syzbot

IPv6: ADDRCONF(NETDEV_UP): wlan0: link is not ready
IPv6: ADDRCONF(NETDEV_CHANGE): wlan0: link becomes ready
INFO: task kworker/0:1:14 blocked for more than 140 seconds.
      Not tainted 4.19.157-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
kworker/0:1     D26552    14      2 0x80000000
Workqueue: events linkwatch_event
Call Trace:
 context_switch kernel/sched/core.c:2828 [inline]
 __schedule+0x887/0x2040 kernel/sched/core.c:3517
 schedule+0x8d/0x1b0 kernel/sched/core.c:3561
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3619
 __mutex_lock_common kernel/locking/mutex.c:1002 [inline]
 __mutex_lock+0x647/0x1260 kernel/locking/mutex.c:1072
 linkwatch_event+0xb/0x60 net/core/link_watch.c:236
 process_one_work+0x864/0x1570 kernel/workqueue.c:2155
 worker_thread+0x64c/0x1130 kernel/workqueue.c:2298
 kthread+0x33f/0x460 kernel/kthread.c:259
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415
INFO: task kworker/0:0:8130 blocked for more than 140 seconds.
      Not tainted 4.19.157-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
kworker/0:0     D27416  8130      2 0x80000000
Workqueue: ipv6_addrconf addrconf_dad_work
Call Trace:
 context_switch kernel/sched/core.c:2828 [inline]
 __schedule+0x887/0x2040 kernel/sched/core.c:3517
 schedule+0x8d/0x1b0 kernel/sched/core.c:3561
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3619
 __mutex_lock_common kernel/locking/mutex.c:1002 [inline]
 __mutex_lock+0x647/0x1260 kernel/locking/mutex.c:1072
 addrconf_dad_work+0x9c/0x10a0 net/ipv6/addrconf.c:3988
 process_one_work+0x864/0x1570 kernel/workqueue.c:2155
 worker_thread+0x64c/0x1130 kernel/workqueue.c:2298
 kthread+0x33f/0x460 kernel/kthread.c:259
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415

Showing all locks held in the system:
3 locks held by kworker/0:1/14:
 #0: 00000000e55d9845 ((wq_completion)"events"){+.+.}, at: process_one_work+0x767/0x1570 kernel/workqueue.c:2126
 #1: 00000000489dd410 ((linkwatch_work).work){+.+.}, at: process_one_work+0x79c/0x1570 kernel/workqueue.c:2130
 #2: 00000000fb70e3fd (rtnl_mutex){+.+.}, at: linkwatch_event+0xb/0x60 net/core/link_watch.c:236
3 locks held by kworker/1:1/25:
 #0: 00000000cf9cbaaa ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: process_one_work+0x767/0x1570 kernel/workqueue.c:2126
 #1: 0000000005dfb04d ((addr_chk_work).work){+.+.}, at: process_one_work+0x79c/0x1570 kernel/workqueue.c:2130
 #2: 00000000fb70e3fd (rtnl_mutex){+.+.}, at: addrconf_verify_work+0xa/0x20 net/ipv6/addrconf.c:4475
1 lock held by khungtaskd/1566:
 #0: 0000000035d44def (rcu_read_lock){....}, at: debug_show_all_locks+0x53/0x265 kernel/locking/lockdep.c:4440
1 lock held by in:imklog/7779:
 #0: 00000000a612ab87 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x26f/0x310 fs/file.c:767
3 locks held by kworker/0:0/8130:
 #0: 00000000cf9cbaaa ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: process_one_work+0x767/0x1570 kernel/workqueue.c:2126
 #1: 000000007c79bb18 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}, at: process_one_work+0x79c/0x1570 kernel/workqueue.c:2130
 #2: 00000000fb70e3fd (rtnl_mutex){+.+.}, at: addrconf_dad_work+0x9c/0x10a0 net/ipv6/addrconf.c:3988
4 locks held by syz-executor805/8150:

=============================================

NMI backtrace for cpu 0
CPU: 0 PID: 1566 Comm: khungtaskd Not tainted 4.19.157-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+0x1fc/0x2fe lib/dump_stack.c:118
 nmi_cpu_backtrace.cold+0x63/0xa2 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x1a6/0x1eb lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:203 [inline]
 watchdog+0x991/0xe60 kernel/hung_task.c:287
 kthread+0x33f/0x460 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: 8150 Comm: syz-executor805 Not tainted 4.19.157-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:ieee80211_chanctx_radar_detect+0x258/0x390 net/mac80211/util.c:3492
Code: 00 48 89 f8 48 c1 e8 03 42 0f b6 04 30 84 c0 74 08 3c 03 0f 8e 00 01 00 00 8b 8b 00 10 00 00 b8 01 00 00 00 48 d3 e0 41 09 c4 <e8> 53 5f a1 f9 48 8d bb f8 07 00 00 48 89 f8 48 c1 e8 03 42 80 3c
RSP: 0018:ffff88809642f3a0 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffff8880abd40ec0 RCX: ffffffff87c36fce
RDX: 0000000000000000 RSI: ffff8880b07d6600 RDI: 0000000000000001
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000
R13: ffff8880ab2c7920 R14: dffffc0000000000 R15: 0000000000000000
FS:  0000000000b7c880(0000) GS:ffff8880ba100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005588cea94f00 CR3: 00000000a573f000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 ieee80211_check_combinations+0x3b8/0x810 net/mac80211/util.c:3552
 ieee80211_check_concurrent_iface+0x46d/0x650 net/mac80211/iface.c:312
 ieee80211_runtime_change_iftype net/mac80211/iface.c:1541 [inline]
 ieee80211_if_change_type+0x27b/0x5f0 net/mac80211/iface.c:1579
 ieee80211_change_iface+0x26/0x220 net/mac80211/cfg.c:157
 rdev_change_virtual_intf net/wireless/rdev-ops.h:69 [inline]
 cfg80211_change_iface+0x2e1/0x1530 net/wireless/util.c:936
 nl80211_set_interface+0x661/0x830 net/wireless/nl80211.c:3205
 genl_family_rcv_msg+0x642/0xc40 net/netlink/genetlink.c:602
 genl_rcv_msg+0xbf/0x160 net/netlink/genetlink.c:627
 netlink_rcv_skb+0x160/0x440 net/netlink/af_netlink.c:2455
 genl_rcv+0x24/0x40 net/netlink/genetlink.c:638
 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
 netlink_unicast+0x4d5/0x690 net/netlink/af_netlink.c:1344
 netlink_sendmsg+0x6bb/0xc40 net/netlink/af_netlink.c:1909
 sock_sendmsg_nosec net/socket.c:622 [inline]
 sock_sendmsg+0xc3/0x120 net/socket.c:632
 ___sys_sendmsg+0x7bb/0x8e0 net/socket.c:2115
 __sys_sendmsg net/socket.c:2153 [inline]
 __do_sys_sendmsg net/socket.c:2162 [inline]
 __se_sys_sendmsg net/socket.c:2160 [inline]
 __x64_sys_sendmsg+0x132/0x220 net/socket.c:2160
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x442449
Code: e8 4c ff 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 db 06 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007ffc13fd0128 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000442449
RDX: 0000000000000000 RSI: 0000000020000340 RDI: 0000000000000004
RBP: 000000306e616c77 R08: 00000000004002e0 R09: 00000000004002e0
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000402fb0
R13: 0000000000403040 R14: 0000000000000000 R15: 0000000000000000
INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.239 msecs