INFO: task syz.7.1161:10132 blocked for more than 141 seconds. Not tainted 6.12.0-rc4-syzkaller-00819-gb62607870b29 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.7.1161 state:D stack:23808 pid:10132 tgid:10132 ppid:9148 flags:0x00000000 Call Trace: context_switch kernel/sched/core.c:5328 [inline] __schedule+0x18af/0x4bd0 kernel/sched/core.c:6690 __schedule_loop kernel/sched/core.c:6767 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6782 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6839 __mutex_lock_common kernel/locking/mutex.c:684 [inline] __mutex_lock+0x6a7/0xd70 kernel/locking/mutex.c:752 pipe_release+0x48/0x320 fs/pipe.c:727 __fput+0x23f/0x880 fs/file_table.c:431 task_work_run+0x24f/0x310 kernel/task_work.c:239 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop kernel/entry/common.c:114 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x168/0x370 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fbbf657e719 RSP: 002b:00007fffe6268ef8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00007fbbf6737a80 RCX: 00007fbbf657e719 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007fbbf6737a80 R08: 0000000000000006 R09: 00007fffe62691ef R10: 00000000003ffbd0 R11: 0000000000000246 R12: 0000000000051c0b R13: 00007fffe6269000 R14: 0000000000000032 R15: ffffffffffffffff Showing all locks held in the system: 1 lock held by khungtaskd/30: #0: ffffffff8e937e20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff8e937e20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8e937e20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6720 2 locks held by getty/5596: #0: ffff8880314e10a0 (&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 1 lock held by syz-executor/5827: 4 locks held by syz-executor/9141: 2 locks held by syz-executor/9144: 1 lock held by syz-executor/9148: 1 lock held by syz-executor/9151: 4 locks held by syz-executor/9209: #0: ffff8880b863ead8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:598 #1: ffff8880b8628948 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x41d/0x7a0 kernel/sched/psi.c:987 #2: ffff88805cea0758 (&sb->s_type->i_lock_key#9){+.+.}-{2:2}, at: spin_trylock include/linux/spinlock.h:361 [inline] #2: ffff88805cea0758 (&sb->s_type->i_lock_key#9){+.+.}-{2:2}, at: lock_for_kill+0x85/0x210 fs/dcache.c:660 #3: ffffffff9a6902c0 (&obj_hash[i].lock){-.-.}-{2:2}, at: debug_object_assert_init+0x164/0x440 lib/debugobjects.c:897 2 locks held by syz.7.1161/10132: #0: ffffffff8fcd41e8 (rtnl_mutex){+.+.}-{3:3}, at: ppp_release+0x87/0x1f0 drivers/net/ppp/ppp_generic.c:408 #1: ffffffff8e93d3b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:329 [inline] #1: ffffffff8e93d3b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x451/0x830 kernel/rcu/tree_exp.h:976 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.12.0-rc4-syzkaller-00819-gb62607870b29 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 3523 Comm: kworker/u8:8 Not tainted 6.12.0-rc4-syzkaller-00819-gb62607870b29 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:sched_idle_rq kernel/sched/fair.c:6906 [inline] RIP: 0010:dequeue_entities+0xb84/0xfa0 kernel/sched/fair.c:7169 Code: 74 20 89 c3 48 8b 44 24 58 42 0f b6 04 20 84 c0 0f 85 5e 02 00 00 48 8b 44 24 40 83 38 00 89 d8 74 7f 84 c0 0f 84 8d 00 00 00 <43> 0f b6 44 25 00 84 c0 0f 85 5e 02 00 00 8b 5d 00 48 8b 44 24 50 RSP: 0018:ffffc9000ca97780 EFLAGS: 00000002 RAX: 0000000000000001 RBX: 0000000000000001 RCX: dffffc0000000000 RDX: 000000000016e360 RSI: 0000000000000001 RDI: ffff8880b863ebc8 RBP: ffff8880b863eb00 R08: ffffffff81447d53 R09: 1ffffffff203a4b5 R10: dffffc0000000000 R11: fffffbfff203a4b6 R12: dffffc0000000000 R13: 1ffff110170c7d60 R14: ffff8880b863eac0 R15: ffff8880328e9e00 FS: 0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000056356d337f50 CR3: 000000000e734000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: dequeue_task_fair+0xdc/0x1e0 kernel/sched/fair.c:7196 block_task kernel/sched/core.c:2090 [inline] __schedule+0x5e8/0x4bd0 kernel/sched/core.c:6638 __schedule_loop kernel/sched/core.c:6767 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6782 toggle_allocation_gate+0x171/0x260 mm/kfence/core.c:851 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