bisecting fixing commit since 5b7a52cd2eef952cee8a72512ef370bcdef46636 building syzkaller on 94942294277bf7550b12322d282159551521258b testing commit 5b7a52cd2eef952cee8a72512ef370bcdef46636 with gcc (GCC) 8.1.0 kernel signature: f26f1ce495159d52cff9f6f7b7f1fb7e19efd2fe9484de0e59856200e5bb2168 all runs: crashed: INFO: task hung in rtnl_lock testing current HEAD 87335852c5d9ec629f80bb2257b9a9945962b719 testing commit 87335852c5d9ec629f80bb2257b9a9945962b719 with gcc (GCC) 8.1.0 kernel signature: 86b82ff5a7c3c0c96e8c624dacf51d9abe5233a3565c395d7c90c040eb458437 all runs: crashed: INFO: task hung in rtnl_lock revisions tested: 2, total time: 33m27.661893573s (build: 19m29.175040112s, test: 13m29.934120518s) the crash still happens on HEAD commit msg: Linux 4.14.209 crash: INFO: task hung in rtnl_lock Bluetooth: hci3 command 0x0406 tx timeout Bluetooth: hci1 command 0x0406 tx timeout Bluetooth: hci4 command 0x0406 tx timeout Bluetooth: hci0 command 0x0406 tx timeout Bluetooth: hci5 command 0x0406 tx timeout INFO: task kworker/u4:0:5 blocked for more than 140 seconds. Not tainted 4.14.209-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/u4:0 D25728 5 2 0x80000000 Workqueue: cfg80211 cfg80211_event_work Call Trace: context_switch kernel/sched/core.c:2808 [inline] __schedule+0x824/0x1ee0 kernel/sched/core.c:3384 schedule+0x7f/0x1b0 kernel/sched/core.c:3428 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3486 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x519/0x1490 kernel/locking/mutex.c:893 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908 rtnl_lock+0x12/0x20 net/core/rtnetlink.c:72 cfg80211_event_work+0xd/0x30 net/wireless/core.c:304 process_one_work+0x74f/0x1620 kernel/workqueue.c:2116 worker_thread+0xcc/0xed0 kernel/workqueue.c:2250 kthread+0x338/0x400 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 INFO: task kworker/1:1:23 blocked for more than 140 seconds. Not tainted 4.14.209-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/1:1 D25552 23 2 0x80000000 Workqueue: events linkwatch_event Call Trace: context_switch kernel/sched/core.c:2808 [inline] __schedule+0x824/0x1ee0 kernel/sched/core.c:3384 schedule+0x7f/0x1b0 kernel/sched/core.c:3428 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3486 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x519/0x1490 kernel/locking/mutex.c:893 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908 rtnl_lock+0x12/0x20 net/core/rtnetlink.c:72 linkwatch_event+0x9/0x50 net/core/link_watch.c:236 process_one_work+0x74f/0x1620 kernel/workqueue.c:2116 worker_thread+0xcc/0xed0 kernel/workqueue.c:2250 kthread+0x338/0x400 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 INFO: task kworker/0:1:24 blocked for more than 140 seconds. Not tainted 4.14.209-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/0:1 D26240 24 2 0x80000000 Workqueue: ipv6_addrconf addrconf_dad_work Call Trace: context_switch kernel/sched/core.c:2808 [inline] __schedule+0x824/0x1ee0 kernel/sched/core.c:3384 schedule+0x7f/0x1b0 kernel/sched/core.c:3428 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3486 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x519/0x1490 kernel/locking/mutex.c:893 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908 rtnl_lock+0x12/0x20 