INFO: task syz-executor.4:17524 blocked for more than 143 seconds. Not tainted 6.4.0-syzkaller-01554-g6f612579be9d #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.4 state:D stack:24752 pid:17524 ppid:17444 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5381 [inline] __schedule+0x187b/0x4900 kernel/sched/core.c:6707 schedule+0xc3/0x180 kernel/sched/core.c:6783 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6842 __mutex_lock_common+0xe33/0x2530 kernel/locking/mutex.c:679 __mutex_lock kernel/locking/mutex.c:747 [inline] mutex_lock_nested+0x1b/0x20 kernel/locking/mutex.c:799 eventpoll_release_file+0xcb/0x1c0 fs/eventpoll.c:965 eventpoll_release include/linux/eventpoll.h:53 [inline] __fput+0x744/0x950 fs/file_table.c:369 task_work_run+0x24a/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+0x64/0x280 kernel/entry/common.c:297 do_syscall_64+0x4d/0xc0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7feec083e12b RSP: 002b:00007ffe2aba63d0 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000004 RCX: 00007feec083e12b RDX: 0000001b2d920000 RSI: 000000000000b8d9 RDI: 0000000000000003 RBP: 00007feec09ad980 R08: 0000000000000000 R09: 000000008184cbb5 R10: 00007ffe2abf9080 R11: 0000000000000293 R12: 00000000001d977d R13: 00007ffe2aba64d0 R14: 00007ffe2aba64f0 R15: 0000000000000032 Showing all locks held in the system: 1 lock held by rcu_tasks_kthre/13: #0: ffffffff8cf272b0 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xd20 kernel/rcu/tasks.h:522 1 lock held by rcu_tasks_trace/14: #0: ffffffff8cf27670 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xd20 kernel/rcu/tasks.h:522 1 lock held by khungtaskd/28: #0: ffffffff8cf270e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 2 locks held by getty/4746: #0: ffff88814a95a098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900015b02f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6b1/0x1db0 drivers/tty/n_tty.c:2176 2 locks held by kworker/u4:6/20232: 1 lock held by syz-executor.4/17524: #0: ffff88802ae80068 (&ep->mtx){+.+.}-{3:3}, at: eventpoll_release_file+0xcb/0x1c0 fs/eventpoll.c:965 3 locks held by syz-executor.4/17525: 1 lock held by syz-executor.4/17595: #0: ffff88801e9e2068 (&ep->mtx){+.+.}-{3:3}, at: eventpoll_release_file+0xcb/0x1c0 fs/eventpoll.c:965 2 locks held by syz-executor.4/17596: 1 lock held by syz-executor.1/17603: #0: ffff88805196b068 (&ep->mtx){+.+.}-{3:3}, at: eventpoll_release_file+0xcb/0x1c0 fs/eventpoll.c:965 2 locks held by syz-executor.1/17610: ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 28 Comm: khungtaskd Not tainted 6.4.0-syzkaller-01554-g6f612579be9d #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+0x1e7/0x2d0 lib/dump_stack.c:106 nmi_cpu_backtrace+0x498/0x4d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x187/0x300 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+0xec2/0xf00 kernel/hung_task.c:379 kthread+0x2b8/0x350 kernel/kthread.c:389 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 17525 Comm: syz-executor.4 Not tainted 6.4.0-syzkaller-01554-g6f612579be9d #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/27/2023 RIP: 0010:__sanitizer_cov_trace_const_cmp8+0x7c/0x80 kernel/kcov.c:313 Code: c1 e1 05 48 8d 41 28 4c 39 c8 77 1e 49 ff c2 4c 89 12 48 c7 44 11 08 07 00 00 00 48 89 7c 11 10 48 89 74 11 18 4c 89 44 11 20 0f 1f 00 f3 0f 1e fa 41 57 41 56 41 54 53 4c 8b 16 48 8b 46 08 RSP: 0018:ffffc9000c0ae298 EFLAGS: 00000097 RAX: 0000000000000002 RBX: ffffc9000c0aec6c RCX: ffff8880586ad940 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc9000c0ae4b0 R08: ffffffff81c49a84 R09: fffff9400046a9d1 R10: 0000000000000000 R11: dffffc0000000001 R12: ffff888059d11020 