INFO: task kworker/u8:3:52 blocked for more than 143 seconds. Not tainted 6.11.0-syzkaller-08481-g88264981f208-dirty #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u8:3 state:D stack:20920 pid:52 tgid:52 ppid:2 flags:0x00004000 Workqueue: writeback wb_workfn (flush-7:0) Call Trace: context_switch kernel/sched/core.c:5315 [inline] __schedule+0x1843/0x4ae0 kernel/sched/core.c:6674 __schedule_loop kernel/sched/core.c:6751 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6766 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6823 __mutex_lock_common kernel/locking/mutex.c:684 [inline] __mutex_lock+0x6a7/0xd70 kernel/locking/mutex.c:752 exfat_write_inode+0x69/0x120 fs/exfat/inode.c:105 write_inode fs/fs-writeback.c:1503 [inline] __writeback_single_inode+0x711/0x10d0 fs/fs-writeback.c:1723 writeback_sb_inodes+0x80c/0x1370 fs/fs-writeback.c:1954 __writeback_inodes_wb+0x11b/0x260 fs/fs-writeback.c:2025 wb_writeback+0x42f/0xbd0 fs/fs-writeback.c:2136 wb_check_background_flush fs/fs-writeback.c:2206 [inline] wb_do_writeback fs/fs-writeback.c:2294 [inline] wb_workfn+0xc58/0x1090 fs/fs-writeback.c:2321 process_one_work kernel/workqueue.c:3229 [inline] process_scheduled_works+0xa63/0x1850 kernel/workqueue.c:3310 worker_thread+0x870/0xd30 kernel/workqueue.c:3391 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Showing all locks held in the system: 4 locks held by kworker/1:0/25: 1 lock held by khungtaskd/30: #0: ffffffff8e937ee0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff8e937ee0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8e937ee0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6701 4 locks held by kworker/u8:3/52: #0: ffff88801d69a948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff88801d69a948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310 #1: ffffc90000bd7d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc90000bd7d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310 #2: ffff88806a0c80e0 (&type->s_umount_key#52){.+.+}-{3:3}, at: super_trylock_shared+0x22/0xf0 fs/super.c:562 #3: ffff8880320ae0e0 (&sbi->s_lock){+.+.}-{3:3}, at: exfat_write_inode+0x69/0x120 fs/exfat/inode.c:105 2 locks held by getty/4967: #0: ffff88802ee4f0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90002f062f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6a6/0x1e00 drivers/tty/n_tty.c:2211 3 locks held by syz-executor/5823: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.11.0-syzkaller-08481-g88264981f208-dirty #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 nmi_cpu_backtrace+0x49c/0x4d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:223 [inline] watchdog+0xff4/0x1040 kernel/hung_task.c:379 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 25 Comm: kworker/1:0 Not tainted 6.11.0-syzkaller-08481-g88264981f208-dirty #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024 Workqueue: events_power_efficient gc_worker RIP: 0010:validate_chain+0x3c/0x5920 kernel/locking/lockdep.c:3857 Code: 83 e4 e0 48 81 ec c0 02 00 00 49 89 ce 89 54 24 58 48 89 bc 24 80 00 00 00 65 48 8b 04 25 28 00 00 00 48 89 84 24 a0 02 00 00 <49> bc 00 00 00 00 00 fc ff df 48 c7 84 24 00 01 00 00 b3 8a b5 41 RSP: 0018:ffffc900001f7440 EFLAGS: 00000082 RAX: 438d1bde2932f600 RBX: ffffffff93c242d0 RCX: cf88bb94f0f89771 RDX: 0000000000000000 RSI: ffff88801d2fa958 RDI: ffff88801d2f9e00 RBP: ffffc900001f7740 R08: ffffffff94223857 R09: 1ffffffff284470a R10: dffffc0000000000 R11: fffffbfff284470b R12: 0000000000000000 R13: ffff88801d2fa8d8 R14: cf88bb94f0f89771 R15: ffff88801d2fa978 FS: 0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000056370143e600 CR3: 00000000303d6000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __lock_acquire+0x1384/0x2050 kernel/locking/lockdep.c:5199 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5822 seqcount_lockdep_reader_access+0x13f/0x220 include/linux/seqlock.h:73 nf_conntrack_get_ht include/net/netfilter/nf_conntrack.h:345 [inline] gc_worker+0x316/0x1530 net/netfilter/nf_conntrack_core.c:1488 process_one_work kernel/workqueue.c:3229 [inline] process_scheduled_works+0xa63/0x1850 kernel/workqueue.c:3310 worker_thread+0x870/0xd30 kernel/workqueue.c:3391 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244