net/core/rtnetlink.c:72 addrconf_dad_work+0x8f/0xfa0 net/ipv6/addrconf.c:3917 process_one_work+0x74f/0x1620 kernel/workqueue.c:2116 worker_thread+0xcc/0xed0 kernel/workqueue.c:2250 kthread+0x338/0x400 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 INFO: task kworker/0:2:3617 blocked for more than 140 seconds. Not tainted 4.14.209-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/0:2 D26840 3617 2 0x80000000 Workqueue: events disconnect_work Call Trace: context_switch kernel/sched/core.c:2808 [inline] __schedule+0x824/0x1ee0 kernel/sched/core.c:3384 schedule+0x7f/0x1b0 kernel/sched/core.c:3428 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3486 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x519/0x1490 kernel/locking/mutex.c:893 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908 rtnl_lock+0x12/0x20 net/core/rtnetlink.c:72 disconnect_work+0x16/0x1b0 net/wireless/sme.c:664 process_one_work+0x74f/0x1620 kernel/workqueue.c:2116 worker_thread+0xcc/0xed0 kernel/workqueue.c:2250 kthread+0x338/0x400 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 INFO: task kworker/1:2:4304 blocked for more than 140 seconds. Not tainted 4.14.209-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/1:2 D27368 4304 2 0x80000000 Workqueue: events_power_efficient reg_check_chans_work Call Trace: context_switch kernel/sched/core.c:2808 [inline] __schedule+0x824/0x1ee0 kernel/sched/core.c:3384 schedule+0x7f/0x1b0 kernel/sched/core.c:3428 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3486 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x519/0x1490 kernel/locking/mutex.c:893 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908 rtnl_lock+0x12/0x20 net/core/rtnetlink.c:72 reg_check_chans_work+0x73/0xc60 net/wireless/reg.c:1655 process_one_work+0x74f/0x1620 kernel/workqueue.c:2116 worker_thread+0xcc/0xed0 kernel/workqueue.c:2250 kthread+0x338/0x400 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 INFO: task kworker/1:4:8199 blocked for more than 140 seconds. Not tainted 4.14.209-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/1:4 D27208 8199 2 0x80000000 Workqueue: ipv6_addrconf addrconf_dad_work Call Trace: context_switch kernel/sched/core.c:2808 [inline] __schedule+0x824/0x1ee0 kernel/sched/core.c:3384 schedule+0x7f/0x1b0 kernel/sched/core.c:3428 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3486 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x519/0x1490 kernel/locking/mutex.c:893 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908 rtnl_lock+0x12/0x20 net/core/rtnetlink.c:72 addrconf_dad_work+0x8f/0xfa0 net/ipv6/addrconf.c:3917 process_one_work+0x74f/0x1620 kernel/workqueue.c:2116 worker_thread+0xcc/0xed0 kernel/workqueue.c:2250 kthread+0x338/0x400 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 INFO: task syz-executor.3:8379 blocked for more than 140 seconds. Not tainted 4.14.209-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.3 D24784 8379 1 0x00000004 Call Trace: context_switch kernel/sched/core.c:2808 [inline] __schedule+0x824/0x1ee0 kernel/sched/core.c:3384 schedule+0x7f/0x1b0 kernel/sched/core.c:3428 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3486 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x519/0x1490 kernel/locking/mutex.c:893 