R13: ffffea0002354e80 R14: ffffea0002354e88 R15: 00fff00000000011 FS: 00007feec16cf700(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055c2179d8050 CR3: 000000002f4d7000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: constant_test_bit arch/x86/include/asm/bitops.h:207 [inline] arch_test_bit arch/x86/include/asm/bitops.h:239 [inline] _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:142 [inline] folio_test_head include/linux/page-flags.h:769 [inline] folio_test_large include/linux/page-flags.h:790 [inline] folio_nr_pages include/linux/mm.h:1998 [inline] isolate_lru_folios+0x304/0x1500 mm/vmscan.c:2301 shrink_inactive_list mm/vmscan.c:2573 [inline] shrink_list mm/vmscan.c:2829 [inline] shrink_lruvec+0x1533/0x2d30 mm/vmscan.c:6265 shrink_node_memcgs mm/vmscan.c:6452 [inline] shrink_node+0x115c/0x2790 mm/vmscan.c:6487 shrink_zones mm/vmscan.c:6722 [inline] do_try_to_free_pages+0x67e/0x1900 mm/vmscan.c:6784 try_to_free_mem_cgroup_pages+0x455/0xa50 mm/vmscan.c:7099 try_charge_memcg+0x5de/0x16d0 mm/memcontrol.c:2724 obj_cgroup_charge_pages mm/memcontrol.c:3138 [inline] obj_cgroup_charge+0x2b2/0x410 mm/memcontrol.c:3428 memcg_slab_pre_alloc_hook mm/slab.h:503 [inline] slab_pre_alloc_hook+0x282/0x2b0 mm/slab.h:714 slab_alloc_node mm/slub.c:3462 [inline] slab_alloc mm/slub.c:3488 [inline] __kmem_cache_alloc_lru mm/slub.c:3495 [inline] kmem_cache_alloc_lru+0x4e/0x300 mm/slub.c:3511 xas_nomem+0x141/0x1e0 lib/xarray.c:306 __filemap_add_folio+0xa4a/0x1b60 mm/filemap.c:915 filemap_add_folio+0x121/0x580 mm/filemap.c:939 page_cache_ra_unbounded+0x210/0x7c0 mm/readahead.c:251 do_sync_mmap_readahead+0x7b6/0x9a0 mm/filemap.c:3210 filemap_fault+0x81b/0x1810 mm/filemap.c:3302 __do_fault+0x136/0x500 mm/memory.c:4176 do_cow_fault mm/memory.c:4560 [inline] do_fault mm/memory.c:4661 [inline] do_pte_missing mm/memory.c:3647 [inline] handle_pte_fault mm/memory.c:4947 [inline] __handle_mm_fault mm/memory.c:5089 [inline] handle_mm_fault+0x2ad6/0x5860 mm/memory.c:5243 do_user_addr_fault arch/x86/mm/fault.c:1440 [inline] handle_page_fault arch/x86/mm/fault.c:1534 [inline] exc_page_fault+0x7d2/0x910 arch/x86/mm/fault.c:1590 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:570 RIP: 0010:__put_user_nocheck_4+0xb/0x20 arch/x86/lib/putuser.S:101 Code: 0f 1e fa 48 89 cb 48 c1 fb 3f 48 09 d9 0f 01 cb 89 01 31 c9 0f 01 ca c3 0f 1f 80 00 00 00 00 f3 0f 1e fa f3 0f 1e fa 0f 01 cb <89> 01 31 c9 0f 01 ca c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 f3 RSP: 0018:ffffc9000c0afb78 EFLAGS: 00050246 RAX: 0000000000000004 RBX: dffffc0000000000 RCX: 0000000020000040 RDX: ffff8880586ad940 RSI: 0000000000000004 RDI: ffff88802b6821f3 RBP: ffffc9000c0afdd8 R08: ffffffff82086c9d R09: ffffed1005a9dc4f R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000000 R13: 0000000000000004 R14: 0000000020000040 R15: ffff88802b682198 epoll_put_uevent include/linux/eventpoll.h:81 [inline] ep_send_events fs/eventpoll.c:1743 [inline] ep_poll+0xbba/0x1c70 fs/eventpoll.c:1872 do_epoll_wait fs/eventpoll.c:2326 [inline] do_epoll_pwait+0x1da/0x320 fs/eventpoll.c:2360 __do_sys_epoll_pwait fs/eventpoll.c:2373 [inline] __se_sys_epoll_pwait fs/eventpoll.c:2367 [inline] __x64_sys_epoll_pwait+0x2b8/0x310 fs/eventpoll.c:2367 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7feec088c389 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:00007feec16cf168 EFLAGS: 00000246 ORIG_RAX: 0000000000000119 RAX: ffffffffffffffda RBX: 00007feec09abf80 RCX: 00007feec088c389 RDX: 0000000000000001 RSI: 0000000020000040 RDI: 0000000000000004 RBP: 00007feec08d7493 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffe2aba636f R14: 00007feec16cf300 R15: 0000000000022000