INFO: task segctord:5966 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. segctord D30088 5966 2 0x80000000 Call Trace: context_switch kernel/sched/core.c:2828 [inline] __schedule+0x887/0x2040 kernel/sched/core.c:3517 schedule+0x8d/0x1b0 kernel/sched/core.c:3561 __rwsem_down_write_failed_common kernel/locking/rwsem-xadd.c:589 [inline] rwsem_down_write_failed+0x3aa/0x760 kernel/locking/rwsem-xadd.c:618 call_rwsem_down_write_failed+0x13/0x20 arch/x86/lib/rwsem.S:117 __down_write arch/x86/include/asm/rwsem.h:142 [inline] down_write+0x4f/0x90 kernel/locking/rwsem.c:72 nilfs_transaction_lock+0x1fb/0x8b0 fs/nilfs2/segment.c:362 nilfs_segctor_thread_construct fs/nilfs2/segment.c:2479 [inline] nilfs_segctor_thread+0x3c0/0xf50 fs/nilfs2/segment.c:2563 kthread+0x33f/0x460 kernel/kthread.c:259 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 Showing all locks held in the system: 1 lock held by khungtaskd/1570: #0: 00000000540b82f2 (rcu_read_lock){....}, at: debug_show_all_locks+0x53/0x265 kernel/locking/lockdep.c:4441 1 lock held by systemd-udevd/4700: 1 lock held by in:imklog/7798: #0: 000000000fbc53e5 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x26f/0x310 fs/file.c:767 3 locks held by kworker/u4:5/8800: 3 locks held by kworker/0:3/9306: #0: 00000000bd508b58 ((wq_completion)"events"){+.+.}, at: process_one_work+0x767/0x1570 kernel/workqueue.c:2124 #1: 00000000a4d4eef8 ((work_completion)(&map->work)){+.+.}, at: process_one_work+0x79c/0x1570 kernel/workqueue.c:2128 #2: 0000000082a1786a (rcu_preempt_state.exp_mutex){+.+.}, at: exp_funnel_lock kernel/rcu/tree_exp.h:329 [inline] #2: 0000000082a1786a (rcu_preempt_state.exp_mutex){+.+.}, at: _synchronize_rcu_expedited+0x256/0x6f0 kernel/rcu/tree_exp.h:667 2 locks held by agetty/21160: #0: 000000007aa61fc5 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:272 #1: 000000007a6a8179 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x217/0x1950 drivers/tty/n_tty.c:2154 6 locks held by syz-executor.4/5958: 1 lock held by segctord/5966: #0: 000000000b18230a (&nilfs->ns_segctor_sem){++++}, at: nilfs_transaction_lock+0x1fb/0x8b0 fs/nilfs2/segment.c:362 2 locks held by syz-executor.3/19739: #0: 00000000c8341ceb (&evdev->mutex){+.+.}, at: evdev_close_device drivers/input/evdev.c:433 [inline] #0: 00000000c8341ceb (&evdev->mutex){+.+.}, at: evdev_release+0x26f/0x3e0 drivers/input/evdev.c:478 #1: 000000006c726a2f (&dev->mutex#2){+.+.}, at: input_close_device+0x42/0x150 drivers/input/input.c:658 1 lock held by syz-executor.2/19776: 4 locks held by syz-executor.0/19785: 3 locks held by syz-executor.0/19787: #0: 000000004448c2f3 (sb_writers#3){.+.+}, at: sb_start_write include/linux/fs.h:1579 [inline] #0: 000000004448c2f3 (sb_writers#3){.+.+}, at: mnt_want_write_file+0x63/0x1d0 fs/namespace.c:418 #1: 000000001734b31b (&sb->s_type->i_mutex_key#10){++++}, at: inode_lock include/linux/fs.h:748 [inline] #1: 000000001734b31b (&sb->s_type->i_mutex_key#10){++++}, at: lock_two_nondirectories+0xec/0x110 fs/inode.c:1015 #2: 0000000097ef390a (&sb->s_type->i_mutex_key#10/4){+.+.}, at: inode_lock_nested include/linux/fs.h:783 [inline] #2: 0000000097ef390a (&sb->s_type->i_mutex_key#10/4){+.+.}, at: lock_two_nondirectories+0xd1/0x110 fs/inode.c:1017 2 locks held by syz-executor.0/19788: #0: 000000004448c2f3 (sb_writers#3){.+.+}, at: sb_start_write include/linux/fs.h:1579 [inline] #0: 000000004448c2f3 (sb_writers#3){.+.+}, at: mnt_want_write_file+0x63/0x1d0 fs/namespace.c:418 #1: 0000000097ef390a (&sb->s_type->i_mutex_key#10){++++}, at: inode_lock include/linux/fs.h:748 [inline] #1: 0000000097ef390a (&sb->s_type->i_mutex_key#10){++++}, at: ext4_ioctl+0x2a95/0x3eb0 fs/ext4/ioctl.c:1162 2 locks held by syz-executor.0/19789: #0: 000000004448c2f3 (sb_writers#3){.+.+}, at: sb_start_write include/linux/fs.h:1579 [inline] #0: 000000004448c2f3 (sb_writers#3){.+.+}, at: mnt_want_write+0x3a/0xb0 fs/namespace.c:360 #1: 00000000540b82f2 (rcu_read_lock){....}, at: trace_sched_stat_runtime include/trace/events/sched.h:428 [inline] #1: 00000000540b82f2 (rcu_read_lock){....}, at: update_curr+0x2c3/0x870 kernel/sched/fair.c:857 1 lock held by syz-executor.1/19823: ============================================= 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 10/26/2022 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: 9306 Comm: kworker/0:3 Not tainted 4.19.211-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 Workqueue: events_power_efficient fb_flashcursor RIP: 0010:slow_down_io arch/x86/include/asm/paravirt.h:268 [inline] RIP: 0010:outb_p arch/x86/include/asm/io.h:333 [inline] RIP: 0010:vga_io_w include/video/vga.h:209 [inline] RIP: 0010:setsr drivers/video/fbdev/vga16fb.c:161 [inline] RIP: 0010:vga_imageblit_expand drivers/video/fbdev/vga16fb.c:1163 [inline] RIP: 0010:vga16fb_imageblit+0x8e0/0x2260 drivers/video/fbdev/vga16fb.c:1260 Code: 89 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 80 3c 02 00 0f 85 51 19 00 00 ff 15 eb 06 53 06 b8 0f 00 00 00 ba cf 03 00 00 ee <48> c7 c2 10 82 f1 89 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 80 RSP: 0018:ffff88808c5b7a50 EFLAGS: 00000246 RAX: 000000000000000f RBX: ffffffff8128f470 RCX: ffffffff839e79cc RDX: 00000000000003cf RSI: ffffffff839e79da RDI: 0000000000000005 RBP: ffff8880b063fd04 R08: ffff888238cbc58f R09: 0000000000000000 R10: 0000000000000005 R11: 0000000000000000 R12: ffff888238cb8e08 R13: ffff888238cbc580 R14: ffff8880b063fd20 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8880ba000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f3d9ef4d000 CR3: 000000009af56000 CR4: 00000000003406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: soft_cursor+0x514/0xa30 drivers/video/fbdev/core/softcursor.c:74 bit_cursor+0x1126/0x1740 drivers/video/fbdev/core/bitblit.c:377 fb_flashcursor+0x38c/0x430 drivers/video/fbdev/core/fbcon.c:379 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