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908 rtnl_lock net/core/rtnetlink.c:72 [inline] rtnetlink_rcv_msg+0x2c0/0x9e0 net/core/rtnetlink.c:4311 netlink_rcv_skb+0x12f/0x3b0 net/netlink/af_netlink.c:2433 rtnetlink_rcv+0x10/0x20 net/core/rtnetlink.c:4328 netlink_unicast_kernel net/netlink/af_netlink.c:1287 [inline] netlink_unicast+0x40b/0x610 net/netlink/af_netlink.c:1313 netlink_sendmsg+0x657/0xc60 net/netlink/af_netlink.c:1878 sock_sendmsg_nosec net/socket.c:646 [inline] sock_sendmsg+0xac/0xf0 net/socket.c:656 SYSC_sendto net/socket.c:1763 [inline] SyS_sendto+0x1e4/0x2c0 net/socket.c:1731 do_syscall_64+0x1c7/0x5b0 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x4178c7 RSP: 002b:00007ffe4e3b6940 EFLAGS: 00000293 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00000000016a4300 RCX: 00000000004178c7 RDX: 0000000000000020 RSI: 00000000016a4350 RDI: 0000000000000003 RBP: 0000000000000000 R08: 00007ffe4e3b6950 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000 R13: 0000000000000000 R14: 00000000016a4350 R15: 0000000000000003 INFO: task syz-executor.2:8382 blocked for more than 140 seconds. Not tainted 4.14.209-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.2 D24192 8382 1 0x00000004 Call Trace: context_switch kernel/sched/core.c:2808 [inline] __schedule+0x824/0x1ee0 kernel/sched/core.c:3384 schedule+0x7f/0x1b0 kernel/sched/core.c:3428 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3486 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x519/0x1490 kernel/locking/mutex.c:893 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908 genl_lock net/netlink/genetlink.c:33 [inline] genl_rcv_msg+0x10e/0x140 net/netlink/genetlink.c:623 netlink_rcv_skb+0x12f/0x3b0 net/netlink/af_netlink.c:2433 genl_rcv+0x23/0x40 net/netlink/genetlink.c:636 netlink_unicast_kernel net/netlink/af_netlink.c:1287 [inline] netlink_unicast+0x40b/0x610 net/netlink/af_netlink.c:1313 netlink_sendmsg+0x657/0xc60 net/netlink/af_netlink.c:1878 sock_sendmsg_nosec net/socket.c:646 [inline] sock_sendmsg+0xac/0xf0 net/socket.c:656 SYSC_sendto net/socket.c:1763 [inline] SyS_sendto+0x1e4/0x2c0 net/socket.c:1731 do_syscall_64+0x1c7/0x5b0 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x4178c7 RSP: 002b:00007ffd7e9b8940 EFLAGS: 00000293 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00000000016a4300 RCX: 00000000004178c7 RDX: 0000000000000024 RSI: 00000000016a4350 RDI: 0000000000000003 RBP: 0000000000000000 R08: 00007ffd7e9b8950 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000 R13: 0000000000000000 R14: 00000000016a4350 R15: 0000000000000003 INFO: task syz-executor.5:8386 blocked for more than 140 seconds. Not tainted 4.14.209-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.5 D24600 8386 1 0x00000004 Call Trace: context_switch kernel/sched/core.c:2808 [inline] __schedule+0x824/0x1ee0 kernel/sched/core.c:3384 schedule+0x7f/0x1b0 kernel/sched/core.c:3428 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3486 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x519/0x1490 kernel/locking/mutex.c:893 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908 rtnl_lock net/core/rtnetlink.c:72 [inline] rtnetlink_rcv_msg+0x2c0/0x9e0 net/core/rtnetlink.c:4311 netlink_rcv_skb+0x12f/0x3b0 net/netlink/af_netlink.c:2433 