INFO: task syz-executor.5:3673 blocked for more than 143 seconds. Not tainted 6.1.0-rc5-syzkaller-00008-ge01d50cbd6ee #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.5 state:D stack:17712 pid:3673 ppid:1 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5191 [inline] __schedule+0x8c9/0xd70 kernel/sched/core.c:6503 schedule+0xcb/0x190 kernel/sched/core.c:6579 wb_wait_for_completion+0x155/0x280 fs/fs-writeback.c:191 sync_inodes_sb+0x283/0xaa0 fs/fs-writeback.c:2706 sync_filesystem+0x16b/0x220 fs/sync.c:64 generic_shutdown_super+0x6b/0x310 fs/super.c:474 kill_block_super+0x79/0xd0 fs/super.c:1428 deactivate_locked_super+0xa7/0xf0 fs/super.c:332 cleanup_mnt+0x494/0x520 fs/namespace.c:1186 task_work_run+0x243/0x300 kernel/task_work.c:179 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop+0x124/0x150 kernel/entry/common.c:171 exit_to_user_mode_prepare+0xb2/0x140 kernel/entry/common.c:203 __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline] syscall_exit_to_user_mode+0x26/0x60 kernel/entry/common.c:296 do_syscall_64+0x49/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f2a28e8caa7 RSP: 002b:00007ffc17b72d38 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f2a28e8caa7 RDX: 00007ffc17b72e0b RSI: 000000000000000a RDI: 00007ffc17b72e00 RBP: 00007ffc17b72e00 R08: 00000000ffffffff R09: 00007ffc17b72bd0 R10: 00005555563fc8b3 R11: 0000000000000246 R12: 00007f2a28ee5b2e R13: 00007ffc17b73ec0 R14: 00005555563fc810 R15: 00007ffc17b73f00 Showing all locks held in the system: 2 locks held by kworker/u4:0/9: #0: ffff88814586c138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x7f2/0xdb0 #1: ffffc900000e7d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x831/0xdb0 kernel/workqueue.c:2264 1 lock held by rcu_tasks_kthre/12: #0: ffffffff8d327330 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x30/0xd00 kernel/rcu/tasks.h:507 1 lock held by rcu_tasks_trace/13: #0: ffffffff8d327b30 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x30/0xd00 kernel/rcu/tasks.h:507 1 lock held by khungtaskd/28: #0: ffffffff8d327160 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 3 locks held by kworker/u4:3/46: 2 locks held by getty/3305: #0: ffff88802890a098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244 #1: ffffc900031262f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x53b/0x1650 drivers/tty/n_tty.c:2177 2 locks held by syz-executor.5/3673: #0: ffff88807ab560e0 (&type->s_umount_key#87){++++}-{3:3}, at: deactivate_super+0x96/0xd0 fs/super.c:362 #1: ffff88801f8427d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:362 [inline] #1: ffff88801f8427d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x264/0xaa0 fs/fs-writeback.c:2704 1 lock held by syz-executor.0/12249: #0: ffff88807ab560e0 (&type->s_umount_key#87){++++}-{3:3}, at: iterate_supers+0xb0/0x1f0 fs/super.c:722 1 lock held by syz-executor.0/12254: #0: ffff88807ab560e0 (&type->s_umount_key#87){++++}-{3:3}, at: iterate_supers+0xb0/0x1f0 fs/super.c:722 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 28 Comm: khungtaskd Not tainted 6.1.0-rc5-syzkaller-00008-ge01d50cbd6ee #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1b1/0x28e lib/dump_stack.c:106 nmi_cpu_backtrace+0x46f/0x4f0 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x1ba/0x420 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline] watchdog+0xcf5/0xd40 kernel/hung_task.c:377 kthread+0x266/0x300 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 46 Comm: kworker/u4:3 Not tainted 6.1.0-rc5-syzkaller-00008-ge01d50cbd6ee #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 Workqueue: bat_events batadv_nc_worker RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:29 [inline] RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:70 [inline] RIP: 0010:check_preemption_disabled+0x50/0x110 lib/smp_processor_id.c:19 Code: 75 a9 ff ff ff 7f 74 22 65 48 8b 04 25 28 00 00 00 48 3b 44 24 08 0f 85 c4 00 00 00 89 d8 48 83 c4 10 5b 41 5c 41 5e 41 5f c3 <9c> 8f 04 24 f7 04 24 00 02 00 00 74 d1 49 89 f6 49 89 ff 65 4c 8b RSP: 0018:ffffc90000b779e8 EFLAGS: 00000046 RAX: 0000000080000000 RBX: 0000000000000000 RCX: 0000000080000001 RDX: 0000000000000000 RSI: ffffffff8aedbf80 RDI: ffffffff8b4d49a0 RBP: ffffc90000b77b50 R08: dffffc0000000000 R09: fffffbfff1d2f29e R10: fffffbfff1d2f29e R11: 1ffffffff1d2f29d R12: dffffc0000000000 R13: 1ffff9200016ef48 R14: ffffc90000b77a60 R15: 0000000000000246 FS: 0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000c00d49da60 CR3: 000000000d08e000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lockdep_recursion_inc kernel/locking/lockdep.c:461 [inline] lock_acquire+0x149/0x3c0 kernel/locking/lockdep.c:5667 rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:304 rcu_read_lock include/linux/rcupdate.h:738 [inline] batadv_nc_process_nc_paths+0xc1/0x370 net/batman-adv/network-coding.c:687 batadv_nc_worker+0x3de/0x5b0 net/batman-adv/network-coding.c:728 process_one_work+0x877/0xdb0 kernel/workqueue.c:2289 worker_thread+0xb14/0x1330 kernel/workqueue.c:2436 kthread+0x266/0x300 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306