INFO: task syz-executor.3:3636 blocked for more than 143 seconds. Not tainted 5.15.106-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.3 state:D stack:18904 pid: 3636 ppid: 1 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5026 [inline] __schedule+0x12c4/0x4590 kernel/sched/core.c:6372 schedule+0x11b/0x1f0 kernel/sched/core.c:6455 wb_wait_for_completion+0x164/0x290 fs/fs-writeback.c:191 sync_inodes_sb+0x293/0xab0 fs/fs-writeback.c:2745 sync_filesystem+0x16b/0x220 fs/sync.c:64 generic_shutdown_super+0x6e/0x2c0 fs/super.c:448 kill_block_super+0x7a/0xe0 fs/super.c:1405 deactivate_locked_super+0xa0/0x110 fs/super.c:335 cleanup_mnt+0x44e/0x500 fs/namespace.c:1143 task_work_run+0x129/0x1a0 kernel/task_work.c:164 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop+0x106/0x130 kernel/entry/common.c:175 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:208 __syscall_exit_to_user_mode_work kernel/entry/common.c:290 [inline] syscall_exit_to_user_mode+0x5d/0x250 kernel/entry/common.c:301 do_syscall_64+0x49/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7f0b8239d5d7 RSP: 002b:00007ffe8d0dceb8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f0b8239d5d7 RDX: 00007ffe8d0dcf8b RSI: 000000000000000a RDI: 00007ffe8d0dcf80 RBP: 00007ffe8d0dcf80 R08: 00000000ffffffff R09: 00007ffe8d0dcd50 R10: 0000555556b108b3 R11: 0000000000000246 R12: 00007f0b823f6cdc R13: 00007ffe8d0de040 R14: 0000555556b10810 R15: 00007ffe8d0de080 Showing all locks held in the system: 1 lock held by khungtaskd/27: #0: ffffffff8c91b920 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 2 locks held by kworker/u4:1/144: #0: ffff8880155d4138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2279 #1: ffffc900012dfd20 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2281 2 locks held by getty/3270: #0: ffff88814b0d8098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252 #1: ffffc90002bb32e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6af/0x1da0 drivers/tty/n_tty.c:2147 2 locks held by syz-executor.3/3636: #0: ffff888035e5c0e0 (&type->s_umount_key#54){++++}-{3:3}, at: deactivate_super+0xa9/0xe0 fs/super.c:365 #1: ffff8881476987d8 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:362 [inline] #1: ffff8881476987d8 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x274/0xab0 fs/fs-writeback.c:2743 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 27 Comm: khungtaskd Not tainted 5.15.106-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/30/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106 nmi_cpu_backtrace+0x46a/0x4a0 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x181/0x2a0 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:210 [inline] watchdog+0xe72/0xeb0 kernel/hung_task.c:295 kthread+0x3f6/0x4f0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 2113 Comm: kworker/1:2 Not tainted 5.15.106-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/30/2023 Workqueue: events nsim_dev_trap_report_work RIP: 0010:on_stack arch/x86/include/asm/stacktrace.h:55 [inline] RIP: 0010:stack_access_ok arch/x86/kernel/unwind_orc.c:347 [inline] RIP: 0010:deref_stack_reg+0x34/0x110 arch/x86/kernel/unwind_orc.c:357 Code: 49 89 d6 49 89 f7 48 89 fb 49 bc 00 00 00 00 00 fc ff df 48 83 c7 08 48 89 f8 48 c1 e8 03 42 80 3c 20 00 74 05 e8 dc ba 90 00 <4c> 8b 6b 08 48 8d 7b 10 48 89 f8 48 c1 e8 03 42 80 3c 20 00 74 05 RSP: 0018:ffffc90006817530 EFLAGS: 00000246 RAX: 1ffff92000d02ec5 RBX: ffffc90006817620 RCX: 0000000000000000 RDX: ffffc90006817660 RSI: ffffc90006817a68 RDI: ffffc90006817628 RBP: ffffffff8e627ac0 R08: ffffc90006817a68 R09: ffffc90006817670 R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000 R13: 1ffffffff1cc4f58 R14: ffffc90006817660 R15: ffffc90006817a68 FS: 0000000000000000(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f3d30814000 CR3: 000000002341a000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: unwind_next_frame+0x12f1/0x1fa0 arch_stack_walk+0x10d/0x140 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x113/0x1c0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track+0x4b/0x80 mm/kasan/common.c:46 kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:360 ____kasan_slab_free+0xd8/0x120 mm/kasan/common.c:366 kasan_slab_free include/linux/kasan.h:230 [inline] slab_free_hook mm/slub.c:1705 [inline] slab_free_freelist_hook+0xdd/0x160 mm/slub.c:1731 slab_free mm/slub.c:3499 [inline] kfree+0xf1/0x270 mm/slub.c:4559 skb_free_head net/core/skbuff.c:655 [inline] skb_release_data+0x73a/0x8a0 net/core/skbuff.c:677 skb_release_all net/core/skbuff.c:742 [inline] __kfree_skb net/core/skbuff.c:756 [inline] consume_skb+0xa3/0x140 net/core/skbuff.c:914 nsim_dev_trap_report drivers/net/netdevsim/dev.c:740 [inline] nsim_dev_trap_report_work+0x788/0xab0 drivers/net/netdevsim/dev.c:765 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2306 worker_thread+0xaca/0x1280 kernel/workqueue.c:2453 kthread+0x3f6/0x4f0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298