INFO: task syz.4.302:7285 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.302 state:D stack:27560 pid:7285 ppid:6212 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5380 [inline] __schedule+0x14d2/0x44d0 kernel/sched/core.c:6699 schedule+0xbd/0x170 kernel/sched/core.c:6773 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6832 rwsem_down_read_slowpath+0x4f8/0x840 kernel/locking/rwsem.c:1086 __down_read_common kernel/locking/rwsem.c:1250 [inline] __down_read kernel/locking/rwsem.c:1263 [inline] down_read+0x98/0x2e0 kernel/locking/rwsem.c:1522 __super_lock fs/super.c:58 [inline] super_lock+0x167/0x360 fs/super.c:117 super_lock_shared fs/super.c:146 [inline] iterate_supers+0x80/0x170 fs/super.c:977 ksys_sync+0x95/0x150 fs/sync.c:102 __ia32_sys_sync+0xe/0x20 fs/sync.c:113 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f584a38f749 RSP: 002b:00007f584b253038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 00007f584a5e5fa0 RCX: 00007f584a38f749 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007f584a5e5fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f584a5e6038 R14: 00007f584a5e5fa0 R15: 00007fff34963ce8 Showing all locks held in the system: 1 lock held by khungtaskd/29: #0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline] #0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline] #0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633 2 locks held by getty/5526: #0: ffff8880204900a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000326e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x425/0x1380 drivers/tty/n_tty.c:2217 1 lock held by syz-executor/5769: #0: ffff88802db280e0 (&type->s_umount_key#91){++++}-{3:3}, at: __super_lock fs/super.c:56 [inline] #0: ffff88802db280e0 (&type->s_umount_key#91){++++}-{3:3}, at: __super_lock_excl fs/super.c:71 [inline] #0: ffff88802db280e0 (&type->s_umount_key#91){++++}-{3:3}, at: deactivate_super+0xa4/0xe0 fs/super.c:513 2 locks held by kworker/0:4/5814: #0: ffff888017872538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #0: ffff888017872538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #1: ffffc90004997d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #1: ffffc90004997d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 1 lock held by syz.4.302/7285: #0: ffff88802db280e0 (&type->s_umount_key#91){++++}-{3:3}, at: __super_lock fs/super.c:58 [inline] #0: ffff88802db280e0 (&type->s_umount_key#91){++++}-{3:3}, at: super_lock+0x167/0x360 fs/super.c:117 1 lock held by syz.8.725/9026: #0: ffff88805d39e0e0 (&type->s_umount_key#61/1){+.+.}-{3:3}, at: alloc_super+0x1fa/0x920 fs/super.c:352 4 locks held by kvm-nx-lpage-re/9033: #0: ffffffff8cd59988 (cgroup_mutex){+.+.}-{3:3}, at: cgroup_lock include/linux/cgroup.h:369 [inline] #0: ffffffff8cd59988 (cgroup_mutex){+.+.}-{3:3}, at: cgroup_attach_task_all+0x26/0xe0 kernel/cgroup/cgroup-v1.c:61 #1: ffffffff8cbcb210 (cpu_hotplug_lock){++++}-{0:0}, at: cgroup_attach_lock+0x11/0x30 kernel/cgroup/cgroup.c:2414 #2: ffffffff8cd59b70 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: cgroup_attach_task_all+0x30/0xe0 kernel/cgroup/cgroup-v1.c:62 #3: ffffffff8cd358f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:292 [inline] #3: ffffffff8cd358f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x448/0x830 kernel/rcu/tree_exp.h:1004 1 lock held by syz.0.730/9040: ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 29 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106 nmi_cpu_backtrace+0x39b/0x3d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x2f0 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline] watchdog+0xf41/0xf80 kernel/hung_task.c:379 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 9040 Comm: syz.0.730 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:check_preemption_disabled+0x37/0x110 lib/smp_processor_id.c:55 Code: 04 25 28 00 00 00 48 89 44 24 08 65 8b 05 2d 29 9c 75 65 8b 0d 22 29 9c 75 f7 c1 ff ff ff 7f 74 1f 65 48 8b 0c 25 28 00 00 00 <48> 3b 4c 24 08 0f 85 c4 00 00 00 48 83 c4 10 5b 41 5e 41 5f 5d c3 RSP: 0018:ffffc9000b687538 EFLAGS: 00000002 RAX: 0000000000000001 RBX: ffff8880314d3c00 RCX: ced1ed79a364d600 RDX: ffff8880314d3c00 RSI: ffffffff8aaace60 RDI: ffffffff8afc6f80 RBP: 0000000000000001 R08: ffffea00010fb587 R09: 1ffffd400021f6b0 R10: dffffc0000000000 R11: fffff9400021f6b1 R12: 0000000000000000 R13: 0000000000000046 R14: ffff888023f68068 R15: ffff8880314d46e0 FS: 00007f19b815d6c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f39a6f72a60 CR3: 000000006472a000 CR4: 00000000003526e0 Call Trace: lockdep_recursion_finish kernel/locking/lockdep.c:467 [inline] lock_is_held_type+0x104/0x190 kernel/locking/lockdep.c:5826 lock_is_held include/linux/lockdep.h:288 [inline] __update_lru_size include/linux/mm_inline.h:43 [inline] lru_gen_update_size+0x57a/0xe90 include/linux/mm_inline.h:206 lru_gen_del_folio+0x323/0x6d0 include/linux/mm_inline.h:287 lruvec_del_folio include/linux/mm_inline.h:350 [inline] release_pages+0x9a9/0x2220 mm/swap.c:1012 __folio_batch_release+0x71/0xe0 mm/swap.c:1042 folio_batch_release include/linux/pagevec.h:83 [inline] shmem_undo_range+0x5d0/0x1a40 mm/shmem.c:1026 shmem_truncate_range mm/shmem.c:1135 [inline] shmem_evict_inode+0x273/0xa70 mm/shmem.c:1264 evict+0x486/0x870 fs/inode.c:705 __dentry_kill+0x431/0x650 fs/dcache.c:611 dentry_kill+0xb8/0x290 fs/dcache.c:-1 dput+0xfe/0x1e0 fs/dcache.c:918 __fput+0x5e5/0x970 fs/file_table.c:392 __do_sys_close fs/open.c:1573 [inline] __se_sys_close+0x15f/0x220 fs/open.c:1558 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f19b738e3aa Code: 48 3d 00 f0 ff ff 77 48 c3 0f 1f 80 00 00 00 00 48 83 ec 18 89 7c 24 0c e8 43 91 02 00 8b 7c 24 0c 89 c2 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 36 89 d7 89 44 24 0c e8 a3 91 02 00 8b 44 24 RSP: 002b:00007f19b815ce00 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: ffffffffffffffda RBX: 00000000ffffffff RCX: 00007f19b738e3aa RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000005 RBP: 0000000000000002 R08: 0000000000000000 R09: 0000000000004466 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000005 R13: 00007f19b815cef0 R14: 00007f19b815ceb0 R15: 00007f19ad1f7000