INFO: task syz-executor653:3562 blocked for more than 143 seconds. Not tainted 6.1.54-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor653 state:D stack:23728 pid:3562 ppid:3560 flags:0x00004002 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:1459 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: 0033:0x7f18bd322887 RSP: 002b:00007fff03c9d0b8 EFLAGS: 00000206 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f18bd322887 RDX: 0000000000000000 RSI: 000000000000000a RDI: 00007fff03c9d170 RBP: 00007fff03c9d170 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000206 R12: 00007fff03c9e1e0 R13: 00005555566766c0 R14: 431bde82d7b634db R15: 00007fff03c9e200 Showing all locks held in the system: 3 locks held by kworker/u4:1/11: 1 lock held by rcu_tasks_kthre/12: #0: ffffffff8d12a170 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xd20 kernel/rcu/tasks.h:516 1 lock held by rcu_tasks_trace/13: #0: ffffffff8d12a970 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xd20 kernel/rcu/tasks.h:516 1 lock held by khungtaskd/28: #0: ffffffff8d129fa0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 6 locks held by kworker/1:1H/120: #0: ffff8880b9939e18 (&rq->__lock){-.-.}-{2:2}, at: process_one_work+0x77a/0x11f0 #1: ffff8880b9927788 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x43d/0x770 kernel/sched/psi.c:1000 #2: ffffffff8d129fa0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x5/0x30 include/linux/rcupdate.h:305 #3: ffff888142f330d8 (&lo->lo_work_lock){....}-{2:2}, at: spin_lock_irq include/linux/spinlock.h:375 [inline] #3: ffff888142f330d8 (&lo->lo_work_lock){....}-{2:2}, at: loop_queue_work drivers/block/loop.c:838 [inline] #3: ffff888142f330d8 (&lo->lo_work_lock){....}-{2:2}, at: loop_queue_rq+0x21b/0xaa0 drivers/block/loop.c:1849 #4: ffffffff8d129fa0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x5/0x30 include/linux/rcupdate.h:305 #5: ffff888012479818 (&pool->lock/1){..-.}-{2:2}, at: __queue_work+0x56b/0xf50 2 locks held by getty/3310: #0: ffff88814b62b098 (&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:2188 2 locks held by syz-executor653/3562: #0: ffff88807e9ce0e0 (&type->s_umount_key#31){++++}-{3:3}, at: deactivate_super+0xa9/0xe0 fs/super.c:362 #1: ffff888142f387d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:362 [inline] #1: ffff888142f387d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x274/0xab0 fs/fs-writeback.c:2715 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 28 Comm: khungtaskd Not tainted 6.1.54-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/04/2023 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 6.1.54-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/04/2023 Workqueue: writeback wb_workfn (flush-7:0) RIP: 0010:kasan_mem_to_shadow include/linux/kasan.h:60 [inline] RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:128 [inline] RIP: 0010:memory_is_poisoned mm/kasan/generic.c:159 [inline] RIP: 0010:check_region_inline mm/kasan/generic.c:180 [inline] RIP: 0010:kasan_check_range+0x41/0x290 mm/kasan/generic.c:189 Code: 0f 82 5a 02 00 00 48 89 fd 48 c1 ed 2f 81 fd ff ff 01 00 0f 82 47 02 00 00 48 89 fb 48 c1 eb 03 49 b8 00 00 00 00 00 fc ff df <4e> 8d 0c 03 4c 8d 54 37 ff 49 c1 ea 03 49 bb 01 00 00 00 00 fc ff RSP: 0018:ffffc90000106d40 EFLAGS: 00000a02 RAX: ffffffff81b6d601 RBX: 1ffffd40003825a8 RCX: ffffffff81b6d67a RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffea0001c12d40 RBP: 000000000001ffff R08: dffffc0000000000 R09: fffff940003825a9 R10: 0000000000000000 R11: dffffc0000000001 R12: ffffea0001c12d48 R13: 1ffffd40003825a9 R14: ffffea0001c12d40 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055b3a0fabcb8 CR3: 000000000ce8e000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: instrument_atomic_read include/linux/instrumented.h:72 [inline] _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline] folio_test_locked include/linux/page-flags.h:473 [inline] folio_unlock+0x6a/0x2f0 mm/filemap.c:1524 mpage_release_unused_pages+0x748/0xe80 fs/ext4/inode.c:1611 ext4_writepages+0xcd5/0x3de0 fs/ext4/inode.c:2787 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:2292 worker_thread+0xa5f/0x1210 kernel/workqueue.c:2439 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: 1.716 msecs