INFO: task kworker/u4:2:36 blocked for more than 143 seconds. Not tainted 5.9.0-rc6-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u4:2 state:D stack:24104 pid: 36 ppid: 2 flags:0x00004000 Workqueue: netns cleanup_net 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 fib6_rules_net_exit+0xe/0x50 net/ipv6/fib6_rules.c:496 ops_exit_list+0xb0/0x160 net/core/net_namespace.c:186 cleanup_net+0x4ea/0xa00 net/core/net_namespace.c:603 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: 4 locks held by kworker/u4:2/36: #0: ffff8880a9797138 ((wq_completion)netns){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff8880a9797138 ((wq_completion)netns){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline] #0: ffff8880a9797138 ((wq_completion)netns){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline] #0: ffff8880a9797138 ((wq_completion)netns){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:616 [inline] #0: ffff8880a9797138 ((wq_completion)netns){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:643 [inline] #0: ffff8880a9797138 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x82b/0x1670 kernel/workqueue.c:2240 #1: ffffc90000e97da8 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x85f/0x1670 kernel/workqueue.c:2244 #2: ffffffff8b13c030 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x9b/0xa00 net/core/net_namespace.c:565 #3: ffffffff8b14d828 (rtnl_mutex){+.+.}-{3:3}, at: fib6_rules_net_exit+0xe/0x50 net/ipv6/fib6_rules.c:496 1 lock held by khungtaskd/1175: #0: ffffffff8a067f00 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:5852 1 lock held by in:imklog/6617: #0: ffff888093b14430 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:930 3 locks held by kworker/0:5/8236: #0: ffff8880aa063d38 ((wq_completion)events){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff8880aa063d38 ((wq_completion)events){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline] #0: ffff8880aa063d38 ((wq_completion)events){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline] #0: ffff8880aa063d38 ((wq_completion)events){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:616 [inline] #0: ffff8880aa063d38 ((wq_completion)events){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:643 [inline] #0: ffff8880aa063d38 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x82b/0x1670 kernel/workqueue.c:2240 #1: ffffc9001600fda8 (deferred_process_work){+.+.}-{0:0}, at: process_one_work+0x85f/0x1670 kernel/workqueue.c:2244 #2: ffffffff8b14d828 (rtnl_mutex){+.+.}-{3:3}, at: switchdev_deferred_process_work+0xa/0x20 net/switchdev/switchdev.c:74 3 locks held by kworker/u4:6/9437: 3 locks held by kworker/1:9/12304: #0: ffff888214cf6938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff888214cf6938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline] #0: ffff888214cf6938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline] #0: ffff888214cf6938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:616 [inline] #0: ffff888214cf6938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:643 [inline] #0: ffff888214cf6938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x82b/0x1670 kernel/workqueue.c:2240 #1: ffffc90006a27da8 ((addr_chk_work).work){+.+.}-{0:0}, at: process_one_work+0x85f/0x1670 kernel/workqueue.c:2244 #2: ffffffff8b14d828 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_verify_work+0xa/0x20 net/ipv6/addrconf.c:4568 2 locks held by syz-executor.0/3609: ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1175 Comm: khungtaskd Not tainted 5.9.0-rc6-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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 3918 Comm: systemd-journal Not tainted 5.9.0-rc6-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:debug_lockdep_rcu_enabled+0x23/0x30 kernel/rcu/update.c:291 Code: cc cc cc cc cc cc cc 8b 05 7a 18 33 03 85 c0 74 21 8b 05 ec 49 33 03 85 c0 74 17 65 48 8b 04 25 c0 fe 01 00 8b 80 e4 08 00 00 <85> c0 0f 94 c0 0f b6 c0 c3 cc cc cc cc 55 53 48 c7 c3 00 6c 03 00 RSP: 0018:ffffc90005517900 EFLAGS: 00000202 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff815c000f RDX: fffffbfff16b2d12 RSI: 0000000000000008 RDI: ffffffff8b596888 RBP: 1ffff92000aa2f25 R08: 0000000000000000 R09: ffffffff8b59688f R10: fffffbfff16b2d11 R11: 0000000000000000 R12: 0000000000000001 R13: ffffffff8a067f00 R14: ffffffff81822b59 R15: 0000000000000008 FS: 00007f4eacdd38c0(0000) GS:ffff8880ae400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f4eaa2d6010 CR3: 00000000a96ed000 CR4: 00000000001506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rcu_read_lock_held_common kernel/rcu/update.c:115 [inline] rcu_read_lock_sched_held+0xd/0xb0 kernel/rcu/update.c:134 trace_lock_release include/trace/events/lock.h:58 [inline] lock_release+0x6a1/0x8f0 kernel/locking/lockdep.c:5040 rcu_lock_release include/linux/rcupdate.h:246 [inline] rcu_read_unlock include/linux/rcupdate.h:688 [inline] is_bpf_text_address+0xcb/0x160 kernel/bpf/core.c:706 kernel_text_address kernel/extable.c:151 [inline] kernel_text_address+0xbd/0xf0 kernel/extable.c:120 __kernel_text_address+0x9/0x30 kernel/extable.c:105 unwind_get_return_address arch/x86/kernel/unwind_orc.c:317 [inline] unwind_get_return_address+0x51/0x90 arch/x86/kernel/unwind_orc.c:312 arch_stack_walk+0x97/0xf0 arch/x86/kernel/stacktrace.c:26 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 __do_kmalloc mm/slab.c:3655 [inline] __kmalloc+0x1b0/0x360 mm/slab.c:3664 kmalloc include/linux/slab.h:559 [inline] kzalloc include/linux/slab.h:666 [inline] lsm_cred_alloc security/security.c:532 [inline] security_prepare_creds+0x10e/0x190 security/security.c:1631 prepare_creds+0x4bd/0x6c0 kernel/cred.c:285 access_override_creds fs/open.c:353 [inline] do_faccessat+0x3d7/0x820 fs/open.c:417 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7f4eac08f9c7 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:00007ffdb724a368 EFLAGS: 00000246 ORIG_RAX: 0000000000000015 RAX: ffffffffffffffda RBX: 00007ffdb724d390 RCX: 00007f4eac08f9c7 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000055be349e79a3 RBP: 00007ffdb724a4b0 R08: 000055be349dd3e5 R09: 0000000000000018 R10: 0000000000000069 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 000055be360eb8a0 R15: 00007ffdb724a9a0