INFO: task khugepaged:34 blocked for more than 145 seconds. Not tainted 6.4.0-rc6-syzkaller-00037-gb6dad5178cea #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:khugepaged state:D stack:28168 pid:34 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5343 [inline] __schedule+0xc9a/0x5880 kernel/sched/core.c:6669 schedule+0xde/0x1a0 kernel/sched/core.c:6745 schedule_timeout+0x276/0x2b0 kernel/time/timer.c:2143 do_wait_for_common kernel/sched/completion.c:85 [inline] __wait_for_common+0x1ce/0x5c0 kernel/sched/completion.c:106 __flush_work+0x595/0xb60 kernel/workqueue.c:3189 __lru_add_drain_all+0x1bf/0x6a0 mm/swap.c:897 khugepaged_do_scan mm/khugepaged.c:2599 [inline] khugepaged+0x105/0x1740 mm/khugepaged.c:2668 kthread+0x344/0x440 kernel/kthread.c:379 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 Showing all locks held in the system: 2 locks held by kworker/u4:1/12: #0: ffff888012479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff888012479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline] #0: ffff888012479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1324 [inline] #0: ffff888012479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:643 [inline] #0: ffff888012479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:670 [inline] #0: ffff888012479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x883/0x15e0 kernel/workqueue.c:2376 #1: ffff8880b9828848 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x2de/0x950 kernel/sched/psi.c:996 1 lock held by rcu_tasks_kthre/13: #0: ffffffff8c7984b0 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x31/0xd80 kernel/rcu/tasks.h:518 1 lock held by rcu_tasks_trace/14: #0: ffffffff8c7981b0 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x31/0xd80 kernel/rcu/tasks.h:518 1 lock held by khungtaskd/28: #0: ffffffff8c7990c0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x340 kernel/locking/lockdep.c:6559 1 lock held by khugepaged/34: #0: ffffffff8c89a608 (lock#3){+.+.}-{3:3}, at: __lru_add_drain_all+0x62/0x6a0 mm/swap.c:852 2 locks held by kworker/u4:3/46: #0: ffff8880b983c5d8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2f/0x120 kernel/sched/core.c:558 #1: ffffc90000b77db0 ((work_completion)(&sdata->work)){+.+.}-{0:0}, at: psi_task_switch+0x2de/0x950 kernel/sched/psi.c:996 2 locks held by getty/4767: #0: ffff88802d152098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x26/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc900015902f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xef4/0x13e0 drivers/tty/n_tty.c:2176 3 locks held by kworker/1:3/5072: 1 lock held by syz-executor.2/27625: 2 locks held by syz-executor.5/27630: 1 lock held by syz-executor.4/27632: 1 lock held by syz-executor.3/27635: 1 lock held by syz-executor.0/27637: 2 locks held by syz-executor.1/27639: ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 28 Comm: khungtaskd Not tainted 6.4.0-rc6-syzkaller-00037-gb6dad5178cea #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/27/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd9/0x150 lib/dump_stack.c:106 nmi_cpu_backtrace+0x29c/0x350 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x2a4/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline] watchdog+0xe16/0x1090 kernel/hung_task.c:379 kthread+0x344/0x440 kernel/kthread.c:379 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 