rtnetlink_rcv+0x10/0x20 net/core/rtnetlink.c:4328 netlink_unicast_kernel net/netlink/af_netlink.c:1287 [inline] netlink_unicast+0x40b/0x610 net/netlink/af_netlink.c:1313 netlink_sendmsg+0x657/0xc60 net/netlink/af_netlink.c:1878 sock_sendmsg_nosec net/socket.c:646 [inline] sock_sendmsg+0xac/0xf0 net/socket.c:656 SYSC_sendto net/socket.c:1763 [inline] SyS_sendto+0x1e4/0x2c0 net/socket.c:1731 do_syscall_64+0x1c7/0x5b0 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x4178c7 RSP: 002b:00007ffe4061f380 EFLAGS: 00000293 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00000000016a4300 RCX: 00000000004178c7 RDX: 0000000000000020 RSI: 00000000016a4350 RDI: 0000000000000004 RBP: 0000000000000000 R08: 00007ffe4061f390 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000293 R12: 00007ffe4061f3fc R13: 0000000000000010 R14: 00000000016a4350 R15: 0000000000000004 INFO: task syz-executor.4:8387 blocked for more than 140 seconds. Not tainted 4.14.209-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.4 D24920 8387 1 0x00000004 Call Trace: context_switch kernel/sched/core.c:2808 [inline] __schedule+0x824/0x1ee0 kernel/sched/core.c:3384 schedule+0x7f/0x1b0 kernel/sched/core.c:3428 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3486 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x519/0x1490 kernel/locking/mutex.c:893 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908 rtnl_lock net/core/rtnetlink.c:72 [inline] rtnetlink_rcv_msg+0x2c0/0x9e0 net/core/rtnetlink.c:4311 netlink_rcv_skb+0x12f/0x3b0 net/netlink/af_netlink.c:2433 rtnetlink_rcv+0x10/0x20 net/core/rtnetlink.c:4328 netlink_unicast_kernel net/netlink/af_netlink.c:1287 [inline] netlink_unicast+0x40b/0x610 net/netlink/af_netlink.c:1313 netlink_sendmsg+0x657/0xc60 net/netlink/af_netlink.c:1878 sock_sendmsg_nosec net/socket.c:646 [inline] sock_sendmsg+0xac/0xf0 net/socket.c:656 SYSC_sendto net/socket.c:1763 [inline] SyS_sendto+0x1e4/0x2c0 net/socket.c:1731 do_syscall_64+0x1c7/0x5b0 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x4178c7 RSP: 002b:00007ffd225899d0 EFLAGS: 00000293 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00000000016a4300 RCX: 00000000004178c7 RDX: 0000000000000040 RSI: 00000000016a4350 RDI: 0000000000000003 RBP: 0000000000000000 R08: 00007ffd225899e0 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000 R13: 0000000000000000 R14: 00000000016a4350 R15: 0000000000000003 Showing all locks held in the system: 3 locks held by kworker/u4:0/5: #0: ("cfg80211"){+.+.}, at: [] process_one_work+0x681/0x1620 kernel/workqueue.c:2087 #1: ((&rdev->event_work)){+.+.}, at: [] process_one_work+0x6b4/0x1620 kernel/workqueue.c:2091 #2: (rtnl_mutex){+.+.}, at: [] rtnl_lock+0x12/0x20 net/core/rtnetlink.c:72 3 locks held by kworker/1:1/23: #0: ("events"){+.+.}, at: [] process_one_work+0x681/0x1620 kernel/workqueue.c:2087 #1: ((linkwatch_work).work){+.+.}, at: [] process_one_work+0x6b4/0x1620 kernel/workqueue.c:2091 #2: (rtnl_mutex){+.+.}, at: [] rtnl_lock+0x12/0x20 net/core/rtnetlink.c:72 3 locks held by kworker/0:1/24: #0: ("%s"("ipv6_addrconf")){+.+.}, at: [] process_one_work+0x681/0x1620 kernel/workqueue.c:2087 #1: ((&(&ifa->dad_work)->work)){+.+.}, at: [] process_one_work+0x6b4/0x1620 kernel/workqueue.c:2091 #2: (rtnl_mutex){+.+.