INFO: task kworker/u4:9:21989 blocked for more than 140 seconds. Not tainted 4.19.211-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/u4:9 D26280 21989 2 0x80000000 Workqueue: netns cleanup_net FAT-fs (loop4): bogus number of reserved sectors Call Trace: context_switch kernel/sched/core.c:2828 [inline] __schedule+0x887/0x2040 kernel/sched/core.c:3517 FAT-fs (loop4): Can't find a valid FAT filesystem schedule+0x8d/0x1b0 kernel/sched/core.c:3561 schedule_timeout+0x92d/0xfe0 kernel/time/timer.c:1794 FAT-fs (loop4): bogus number of reserved sectors do_wait_for_common kernel/sched/completion.c:83 [inline] __wait_for_common kernel/sched/completion.c:104 [inline] wait_for_common+0x29c/0x470 kernel/sched/completion.c:115 FAT-fs (loop4): Can't find a valid FAT filesystem flush_workqueue+0x40b/0x13e0 kernel/workqueue.c:2713 flush_scheduled_work include/linux/workqueue.h:599 [inline] tipc_exit_net+0x38/0x60 net/tipc/core.c:100 FAT-fs (loop4): bogus number of reserved sectors FAT-fs (loop4): Can't find a valid FAT filesystem ops_exit_list+0xa5/0x150 net/core/net_namespace.c:153 cleanup_net+0x3b4/0x8b0 net/core/net_namespace.c:554 process_one_work+0x864/0x1570 kernel/workqueue.c:2153 worker_thread+0x64c/0x1130 kernel/workqueue.c:2296 kthread+0x33f/0x460 kernel/kthread.c:259 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 netlink: 16160 bytes leftover after parsing attributes in process `syz-executor.5'. Showing all locks held in the system: 1 lock held by khungtaskd/1570: #0: 00000000cb37a21e (rcu_read_lock){....}, at: debug_show_all_locks+0x53/0x265 kernel/locking/lockdep.c:4441 2 locks held by kworker/1:2/3510: #0: 00000000a8e6ab40 ((wq_completion)"events"){+.+.}, at: process_one_work+0x767/0x1570 kernel/workqueue.c:2124 #1: 00000000f45eb786 ((work_completion)(&m->rq)){+.+.}, at: process_one_work+0x79c/0x1570 kernel/workqueue.c:2128 1 lock held by systemd-udevd/4701: 1 lock held by in:imklog/7800: #0: 000000007a07a05f (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x26f/0x310 fs/file.c:767 sg_write: data in/out 8156/536871360 bytes for SCSI command 0xd2-- guessing data in; program syz-executor.2 not setting count and/or reply_len properly 2 locks held by kworker/1:1/8127: #0: 00000000a909cc44 ((wq_completion)"rcu_gp"){+.+.}, at: process_one_work+0x767/0x1570 kernel/workqueue.c:2124 #1: 000000008818eda7 ((work_completion)(&rew.rew_work)){+.+.}, at: process_one_work+0x79c/0x1570 kernel/workqueue.c:2128 1 lock held by syz-executor.4/8152: #0: 0000000074275fad (rcu_preempt_state.exp_mutex){+.+.}, at: exp_funnel_lock kernel/rcu/tree_exp.h:297 [inline] #0: 0000000074275fad (rcu_preempt_state.exp_mutex){+.+.}, at: _synchronize_rcu_expedited+0x4dc/0x6f0 kernel/rcu/tree_exp.h:667 sg_write: data in/out 8156/2147479506 bytes for SCSI command 0xd2-- guessing data in; program syz-executor.2 not setting count and/or reply_len properly 3 locks held by kworker/u4:9/21989: #0: 000000006668cf17 ((wq_completion)"%s""netns"){+.+.}, at: process_one_work+0x767/0x1570 kernel/workqueue.c:2124 #1: 000000007155b50a (net_cleanup_work){+.+.}, at: process_one_work+0x79c/0x1570 kernel/workqueue.c:2128 #2: 00000000da4e002b (pernet_ops_rwsem){++++}, at: cleanup_net+0xa8/0x8b0 net/core/net_namespace.c:521 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1570 Comm: khungtaskd Not tainted 4.19.211-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/12/2023 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1fc/0x2ef lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x63/0xa2 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1a6/0x1f0 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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 4693 Comm: systemd-journal Not tainted 4.19.211-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/12/2023 RIP: 0010:__lock_acquire+0x82/0x3ff0 kernel/locking/lockdep.c:3275 Code: 25 c0 df 01 00 48 89 04 24 48 8d 84 24 98 00 00 00 48 c1 e8 03 48 89 44 24 08 48 01 d0 c7 00 f1 f1 f1 f1 c7 40 04 00 f2 f2 f2 40 08 00 00 00 f2 c7 40 0c f2 f2 f2 f2 c7 40 18 f3 f3 f3 f3 65 RSP: 0018:ffff8880a0e27ad8 EFLAGS: 00000082 RAX: ffffed10141c4f6e RBX: 0000000000000000 RCX: 0000000000000000 RDX: dffffc0000000000 RSI: 0000000000000000 RDI: ffff88813be79b18 RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000001 R10: 0000000000000007 R11: 0000000000000000 R12: 0000000000000001 R13: ffff8880a0e1a5c0 R14: ffff88813be79b18 R15: 0000000000000001 FS: 00007f85c5a208c0(0000) GS:ffff8880ba000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f85c334e000 CR3: 00000000a100f000 CR4: 00000000003406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire+0x170/0x3c0 kernel/locking/lockdep.c:3908 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:144 spin_lock include/linux/spinlock.h:329 [inline] cache_grow_end+0x46/0x170 mm/slab.c:2737 cache_alloc_refill+0x2f8/0x340 mm/slab.c:3058 ____cache_alloc mm/slab.c:3132 [inline] __do_cache_alloc mm/slab.c:3354 [inline] slab_alloc mm/slab.c:3389 [inline] kmem_cache_alloc+0x346/0x370 mm/slab.c:3557 getname_flags+0xce/0x590 fs/namei.c:140 user_path_at_empty+0x2a/0x50 fs/namei.c:2609 user_path_at include/linux/namei.h:57 [inline] do_faccessat+0x248/0x7a0 fs/open.c:397 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7f85c4cdb9c7 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:00007fffc341b968 EFLAGS: 00000246 ORIG_RAX: 0000000000000015 RAX: ffffffffffffffda RBX: 00007fffc341e990 RCX: 00007f85c4cdb9c7 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00005638f52fe9a3 RBP: 00007fffc341bab0 R08: 00005638f52f43e5 R09: 0000000000000018 R10: 0000000000000069 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00005638f58c68a0 R15: 00007fffc341bfa0