27639 Comm: syz-executor.1 Not tainted 6.4.0-rc6-syzkaller-00037-gb6dad5178cea #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/27/2023 RIP: 0010:unwind_next_frame+0x3bf/0x1e30 arch/x86/kernel/unwind_orc.c:467 Code: c7 c2 84 aa fb 8e 4c 89 f9 48 c7 c6 84 aa fb 8e 48 81 ea 28 de 85 8e 48 c7 c7 28 de 85 8e 48 c1 fa 02 e8 d4 f5 ff ff 48 89 c1 <48> 85 c9 0f 84 a0 02 00 00 4c 8d 79 05 48 b8 00 00 00 00 00 fc ff RSP: 0018:ffffc9000354eef8 EFLAGS: 00000286 RAX: ffffffff8f0eb140 RBX: 0000000000000001 RCX: ffffffff8f0eb140 RDX: 0000000000000000 RSI: ffffffff8f0eb11c RDI: ffffffff8e928d38 RBP: ffffc9000354efb0 R08: ffffffff8f0eb11c R09: ffffc9000354f190 R10: ffffc9000354ef68 R11: 0000000000094001 R12: ffffc9000354efb8 R13: ffffc9000354ef68 R14: ffffc9000354ef9d R15: ffffffff81e01e8e FS: 00007f5d2db20700(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f5d2daff718 CR3: 0000000043695000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: arch_stack_walk+0x81/0xf0 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x90/0xc0 kernel/stacktrace.c:122 save_stack+0x151/0x1e0 mm/page_owner.c:128 __set_page_owner+0x1f/0x60 mm/page_owner.c:192 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x2db/0x350 mm/page_alloc.c:1731 prep_new_page mm/page_alloc.c:1738 [inline] get_page_from_freelist+0xf41/0x2c00 mm/page_alloc.c:3502 __alloc_pages+0x1cb/0x4a0 mm/page_alloc.c:4768 alloc_pages+0x1aa/0x270 mm/mempolicy.c:2279 __get_free_pages+0xc/0x40 mm/page_alloc.c:4818 kasan_populate_vmalloc_pte mm/kasan/shadow.c:323 [inline] kasan_populate_vmalloc_pte+0x2e/0x180 mm/kasan/shadow.c:314 apply_to_pte_range mm/memory.c:2584 [inline] apply_to_pmd_range mm/memory.c:2628 [inline] apply_to_pud_range mm/memory.c:2664 [inline] apply_to_p4d_range mm/memory.c:2700 [inline] __apply_to_page_range+0x68c/0x1030 mm/memory.c:2734 alloc_vmap_area+0x500/0x1e00 mm/vmalloc.c:1642 __get_vm_area_node+0x145/0x3f0 mm/vmalloc.c:2551 __vmalloc_node_range+0x252/0x14a0 mm/vmalloc.c:3217 vmalloc_user+0x6b/0x80 mm/vmalloc.c:3411 vb2_vmalloc_alloc+0x121/0x3f0 drivers/media/common/videobuf2/videobuf2-vmalloc.c:48 __vb2_buf_mem_alloc drivers/media/common/videobuf2/videobuf2-core.c:233 [inline] __vb2_queue_alloc+0x60c/0x1270 drivers/media/common/videobuf2/videobuf2-core.c:444 vb2_core_create_bufs+0x5bd/0xb10 drivers/media/common/videobuf2/videobuf2-core.c:962 vb2_create_bufs+0x454/0x800 drivers/media/common/videobuf2/videobuf2-v4l2.c:794 v4l_create_bufs drivers/media/v4l2-core/v4l2-ioctl.c:2141 [inline] v4l_create_bufs+0xb6/0x160 drivers/media/v4l2-core/v4l2-ioctl.c:2128 __video_do_ioctl+0xba6/0xf20 drivers/media/v4l2-core/v4l2-ioctl.c:3044 video_usercopy+0x4bf/0x14c0 drivers/media/v4l2-core/v4l2-ioctl.c:3385 v4l2_ioctl+0x1b7/0x250 drivers/media/v4l2-core/v4l2-dev.c:364 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl fs/ioctl.c:856 [inline] __x64_sys_ioctl+0x197/0x210 fs/ioctl.c:856 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f5d2ce8c149 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 19 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f5d2db20168 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f5d2cfabf80 RCX: 00007f5d2ce8c149 RDX: 0000000020000100 RSI: 00000000c100565c RDI: 0000000000000003 RBP: 00007f5d2cee7cad R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f5d2d0cfb1f R14: 00007f5d2db20300 R15: 0000000000022000