}, at: [] rtnl_lock+0x12/0x20 net/core/rtnetlink.c:72 1 lock held by khungtaskd/1530: #0: (tasklist_lock){.+.+}, at: [] debug_show_all_locks+0x79/0x218 kernel/locking/lockdep.c:4548 3 locks held by kworker/0:2/3617: #0: ("events"){+.+.}, at: [] process_one_work+0x681/0x1620 kernel/workqueue.c:2087 #1: (cfg80211_disconnect_work){+.+.}, at: [] process_one_work+0x6b4/0x1620 kernel/workqueue.c:2091 #2: (rtnl_mutex){+.+.}, at: [] rtnl_lock+0x12/0x20 net/core/rtnetlink.c:72 3 locks held by kworker/1:2/4304: #0: ("events_power_efficient"){+.+.}, at: [] process_one_work+0x681/0x1620 kernel/workqueue.c:2087 #1: ((reg_check_chans).work){+.+.}, at: [] process_one_work+0x6b4/0x1620 kernel/workqueue.c:2091 #2: (rtnl_mutex){+.+.}, at: [] rtnl_lock+0x12/0x20 net/core/rtnetlink.c:72 3 locks held by kworker/1:4/8199: #0: ("%s"("ipv6_addrconf")){+.+.}, at: [] process_one_work+0x681/0x1620 kernel/workqueue.c:2087 #1: ((&(&ifa->dad_work)->work)){+.+.}, at: [] process_one_work+0x6b4/0x1620 kernel/workqueue.c:2091 #2: (rtnl_mutex){+.+.}, at: [] rtnl_lock+0x12/0x20 net/core/rtnetlink.c:72 1 lock held by syz-executor.3/8379: #0: (rtnl_mutex){+.+.}, at: [] rtnl_lock net/core/rtnetlink.c:72 [inline] #0: (rtnl_mutex){+.+.}, at: [] rtnetlink_rcv_msg+0x2c0/0x9e0 net/core/rtnetlink.c:4311 2 locks held by syz-executor.2/8382: #0: (cb_lock){++++}, at: [] genl_rcv+0x14/0x40 net/netlink/genetlink.c:635 #1: (genl_mutex){+.+.}, at: [] genl_lock net/netlink/genetlink.c:33 [inline] #1: (genl_mutex){+.+.}, at: [] genl_rcv_msg+0x10e/0x140 net/netlink/genetlink.c:623 1 lock held by syz-executor.5/8386: #0: (rtnl_mutex){+.+.}, at: [] rtnl_lock net/core/rtnetlink.c:72 [inline] #0: (rtnl_mutex){+.+.}, at: [] rtnetlink_rcv_msg+0x2c0/0x9e0 net/core/rtnetlink.c:4311 1 lock held by syz-executor.4/8387: #0: (rtnl_mutex){+.+.}, at: [] rtnl_lock net/core/rtnetlink.c:72 [inline] #0: (rtnl_mutex){+.+.}, at: [] rtnetlink_rcv_msg+0x2c0/0x9e0 net/core/rtnetlink.c:4311 1 lock held by syz-executor.0/8388: #0: (rtnl_mutex){+.+.}, at: [] rtnl_lock net/core/rtnetlink.c:72 [inline] #0: (rtnl_mutex){+.+.}, at: [] rtnetlink_rcv_msg+0x2c0/0x9e0 net/core/rtnetlink.c:4311 2 locks held by syz-executor.1/9856: #0: (cb_lock){++++}, at: [] genl_rcv+0x14/0x40 net/netlink/genetlink.c:635 #1: (genl_mutex){+.+.}, at: [] genl_lock net/netlink/genetlink.c:33 [inline] #1: (genl_mutex){+.+.}, at: [] genl_rcv_msg+0x10e/0x140 net/netlink/genetlink.c:623 2 locks held by syz-executor.1/9857: #0: (cb_lock){++++}, at: [] genl_rcv+0x14/0x40 net/netlink/genetlink.c:635 #1: (genl_mutex){+.+.}, at: [] genl_lock net/netlink/genetlink.c:33 [inline] #1: (genl_mutex){+.+.}, at: [] genl_rcv_msg+0x10e/0x140 net/netlink/genetlink.c:623 2 locks held by syz-executor.1/9858: #0: (cb_lock){++++}, at: [] genl_rcv+0x14/0x40 net/netlink/genetlink.c:635 #1: (genl_mutex){+.+.}, at: [] genl_lock net/netlink/genetlink.c:33 [inline] #1: (genl_mutex){+.+.}, at: [] genl_rcv_msg+0x10e/0x140 net/netlink/genetlink.c:623 2 locks held by syz-executor.1/9859: #0: (cb_lock){++++}, at: [] genl_rcv+0x14/0x40 net/netlink/genetlink.c:635 #1: (genl_mutex){+.+.}, at: [] genl_lock net/netlink/genetlink.c:33 [inline] #1: (genl_mutex){+.+.}, at: [] genl_rcv_msg+0x10e/0x140 net/netlink/genetlink.c:623 2 locks held by syz-executor.1/9861: #0: (cb_lock){++++}, at: [] genl_rcv+0x14/0x40 net/netlink/genetlink.c:635 #1: (genl_mutex){+.