INFO: task syz-executor.4:25584 blocked for more than 143 seconds. Not tainted 5.12.0-rc4-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.4 state:D stack:28440 pid:25584 ppid: 18097 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:4322 [inline] __schedule+0x911/0x21b0 kernel/sched/core.c:5073 schedule+0xcf/0x270 kernel/sched/core.c:5152 rwsem_down_write_slowpath+0x7e5/0x1200 kernel/locking/rwsem.c:1106 __down_write_common kernel/locking/rwsem.c:1261 [inline] __down_write_common kernel/locking/rwsem.c:1258 [inline] __down_write kernel/locking/rwsem.c:1270 [inline] down_write+0x137/0x150 kernel/locking/rwsem.c:1407 unregister_netdevice_notifier+0x1e/0x170 net/core/dev.c:1949 raw_release+0x58/0x8a0 net/can/raw.c:352 __sock_release+0xcd/0x280 net/socket.c:599 sock_close+0x18/0x20 net/socket.c:1258 __fput+0x288/0x920 fs/file_table.c:280 task_work_run+0xdd/0x1a0 kernel/task_work.c:140 exit_task_work include/linux/task_work.h:30 [inline] do_exit+0xbfc/0x2a60 kernel/exit.c:825 do_group_exit+0x125/0x310 kernel/exit.c:922 get_signal+0x42c/0x2100 kernel/signal.c:2777 arch_do_signal_or_restart+0x2a8/0x1eb0 arch/x86/kernel/signal.c:789 handle_signal_work kernel/entry/common.c:147 [inline] exit_to_user_mode_loop kernel/entry/common.c:171 [inline] exit_to_user_mode_prepare+0x148/0x250 kernel/entry/common.c:208 __syscall_exit_to_user_mode_work kernel/entry/common.c:290 [inline] syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:301 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x466459 RSP: 002b:00007f05fda22188 EFLAGS: 00000246 ORIG_RAX: 0000000000000029 RAX: 0000000000000004 RBX: 000000000056c008 RCX: 0000000000466459 RDX: 0000000000000001 RSI: 0000000000000003 RDI: 000000000000001d RBP: 00000000004bf9fb R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056c008 R13: 00007fff201209af R14: 00007f05fda22300 R15: 0000000000022000 Showing all locks held in the system: 1 lock held by khungtaskd/1613: #0: ffffffff8bf74360 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6327 1 lock held by in:imklog/8109: #0: ffff88801ca16ff0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:961 3 locks held by kworker/u4:6/9864: 3 locks held by kworker/u4:8/15695: #0: ffff8880116d3138 ((wq_completion)netns){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff8880116d3138 ((wq_completion)netns){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline] #0: ffff8880116d3138 ((wq_completion)netns){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline] #0: ffff8880116d3138 ((wq_completion)netns){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:616 [inline] #0: ffff8880116d3138 ((wq_completion)netns){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:643 [inline] #0: ffff8880116d3138 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x871/0x1600 kernel/workqueue.c:2246 #1: ffffc900027ffda8 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x8a5/0x1600 kernel/workqueue.c:2250 #2: ffffffff8d65cfd0 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x9b/0xb10 net/core/net_namespace.c:557 2 locks held by syz-executor.4/25584: #0: ffff88806b533150 (&sb->s_type->i_mutex_key#13){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:775 [inline] #0: ffff88806b533150 (&sb->s_type->i_mutex_key#13){+.+.}-{3:3}, at: __sock_release+0x86/0x280 net/socket.c:598 #1: ffffffff8d65cfd0 (pernet_ops_rwsem){++++}-{3:3}, at: unregister_netdevice_notifier+0x1e/0x170 net/core/dev.c:1949 1 lock held by syz-executor.4/25758: #0: ffffffff8d65cfd0 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x2fa/0x760 net/core/net_namespace.c:470 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1613 Comm: khungtaskd Not tainted 5.12.0-rc4-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+0x141/0x1d7 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+0xd48/0xfb0 kernel/hung_task.c:294 kthread+0x3b1/0x4a0 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: 8110 Comm: rs:main Q:Reg Not tainted 5.12.0-rc4-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__ext4_journal_stop+0x2/0x1f0 fs/ext4/ext4_jbd2.c:110 Code: fd ff ff e8 60 1a b5 ff e9 67 fe ff ff 48 c7 c7 40 35 b2 8d e8 4f 1a b5 ff e9 ca fe ff ff 66 2e 0f 1f 84 00 00 00 00 00 41 57 <41> 56 41 89 f6 41 55 49 89 fd 41 54 55 48 89 d5 53 e8 e8 0b 71 ff RSP: 0018:ffffc9000b87f930 EFLAGS: 00000282 RAX: 0000000000000000 RBX: ffff888022148000 RCX: 0000000000000000 RDX: 0000000000000002 RSI: 000000000000173e RDI: ffffffff897f5140 RBP: ffff88802e9f0338 R08: 0000000000000000 R09: ffff888029cf4063 R10: ffffffff820a54ee R11: 0000000000000000 R12: 0000000000000002 R13: ffffffff820b6eb0 R14: 0000000000000000 R15: 00000000000dd000 FS: 00007faa5bfa6700(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007faa4c005920 CR3: 000000001bc22000 CR4: 00000000001506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: ext4_dirty_inode+0xe8/0x110 fs/ext4/inode.c:5950 __mark_inode_dirty+0x6e3/0x10f0 fs/fs-writeback.c:2274 mark_inode_dirty include/linux/fs.h:2267 [inline] generic_write_end+0x316/0x4f0 fs/buffer.c:2203 ext4_da_write_end+0x20f/0xb50 fs/ext4/inode.c:3112 generic_perform_write+0x2c0/0x4f0 mm/filemap.c:3586 ext4_buffered_write_iter+0x244/0x4d0 fs/ext4/file.c:269 ext4_file_write_iter+0x423/0x14e0 fs/ext4/file.c:663 call_write_iter include/linux/fs.h:1977 [inline] new_sync_write+0x426/0x650 fs/read_write.c:518 vfs_write+0x796/0xa30 fs/read_write.c:605 ksys_write+0x12d/0x250 fs/read_write.c:658 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7faa5e9ea1cd Code: c2 20 00 00 75 10 b8 01 00 00 00 0f 05 48 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 ae fc ff ff 48 89 04 24 b8 01 00 00 00 0f 05 <48> 8b 3c 24 48 89 c2 e8 f7 fc ff ff 48 89 d0 48 83 c4 08 48 3d 01 RSP: 002b:00007faa5bfa5590 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007faa4c0269f0 RCX: 00007faa5e9ea1cd RDX: 00000000000004bb RSI: 00007faa4c0269f0 RDI: 0000000000000007 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 00007faa4c026770 R13: 00007faa5bfa55b0 R14: 0000560c2caa5440 R15: 00000000000004bb