INFO: task kworker/0:0:6896 blocked for more than 143 seconds. Not tainted 5.9.0-rc8-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/0:0 state:D stack:29480 pid: 6896 ppid: 2 flags:0x00004000 Workqueue: ipv6_addrconf addrconf_verify_work Call Trace: context_switch kernel/sched/core.c:3778 [inline] __schedule+0xec9/0x2280 kernel/sched/core.c:4527 schedule+0xd0/0x2a0 kernel/sched/core.c:4602 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4661 __mutex_lock_common kernel/locking/mutex.c:1033 [inline] __mutex_lock+0x3e2/0x10e0 kernel/locking/mutex.c:1103 addrconf_verify_work+0xa/0x20 net/ipv6/addrconf.c:4568 process_one_work+0x94c/0x1670 kernel/workqueue.c:2269 worker_thread+0x64c/0x1120 kernel/workqueue.c:2415 kthread+0x3b5/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 Showing all locks held in the system: 1 lock held by khungtaskd/1170: #0: ffffffff8a067f40 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:5852 1 lock held by in:imklog/6569: #0: ffff88809477f870 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:930 3 locks held by kworker/0:0/6896: #0: ffff88809ab09138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff88809ab09138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline] #0: ffff88809ab09138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline] #0: ffff88809ab09138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:616 [inline] #0: ffff88809ab09138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:643 [inline] #0: ffff88809ab09138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x82b/0x1670 kernel/workqueue.c:2240 #1: ffffc90006037da8 ((addr_chk_work).work){+.+.}-{0:0}, at: process_one_work+0x85f/0x1670 kernel/workqueue.c:2244 #2: ffffffff8b150988 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_verify_work+0xa/0x20 net/ipv6/addrconf.c:4568 1 lock held by syz-executor300/6926: ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1170 Comm: khungtaskd Not tainted 5.9.0-rc8-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+0x198/0x1fd lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x70/0xb1 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1b3/0x223 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+0xd7d/0x1000 kernel/hung_task.c:295 kthread+0x3b5/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 3913 Comm: systemd-journal Not tainted 5.9.0-rc8-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:unwind_next_frame+0xb35/0x1f90 arch/x86/kernel/unwind_orc.c:476 Code: 0d 00 00 48 8b 40 60 48 89 44 24 60 e9 ac fb ff ff 49 8d 7f 40 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 <0f> 85 b5 0c 00 00 4c 89 c0 49 8b 57 40 48 be 00 00 00 00 00 fc ff RSP: 0018:ffffc900054bf920 EFLAGS: 00000246 RAX: dffffc0000000000 RBX: 1ffff92000a97f2c RCX: ffffffff8bc434b7 RDX: 1ffff92000a97f51 RSI: 0000000000000001 RDI: ffffc900054bfa88 RBP: 0000000000000001 R08: ffffffff8bc434b2 R09: ffffffff8bc434b6 R10: 000000000007601f R11: 000000000000aad7 R12: ffffc900054bfa90 R13: ffffc900054bfa7d R14: ffffc900054bfa98 R15: ffffc900054bfa48 FS: 00007f0858cb58c0(0000) GS:ffff8880ae500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f0856056000 CR3: 0000000093abc000 CR4: 00000000001506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __unwind_start+0x517/0x800 arch/x86/kernel/unwind_orc.c:702 unwind_start arch/x86/include/asm/unwind.h:60 [inline] arch_stack_walk+0x5e/0xf0 arch/x86/kernel/stacktrace.c:24 stack_trace_save+0x8c/0xc0 kernel/stacktrace.c:123 kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48 kasan_set_track mm/kasan/common.c:56 [inline] __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:461 slab_post_alloc_hook mm/slab.h:518 [inline] slab_alloc mm/slab.c:3316 [inline] kmem_cache_alloc+0x13a/0x3f0 mm/slab.c:3486 getname_flags.part.0+0x50/0x4f0 fs/namei.c:138 getname_flags+0x9a/0xe0 include/linux/audit.h:320 getname fs/namei.c:209 [inline] user_path_create fs/namei.c:3524 [inline] do_mkdirat+0x8d/0x2d0 fs/namei.c:3664 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7f0857f71687 Code: 00 b8 ff ff ff ff c3 0f 1f 40 00 48 8b 05 09 d8 2b 00 64 c7 00 5f 00 00 00 b8 ff ff ff ff c3 0f 1f 40 00 b8 53 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d e1 d7 2b 00 f7 d8 64 89 01 48 RSP: 002b:00007ffd28545128 EFLAGS: 00000293 ORIG_RAX: 0000000000000053 RAX: ffffffffffffffda RBX: 00007ffd28548040 RCX: 00007f0857f71687 RDX: 00007f08589e2a00 RSI: 00000000000001ed RDI: 000055b31d2148a0 RBP: 00007ffd28545160 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000069 R11: 0000000000000293 R12: 0000000000000000 R13: 0000000000000000 R14: 00007ffd28548040 R15: 00007ffd28545650