:651 [inline] sock_sendmsg+0xac/0xf0 net/socket.c:661 ___sys_sendmsg+0x647/0x950 net/socket.c:2227 __sys_sendmsg+0xd9/0x180 net/socket.c:2265 __do_sys_sendmsg net/socket.c:2274 [inline] __se_sys_sendmsg net/socket.c:2272 [inline] __x64_sys_sendmsg+0x73/0xb0 net/socket.c:2272 do_syscall_64+0xd0/0x4e0 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x465109 Code: Bad RIP value. RSP: 002b:00007f68a95cb188 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 000000000055cf00 RCX: 0000000000465109 RDX: 0000000000000000 RSI: 0000000020000100 RDI: 0000000000000003 RBP: 00000000004af711 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000055cf00 R13: 00007ffd35d42bbf R14: 00007f68a95cb300 R15: 0000000000022000 Showing all locks held in the system: 3 locks held by kworker/1:0/19: #0: 0000000056744417 ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: process_one_work+0x6e8/0x15a0 kernel/workqueue.c:2124 #1: 000000005a2f6467 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}, at: process_one_work+0x71b/0x15a0 kernel/workqueue.c:2128 #2: 00000000f80701e2 (rtnl_mutex){+.+.}, at: rtnl_lock+0x12/0x20 net/core/rtnetlink.c:77 1 lock held by khungtaskd/1093: #0: 00000000aa9e18ad (rcu_read_lock){....}, at: debug_show_all_locks+0x5b/0x27a kernel/locking/lockdep.c:4443 3 locks held by kworker/1:2/2789: #0: 00000000d97cc268 ((wq_completion)"events"){+.+.}, at: process_one_work+0x6e8/0x15a0 kernel/workqueue.c:2124 #1: 000000008415d6a8 ((linkwatch_work).work){+.+.}, at: process_one_work+0x71b/0x15a0 kernel/workqueue.c:2128 #2: 00000000f80701e2 (rtnl_mutex){+.+.}, at: rtnl_lock+0x12/0x20 net/core/rtnetlink.c:77 3 locks held by kworker/0:2/2866: #0: 000000002067992f ((wq_completion)"events_power_efficient"){+.+.}, at: process_one_work+0x6e8/0x15a0 kernel/workqueue.c:2124 #1: 0000000043eec379 ((reg_check_chans).work){+.+.}, at: process_one_work+0x71b/0x15a0 kernel/workqueue.c:2128 #2: 00000000f80701e2 (rtnl_mutex){+.+.}, at: rtnl_lock+0x12/0x20 net/core/rtnetlink.c:77 1 lock held by in:imklog/5588: #0: 0000000047f0d196 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xa7/0xd0 fs/file.c:767 1 lock held by syz-executor.2/5915: #0: 00000000f80701e2 (rtnl_mutex){+.+.}, at: rtnl_lock net/core/rtnetlink.c:77 [inline] #0: 00000000f80701e2 (rtnl_mutex){+.+.}, at: rtnetlink_rcv_msg+0x301/0x950 net/core/rtnetlink.c:4779 1 lock held by syz-executor.0/5920: #0: 00000000f80701e2 (rtnl_mutex){+.+.}, at: rtnl_lock net/core/rtnetlink.c:77 [inline] #0: 00000000f80701e2 (rtnl_mutex){+.+.}, at: rtnetlink_rcv_msg+0x301/0x950 net/core/rtnetlink.c:4779 1 lock held by syz-executor.4/5924: #0: 00000000f80701e2 (rtnl_mutex){+.+.}, at: rtnl_lock net/core/rtnetlink.c:77 [inline] #0: 00000000f80701e2 (rtnl_mutex){+.+.}, at: rtnetlink_rcv_msg+0x301/0x950 net/core/rtnetlink.c:4779 1 lock held by syz-executor.5/5926: #0: 00000000f80701e2 (rtnl_mutex){+.+.}, at: rtnl_lock net/core/rtnetlink.c:77 [inline] #0: 00000000f80701e2 (rtnl_mutex){+.+.}, at: rtnetlink_rcv_msg+0x301/0x950 net/core/rtnetlink.c:4779 1 lock held by syz-executor.1/5927: #0: 00000000f80701e2 (rtnl_mutex){+.+.}, at: rtnl_lock net/core/rtnetlink.c:77 [inline] #0: 00000000f80701e2 (rtnl_mutex){+.+.}, at: rtnetlink_rcv_msg+0x301/0x950 net/core/rtnetlink.c:4779 3 locks held by kworker/0:3/6136: #0: 0000000056744417 ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: process_one_work+0x6e8/0x15a0 kernel/workqueue.c:2124 #1: 000000001289c827 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}, at: process_one_work+0x71b/0x15a0 kernel/workqueue.c:2128 #2: 00000000f80701e2 (rtnl_mutex){+.+.}, at: rtnl_lock+0x12/0x20 net/core/rtnetlink.c:77 1 lock held by syz-executor.3/7234: #0: 00000000f80701e2 (rtnl_mutex){+.+.}, at: rtnl_lock+0x12/0x20 net/core/rtnetlink.c:77 2 locks held by syz-executor.3/7237: 1 lock held by syz-executor.3/7243: #0: 00000000f80701e2 (rtnl_mutex){+.