INFO: task syz-executor312:3588 blocked for more than 143 seconds. Not tainted 6.1.28-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor312 state:D stack:23800 pid:3588 ppid:3586 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5241 [inline] __schedule+0x132c/0x4330 kernel/sched/core.c:6554 schedule+0xbf/0x180 kernel/sched/core.c:6630 wb_wait_for_completion+0x162/0x290 fs/fs-writeback.c:191 sync_inodes_sb+0x293/0xab0 fs/fs-writeback.c:2717 sync_filesystem+0x16b/0x220 fs/sync.c:64 generic_shutdown_super+0x6b/0x340 fs/super.c:474 kill_block_super+0x7a/0xe0 fs/super.c:1450 deactivate_locked_super+0xa0/0x110 fs/super.c:332 cleanup_mnt+0x490/0x520 fs/namespace.c:1186 task_work_run+0x246/0x300 kernel/task_work.c:179 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop+0xd9/0x100 kernel/entry/common.c:171 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:204 __syscall_exit_to_user_mode_work kernel/entry/common.c:286 [inline] syscall_exit_to_user_mode+0x60/0x270 kernel/entry/common.c:297 do_syscall_64+0x49/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f7c48401de7 RSP: 002b:00007ffd87afe568 EFLAGS: 00000202 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f7c48401de7 RDX: 00007ffd87afe629 RSI: 000000000000000a RDI: 00007ffd87afe620 RBP: 00007ffd87afe620 R08: 00000000ffffffff R09: 00007ffd87afe400 R10: 0000555555f08653 R11: 0000000000000202 R12: 00007ffd87aff690 R13: 0000555555f085f0 R14: 00007ffd87afe590 R15: 0000000000000001 Showing all locks held in the system: 4 locks held by kworker/u4:1/11: #0: ffff8880146e5138 ( (wq_completion)writeback ){+.+.}-{0:0} , at: process_one_work+0x77a/0x11f0 #1: ffffc90000107d20 ( (work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x7bd/0x11f0 kernel/workqueue.c:2264 #2: ffff88807b126650 (sb_internal#2){.+.+}-{0:0}, at: xfs_bmapi_convert_delalloc+0x263/0x12d0 fs/xfs/libxfs/xfs_bmap.c:4521 #3: ffff888073d288d8 (&xfs_nondir_ilock_class){++++}-{3:3}, at: rcu_lock_acquire+0x0/0x30 1 lock held by rcu_tasks_kthre/12: #0: ffffffff8cf274b0 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3} , at: rcu_tasks_one_gp+0x29/0xd20 kernel/rcu/tasks.h:510 1 lock held by rcu_tasks_trace/13: #0: ffffffff8cf27cb0 ( rcu_tasks_trace.tasks_gp_mutex ){+.+.}-{3:3} , at: rcu_tasks_one_gp+0x29/0xd20 kernel/rcu/tasks.h:510 1 lock held by khungtaskd/28: #0: ffffffff8cf272e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 5 locks held by kworker/0:3/2963: 2 locks held by getty/3301: #0: ffff88814b3cf098 ( &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+0x6a7/0x1db0 drivers/tty/n_tty.c:2177 2 locks held by syz-executor312/3588: #0: ffff88807b1260e0 ( &type->s_umount_key#42){+.+.}-{3:3}, at: deactivate_super+0xa9/0xe0 fs/super.c:362 #1: ffff888143fec7d0 ( &bdi->wb_switch_rwsem ){+.+.}-{3:3} , at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:362 [inline] , at: sync_inodes_sb+0x274/0xab0 fs/fs-writeback.c:2715 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 28 Comm: khungtaskd Not tainted 6.1.28-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/28/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106 nmi_cpu_backtrace+0x4e1/0x560 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x1b0/0x3f0 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+0xf18/0xf60 kernel/hung_task.c:377 kthread+0x26e/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: 11 Comm: kworker/u4:1 Not tainted 6.1.28-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/28/2023 Workqueue: writeback wb_workfn (flush-7:0) RIP: 0010:check_kcov_mode kernel/kcov.c:175 [inline] RIP: 0010:write_comp_data kernel/kcov.c:236 [inline] RIP: 0010:__sanitizer_cov_trace_switch+0x7c/0xe0 kernel/kcov.c:340 Code: c2 49 39 d2 74 71 4c 8b 74 d6 10 65 8b 05 c4 9a 78 7e a9 00 01 ff 00 74 11 a9 00 01 00 00 74 de 41 83 bb 1c 16 00 00 00 74 d4 <41> 8b 83 f8 15 00 00 83 f8 03 75 c8 49 8b 8b 00 16 00 00 45 8b bb RSP: 0018:ffffc90000106398 EFLAGS: 00000246 RAX: 0000000080000001 RBX: 0000000000000009 RCX: 000000000000008b RDX: 0000000000000001 RSI: ffffffff8e3c8fa0 RDI: 0000000000000009 RBP: ffffc900001064b0 R08: 0000000000000001 R09: ffffffff8a7c1fb4 R10: 0000000000000002 R11: ffff88813fe7bb80 R12: ffff0a0000000509 R13: 1ffff92000020c88 R14: 0000000000000002 R15: ffffffff8aec93c5 FS: 0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005653a4540600 CR3: 000000000cc8e000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: format_decode+0x104/0x1f10 lib/vsprintf.c:2513 vsnprintf+0x14d/0x1c70 lib/vsprintf.c:2752 sprintf+0xd6/0x120 lib/vsprintf.c:3004 print_time kernel/printk/printk.c:1274 [inline] info_print_prefix+0x167/0x300 kernel/printk/printk.c:1300 record_print_text kernel/printk/printk.c:1349 [inline] console_emit_next_record+0x6e2/0xda0 kernel/printk/printk.c:2714 console_unlock+0x278/0x6e0 kernel/printk/printk.c:2860 vprintk_emit+0xd1/0x1f0 kernel/printk/printk.c:2268 _printk+0xd1/0x111 kernel/printk/printk.c:2289 __xfs_printk fs/xfs/xfs_message.c:24 [inline] xfs_printk_level+0x1c6/0x310 fs/xfs/xfs_message.c:44 xfs_discard_folio+0x2b1/0x7b0 fs/xfs/xfs_aops.c:469 iomap_writepage_map fs/iomap/buffered-io.c:1394 [inline] iomap_do_writepage+0x2432/0x3110 fs/iomap/buffered-io.c:1523 write_cache_pages+0x92e/0x15c0 mm/page-writeback.c:2360 iomap_writepages+0x64/0x240 fs/iomap/buffered-io.c:1540 xfs_vm_writepages+0x127/0x180 fs/xfs/xfs_aops.c:500 do_writepages+0x3a2/0x670 mm/page-writeback.c:2469 __writeback_single_inode+0x15d/0x11e0 fs/fs-writeback.c:1590 writeback_sb_inodes+0xc21/0x1ac0 fs/fs-writeback.c:1881 wb_writeback+0x49d/0xe10 fs/fs-writeback.c:2055 wb_do_writeback fs/fs-writeback.c:2198 [inline] wb_workfn+0x427/0x1020 fs/fs-writeback.c:2238 process_one_work+0x8aa/0x11f0 kernel/workqueue.c:2289 worker_thread+0xa5f/0x1210 kernel/workqueue.c:2436 kthread+0x26e/0x300 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.771 msecs