syzbot

INFO: task kworker/1:2:3645 blocked for more than 143 seconds.
      Not tainted 5.11.0-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/1:2     state:D stack:26432 pid: 3645 ppid:     2 flags:0x00004000
Workqueue: ipv6_addrconf addrconf_verify_work
Call Trace:
 context_switch kernel/sched/core.c:4327 [inline]
 __schedule+0x999/0xe70 kernel/sched/core.c:5078
 schedule+0x14b/0x200 kernel/sched/core.c:5157
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:5216
 __mutex_lock_common+0x124f/0x2f00 kernel/locking/mutex.c:1033
 __mutex_lock kernel/locking/mutex.c:1103 [inline]
 mutex_lock_nested+0x1a/0x20 kernel/locking/mutex.c:1118
 addrconf_verify_work+0xa/0x20 net/ipv6/addrconf.c:4570
 process_one_work+0x789/0xfc0 kernel/workqueue.c:2275
 worker_thread+0xac1/0x1300 kernel/workqueue.c:2421
 kthread+0x39a/0x3c0 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296

Showing all locks held in the system:
1 lock held by khungtaskd/1645:
 #0: ffffffff8c711680 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 arch/x86/pci/mmconfig_64.c:151
3 locks held by kworker/1:2/3645:
 #0: ffff888147206d38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x6f4/0xfc0 kernel/workqueue.c:2248
 #1: ffffc900024d7d78 ((addr_chk_work).work){+.+.}-{0:0}, at: process_one_work+0x733/0xfc0 kernel/workqueue.c:2250
 #2: ffffffff8d6ee888 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_verify_work+0xa/0x20 net/ipv6/addrconf.c:4570
1 lock held by in:imklog/8108:
 #0: ffff8880192f0370 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x24e/0x2f0 fs/file.c:947
2 locks held by syz-executor117/8421:

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

NMI backtrace for cpu 0
CPU: 0 PID: 1645 Comm: khungtaskd Not tainted 5.11.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:79 [inline]
 dump_stack+0x137/0x1be lib/dump_stack.c:120
 nmi_cpu_backtrace+0x16c/0x190 lib/nmi_backtrace.c:105
 nmi_trigger_cpumask_backtrace+0x191/0x2f0 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+0xce9/0xd30 kernel/hung_task.c:294
 kthread+0x39a/0x3c0 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 4854 Comm: systemd-journal Not tainted 5.11.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:get_current arch/x86/include/asm/current.h:15 [inline]
RIP: 0010:write_comp_data kernel/kcov.c:217 [inline]
RIP: 0010:__sanitizer_cov_trace_const_cmp4+0x4/0xa0 kernel/kcov.c:284
Code: c1 e0 03 48 83 c8 18 48 89 34 01 4c 89 44 f9 18 49 ff c2 4c 89 11 c3 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 4c 8b 04 24 <65> 48 8b 14 25 80 ef 01 00 65 8b 05 b8 0a 8a 7e a9 00 01 ff 00 74
RSP: 0018:ffffc90000edfe18 EFLAGS: 00000246
RAX: 0000000000000001 RBX: 0000000000000001 RCX: ffff888012425340
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffff888024ce2218 R08: ffffffff81cc95ad R09: fffff520001dbfc3
R10: fffff520001dbfc3 R11: 0000000000000000 R12: dffffc0000000000
R13: ffff888024ce2220 R14: 0000000000000015 R15: ffff888024ce21c0
FS:  00007f6e2f3518c0(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f6e2c71f018 CR3: 0000000024d92000 CR4: 00000000001506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 __put_unused_fd+0x4d/0x1c0 fs/file.c:539
 put_unused_fd+0x58/0x70 fs/file.c:549
 do_sys_openat2+0xd2/0x380 fs/open.c:1174
 do_sys_open fs/open.c:1188 [inline]
 __do_sys_open fs/open.c:1196 [inline]
 __se_sys_open fs/open.c:1192 [inline]
 __x64_sys_open+0x1af/0x1e0 fs/open.c:1192
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7f6e2e8e0840
Code: 73 01 c3 48 8b 0d 68 77 20 00 f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 83 3d 89 bb 20 00 00 75 10 b8 02 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 1e f6 ff ff 48 89 04 24
RSP: 002b:00007ffff1215078 EFLAGS: 00000246 ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 00007ffff1215380 RCX: 00007f6e2e8e0840
RDX: 00000000000001a0 RSI: 0000000000080042 RDI: 000055e8e98e67a0
RBP: 000000000000000d R08: 000000000000ffc0 R09: 00000000ffffffff
R10: 0000000000000069 R11: 0000000000000246 R12: 00000000ffffffff
R13: 000055e8e98d9040 R14: 00007ffff1215340 R15: 000055e8e98e6840