INFO: task syz-executor:6425 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:22864 pid:6425 ppid:1 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5246 [inline] __schedule+0x107f/0x4030 kernel/sched/core.c:6563 schedule+0xb9/0x180 kernel/sched/core.c:6639 wb_wait_for_completion+0x16f/0x290 fs/fs-writeback.c:191 sync_inodes_sb+0x1c5/0xa10 fs/fs-writeback.c:2807 sync_filesystem+0x16d/0x220 fs/sync.c:64 generic_shutdown_super+0x6b/0x340 fs/super.c:474 kill_block_super+0x7c/0xe0 fs/super.c:1470 deactivate_locked_super+0x93/0xf0 fs/super.c:332 cleanup_mnt+0x471/0x4f0 fs/namespace.c:1191 task_work_run+0x1d0/0x260 kernel/task_work.c:203 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop+0xe6/0x110 kernel/entry/common.c:177 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fbf4759f0d7 RSP: 002b:00007ffca9f037f8 EFLAGS: 00000202 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 0000000000000064 RCX: 00007fbf4759f0d7 RDX: 0000000000000200 RSI: 0000000000000009 RDI: 00007ffca9f049a0 RBP: 00007fbf4763330a R08: 0000000000010590 R09: 00000000ffffffff R10: 0000000000000100 R11: 0000000000000202 R12: 00007ffca9f049a0 R13: 00007fbf4763330a R14: 00005555874764e8 R15: 00007ffca9f05a70 Showing all locks held in the system: 1 lock held by rcu_tasks_kthre/12: #0: ffffffff8cb2e4f0 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xef0 kernel/rcu/tasks.h:517 1 lock held by rcu_tasks_trace/13: #0: ffffffff8cb2ed10 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xef0 kernel/rcu/tasks.h:517 1 lock held by khungtaskd/28: #0: ffffffff8cb2db60 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #0: ffffffff8cb2db60 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #0: ffffffff8cb2db60 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6527 2 locks held by getty/4025: #0: ffff88814d143098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244 #1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x41e/0x1360 drivers/tty/n_tty.c:2198 2 locks held by syz-executor/6425: #0: ffff88807b3340e0 (&type->s_umount_key#84){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:362 #1: ffff8880246a4820 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:362 [inline] #1: ffff8880246a4820 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x1a9/0xa10 fs/fs-writeback.c:2805 2 locks held by kworker/u4:13/6540: #0: ffff888019ed1938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267 #1: ffffc90003bd7d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267 1 lock held by segctord/8224: 2 locks held by rm/10495: ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 28 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026 Call Trace: dump_stack_lvl+0x188/0x24e lib/dump_stack.c:106 nmi_cpu_backtrace+0x3e6/0x460 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x1d4/0x450 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+0xf0e/0xf50 kernel/hung_task.c:377 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 15 Comm: ksoftirqd/0 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026 RIP: 0010:jhash2 include/linux/jhash.h:129 [inline] RIP: 0010:hash_stack lib/stackdepot.c:276 [inline] RIP: 0010:__stack_depot_save+0xba/0x480 lib/stackdepot.c:444 Code: 45 89 d3 41 c1 c3 08 44 29 d5 41 31 eb 45 01 ca 45 29 d9 44 89 de c1 c6 10 44 31 ce 45 01 d3 89 f2 c1 c2 13 41 29 f2 44 31 d2 <44> 01 de 41 29 d3 89 d5 c1 c5 04 44 31 dd 01 f2 41 83 c0 fd 48 83 RSP: 0018:ffffc90000147578 EFLAGS: 00000286 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000010 RDX: 0000000097b9a006 RSI: 0000000026f4875c RDI: ffffc90000147634 RBP: 00000000a2156c8e R08: 000000000000000b R09: 00000000d83c32a4 R10: 00000000ad5897a2 R11: 000000008a461dc6 R12: 0000000000000001 R13: ffffc900001478c0 R14: ffffc900001475e0 R15: 0000000000000800 FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffed3639d18 CR3: 0000000024b3b000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_set_track+0x60/0x70 mm/kasan/common.c:53 kasan_save_free_info+0x27/0x40 mm/kasan/generic.c:516 ____kasan_slab_free+0x126/0x1f0 mm/kasan/common.c:237 kasan_slab_free include/linux/kasan.h:177 [inline] slab_free_hook mm/slub.c:1729 [inline] slab_free_freelist_hook+0x133/0x1b0 mm/slub.c:1755 slab_free mm/slub.c:3687 [inline] kmem_cache_free+0xf7/0x2a0 mm/slub.c:3709 can_receive+0x3b1/0x440 net/can/af_can.c:670 can_rcv+0x141/0x260 net/can/af_can.c:689 __netif_receive_skb_one_core net/core/dev.c:5619 [inline] __netif_receive_skb+0xcc/0x290 net/core/dev.c:5733 process_backlog+0x37c/0x710 net/core/dev.c:6061 __napi_poll+0xbb/0x460 net/core/dev.c:6628 napi_poll net/core/dev.c:6695 [inline] net_rx_action+0x622/0xbc0 net/core/dev.c:6809 handle_softirqs+0x291/0x910 kernel/softirq.c:596 run_ksoftirqd+0xa4/0x100 kernel/softirq.c:968 smpboot_thread_fn+0x667/0xa30 kernel/smpboot.c:164 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295