INFO: task kworker/0:1:7 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/0:1 state:D stack:28456 pid: 7 ppid: 2 flags:0x00004000 Workqueue: ipv6_addrconf addrconf_verify_work Call Trace: context_switch kernel/sched/core.c:4327 [inline] __schedule+0x90c/0x21a0 kernel/sched/core.c:5078 schedule+0xcf/0x270 kernel/sched/core.c:5157 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:5216 __mutex_lock_common kernel/locking/mutex.c:1033 [inline] __mutex_lock+0x81a/0x1110 kernel/locking/mutex.c:1103 addrconf_verify_work+0xa/0x20 net/ipv6/addrconf.c:4570 process_one_work+0x98d/0x15f0 kernel/workqueue.c:2275 worker_thread+0x64c/0x1120 kernel/workqueue.c:2421 kthread+0x3b1/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296 Showing all locks held in the system: 3 locks held by kworker/0:1/7: #0: ffff888147a0f938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff888147a0f938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline] #0: ffff888147a0f938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline] #0: ffff888147a0f938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:616 [inline] #0: ffff888147a0f938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:643 [inline] #0: ffff888147a0f938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x871/0x15f0 kernel/workqueue.c:2246 #1: ffffc90000cdfda8 ((addr_chk_work).work){+.+.}-{0:0}, at: process_one_work+0x8a5/0x15f0 kernel/workqueue.c:2250 #2: ffffffff8d45bce8 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_verify_work+0xa/0x20 net/ipv6/addrconf.c:4570 1 lock held by khungtaskd/1647: #0: ffffffff8bd73da0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6259 1 lock held by in:imklog/8202: #0: ffff8880147483f0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:947 1 lock held by syz-executor879/8444: ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1647 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+0x107/0x163 lib/dump_stack.c:120 nmi_cpu_backtrace.cold+0x44/0xd7 lib/nmi_backtrace.c:105 nmi_trigger_cpumask_backtrace+0x1b3/0x230 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+0xd43/0xfa0 kernel/hung_task.c:294 kthread+0x3b1/0x4a0 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: 4856 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:hlock_class kernel/locking/lockdep.c:193 [inline] RIP: 0010:check_wait_context kernel/locking/lockdep.c:4507 [inline] RIP: 0010:__lock_acquire+0x454/0x54f0 kernel/locking/lockdep.c:4782 Code: b8 00 00 00 00 00 fc ff df 48 8b 54 24 28 45 0f b7 ad b8 00 00 00 48 c1 ea 03 0f b6 04 02 84 c0 74 08 3c 03 0f 8e e4 10 00 00 <45> 0f b7 7c 24 20 66 41 81 e7 ff 1f 45 0f b7 ff be 08 00 00 00 4c RSP: 0018:ffffc900090bf9c0 EFLAGS: 00000046 RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffffff81587143 RDX: 1ffff1100286813d RSI: 0000000000000008 RDI: ffffffff8f875c78 RBP: ffff888014340040 R08: 0000000000000000 R09: ffffffff8f8757a7 R10: fffffbfff1f0eaf4 R11: 0000000000000000 R12: ffff8880143409c8 R13: 0000000000000002 R14: ffffffff8fe6f190 R15: 0000000000040000 FS: 00007ff9a9df78c0(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ff9a71d9000 CR3: 00000000148a4000 CR4: 00000000001506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire kernel/locking/lockdep.c:5442 [inline] lock_acquire+0x1a8/0x720 kernel/locking/lockdep.c:5407 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x39/0x50 kernel/locking/spinlock.c:159 __debug_check_no_obj_freed lib/debugobjects.c:975 [inline] debug_check_no_obj_freed+0xc7/0x420 lib/debugobjects.c:1018 kmem_cache_free+0x13f/0x1c0 mm/slab.c:3696 putname+0xe1/0x120 fs/namei.c:259 filename_lookup+0x3b1/0x560 fs/namei.c:2379 user_path_at include/linux/namei.h:59 [inline] do_faccessat+0x129/0x820 fs/open.c:423 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7ff9a90b29c7 Code: 83 c4 08 48 3d 01 f0 ff ff 73 01 c3 48 8b 0d c8 d4 2b 00 f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 b8 15 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d a1 d4 2b 00 f7 d8 64 89 01 48 RSP: 002b:00007ffd74167788 EFLAGS: 00000246 ORIG_RAX: 0000000000000015 RAX: ffffffffffffffda RBX: 00007ffd7416a7b0 RCX: 00007ff9a90b29c7 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000055e9da3679a3 RBP: 00007ffd741678d0 R08: 000055e9da35d3e5 R09: 0000000000000018 R10: 0000000000000069 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 000055e9db90a8c0 R15: 00007ffd74167dc0