+.}, at: rtnl_lock net/core/rtnetlink.c:77 [inline] #0: 00000000f80701e2 (rtnl_mutex){+.+.}, at: rtnetlink_rcv_msg+0x301/0x950 net/core/rtnetlink.c:4779 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1093 Comm: khungtaskd Not tainted 4.19.206-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/0x226 lib/dump_stack.c:118 nmi_cpu_backtrace.cold.0+0x3c/0x78 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0xf5/0x120 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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 7237 Comm: syz-executor.3 Not tainted 4.19.206-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:hlock_class kernel/locking/lockdep.c:152 [inline] RIP: 0010:mark_lock+0x5e/0x12f0 kernel/locking/lockdep.c:3106 Code: 89 f3 48 83 ec 20 0f b6 04 02 84 c0 74 08 3c 01 0f 8e af 04 00 00 0f b7 43 20 66 a9 ff 1f 74 77 48 ba 00 00 00 00 00 fc ff df <4c> 89 c1 48 c1 e9 03 0f b6 14 11 84 d2 74 09 80 fa 03 0f 8e 98 04 RSP: 0018:ffff8881db386b98 EFLAGS: 00000002 RAX: 000000000000077a RBX: ffff8881e9ba4ab0 RCX: 0000000000000008 RDX: dffffc0000000000 RSI: ffff8881e9ba4ab0 RDI: ffff8881e9ba4200 RBP: ffff8881db386be0 R08: ffff8881e9ba4ad0 R09: 0000000000000001 R10: ffff8881e9ba4ab0 R11: ffff8881e9ba4a74 R12: ffff8881e9ba4ad2 R13: 0000000000000100 R14: 0000000000000008 R15: ffff8881e9ba4200 FS: 00007f68a95aa700(0000) GS:ffff8881f6800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000027f1848 CR3: 00000001daf71005 CR4: 00000000001606f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __lock_acquire+0x764/0x47c0 kernel/locking/lockdep.c:3377 lock_acquire+0x180/0x3a0 kernel/locking/lockdep.c:3908 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2d/0x40 kernel/locking/spinlock.c:144 spin_lock include/linux/spinlock.h:329 [inline] tcf_idr_check_alloc+0x85/0x2c0 net/sched/act_api.c:444 tcf_ife_init+0x30c/0x1590 net/sched/act_ife.c:514 tcf_action_init_1+0x8c6/0xbc0 net/sched/act_api.c:870 tcf_action_init+0x178/0x300 net/sched/act_api.c:936 tcf_action_add+0xf2/0x320 net/sched/act_api.c:1317 tc_ctl_action+0x28d/0x3d0 net/sched/act_api.c:1372 rtnetlink_rcv_msg+0x34f/0x950 net/core/rtnetlink.c:4782 netlink_rcv_skb+0x13e/0x3d0 net/netlink/af_netlink.c:2457 rtnetlink_rcv+0x10/0x20 net/core/rtnetlink.c:4800 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline] netlink_unicast+0x443/0x660 net/netlink/af_netlink.c:1346 netlink_sendmsg+0x667/0xc60 net/netlink/af_netlink.c:1911 sock_sendmsg_nosec net/socket.c:651 [inline] sock_sendmsg+0xac/0xf0 net/socket.c:661 ___sys_sendmsg+0x647/0x950 net/socket.c:2227 __sys_sendmsg+0xd9/0x180 net/socket.c:2265 __do_sys_sendmsg net/socket.c:2274 [inline] __se_sys_sendmsg net/socket.c:2272 [inline] __x64_sys_sendmsg+0x73/0xb0 net/socket.c:2272 do_syscall_64+0xd0/0x4e0 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x465109 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f68a95aa188 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 000000000055cfa0 RCX: 0000000000465109 RDX: 0000000000000000 RSI: 0000000020000100 RDI: 0000000000000004 RBP: 00000000004af711 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000055cfa0 R13: 00007ffd35d42bbf R14: 00007f68a95aa300 R15: 0000000000022000 ---------------- Code disassembly (best guess): 0: 89 f3 mov %esi,%ebx 2: 48 83 ec 20 sub $0x20,%rsp 6: 0f b6 04 02 movzbl (%rdx,%rax,1),%eax a: 84 c0 test %al,%al c: 74 08 je 0x16 e: 3c 01 cmp $0x1,%al 10: 0f 8e af 04 00 00 jle 0x4c5 16: 0f b7 43 20 movzwl 0x20(%rbx),%eax 1a: 66 a9 ff 1f test $0x1fff,%ax 1e: 74 77 je 0x97 20: 48 ba 00 00 00 00 00 movabs $0xdffffc0000000000,%rdx 27: fc ff df * 2a: 4c 89 c1 mov %r8,%rcx <-- trapping instruction 2d: 48 c1 e9 03 shr $0x3,%rcx 31: 0f b6 14 11 movzbl (%rcx,%rdx,1),%edx 35: 84 d2 test %dl,%dl 37: 74 09 je 0x42 39: 80 fa 03 cmp $0x3,%dl 3c: 0f .byte 0xf 3d: 8e .byte 0x8e 3e: 98 cwtl 3f: 04 .byte 0x4