+.}, at: [] genl_lock net/netlink/genetlink.c:33 [inline] #1: (genl_mutex){+.+.}, at: [] genl_rcv_msg+0x10e/0x140 net/netlink/genetlink.c:623 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1530 Comm: khungtaskd Not tainted 4.14.209-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x14b/0x1f1 lib/dump_stack.c:58 nmi_cpu_backtrace.cold.0+0x3c/0x78 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0xf6/0x11a 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:140 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:195 [inline] watchdog+0x51b/0xa70 kernel/hung_task.c:274 kthread+0x338/0x400 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 9849 Comm: syz-executor.1 Not tainted 4.14.209-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff8880b2cda200 task.stack: ffff88809d998000 RIP: 0010:ieee80211_chanctx_radar_detect+0x1ab/0x340 net/mac80211/util.c:3349 RSP: 0018:ffff88809d99f300 EFLAGS: 00000a02 RAX: 0000000000000000 RBX: ffff88809998d080 RCX: 1ffff110137b1624 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88809998d988 RBP: ffff88809d99f330 R08: 1ffff1101659b550 R09: ffff88809998d080 R10: ffff88809d99f430 R11: 0000000000000000 R12: dffffc0000000000 R13: ffff88809bd8b120 R14: ffff88809bd8b100 R15: 0000000000000000 FS: 00007ff3f1b62700(0000) GS:ffff8880ba600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f8526f9a020 CR3: 00000000b4211000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: ieee80211_check_combinations+0x2e3/0x9b0 net/mac80211/util.c:3408 ieee80211_check_concurrent_iface+0x3a9/0x640 net/mac80211/iface.c:311 ieee80211_runtime_change_iftype net/mac80211/iface.c:1558 [inline] ieee80211_if_change_type+0x230/0x400 net/mac80211/iface.c:1596 ieee80211_change_iface+0x29/0x1e0 net/mac80211/cfg.c:156 rdev_change_virtual_intf net/wireless/rdev-ops.h:69 [inline] cfg80211_change_iface+0x200/0x1160 net/wireless/util.c:1048 nl80211_set_interface+0x443/0x840 net/wireless/nl80211.c:2929 genl_family_rcv_msg+0x57f/0xfe0 net/netlink/genetlink.c:600 genl_rcv_msg+0xa7/0x140 net/netlink/genetlink.c:625 netlink_rcv_skb+0x12f/0x3b0 net/netlink/af_netlink.c:2433 genl_rcv+0x23/0x40 net/netlink/genetlink.c:636 netlink_unicast_kernel net/netlink/af_netlink.c:1287 [inline] netlink_unicast+0x40b/0x610 net/netlink/af_netlink.c:1313 netlink_sendmsg+0x657/0xc60 net/netlink/af_netlink.c:1878 sock_sendmsg_nosec net/socket.c:646 [inline] sock_sendmsg+0xac/0xf0 net/socket.c:656 ___sys_sendmsg+0x625/0x920 net/socket.c:2062 __sys_sendmsg+0xc1/0x140 net/socket.c:2096 SYSC_sendmsg net/socket.c:2107 [inline] SyS_sendmsg+0xd/0x20 net/socket.c:2103 do_syscall_64+0x1c7/0x5b0 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x45de49 RSP: 002b:00007ff3f1b61c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 000000000002bf00 RCX: 000000000045de49 RDX: 0000000000000000 RSI: 0000000020000340 RDI: 0000000000000004 RBP: 000000000118bf60 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118bf2c R13: 00007ffccc9f40ff R14: 00007ff3f1b629c0 R15: 000000000118bf2c Code: 9a 20 f8 ff ff 49 39 d5 0f 84 90 00 00 00 49 bc 00 00 00 00 00 fc ff df 48 8d bb 08 09 00 00 48 89 fa 48 c1 ea 03 42 0f b6 14 22 <84> d2 74 06 0f 8e ff 00 00 00 80 bb 08 09 00 00 00 74 30 48 8d