INFO: task syz-executor:5852 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:23720 pid:5852 tgid:5852 ppid:1 task_flags:0x400140 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1190/0x5de0 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:7058 netfs_wait_for_outstanding_io include/linux/netfs.h:552 [inline] v9fs_evict_inode+0x26f/0x300 fs/9p/vfs_inode.c:348 evict+0x3e3/0x920 fs/inode.c:810 iput_final fs/inode.c:1897 [inline] iput fs/inode.c:1923 [inline] iput+0x521/0x880 fs/inode.c:1909 dentry_unlink_inode+0x29c/0x480 fs/dcache.c:466 __dentry_kill+0x1d0/0x600 fs/dcache.c:669 dput.part.0+0x4b1/0x9b0 fs/dcache.c:911 dput fs/dcache.c:901 [inline] do_one_tree fs/dcache.c:1607 [inline] shrink_dcache_for_umount+0x159/0x3e0 fs/dcache.c:1621 generic_shutdown_super+0x6c/0x390 fs/super.c:621 kill_anon_super+0x3a/0x60 fs/super.c:1282 v9fs_kill_super+0x3d/0xa0 fs/9p/vfs_super.c:195 deactivate_locked_super+0xc1/0x1a0 fs/super.c:474 deactivate_super fs/super.c:507 [inline] deactivate_super+0xde/0x100 fs/super.c:503 cleanup_mnt+0x225/0x450 fs/namespace.c:1375 task_work_run+0x14d/0x240 kernel/task_work.c:227 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop+0xeb/0x110 kernel/entry/common.c:43 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline] do_syscall_64+0x3f6/0x4c0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f878058ff17 RSP: 002b:00007ffd2bd0ce48 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007f8780611c05 RCX: 00007f878058ff17 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffd2bd0cf00 RBP: 00007ffd2bd0cf00 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffd2bd0df90 R13: 00007f8780611c05 R14: 00000000000d6e92 R15: 00007ffd2bd0dfd0 INFO: task syz.3.2804:22333 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.2804 state:D stack:28072 pid:22333 tgid:22332 ppid:5853 task_flags:0x400040 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1190/0x5de0 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:7058 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7115 rwsem_down_read_slowpath+0x64e/0xbf0 kernel/locking/rwsem.c:1086 __down_read_common kernel/locking/rwsem.c:1261 [inline] __down_read kernel/locking/rwsem.c:1274 [inline] down_read+0xef/0x480 kernel/locking/rwsem.c:1539 __super_lock fs/super.c:59 [inline] super_lock+0x31c/0x3f0 fs/super.c:121 __iterate_supers+0x1e0/0x360 fs/super.c:923 quota_sync_all fs/quota/quota.c:69 [inline] __do_sys_quotactl fs/quota/quota.c:938 [inline] __se_sys_quotactl fs/quota/quota.c:917 [inline] __x64_sys_quotactl+0x2b3/0x440 fs/quota/quota.c:917 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fd762b8ebe9 RSP: 002b:00007fd763932038 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3 RAX: ffffffffffffffda RBX: 00007fd762db5fa0 RCX: 00007fd762b8ebe9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff80000100 RBP: 00007fd762c11e19 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fd762db6038 R14: 00007fd762db5fa0 R15: 00007ffe0f057d38 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e5c1220 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e5c1220 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e5c1220 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6775 2 locks held by getty/5611: #0: ffff88814d5790a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222 1 lock held by syz-executor/5852: #0: ffff888042c6e0e0 (&type->s_umount_key#90){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff888042c6e0e0 (&type->s_umount_key#90){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff888042c6e0e0 (&type->s_umount_key#90){++++}-{4:4}, at: deactivate_super fs/super.c:506 [inline] #0: ffff888042c6e0e0 (&type->s_umount_key#90){++++}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:503 2 locks held by kworker/u8:10/14333: #0: ffff8880b843a318 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested kernel/sched/core.c:644 [inline] #0: ffff8880b843a318 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x7e/0x130 kernel/sched/core.c:629 #1: ffff8880b8524088 (psi_seq){-.-.}-{0:0}, at: psi_sched_switch kernel/sched/stats.h:220 [inline] #1: ffff8880b8524088 (psi_seq){-.-.}-{0:0}, at: __schedule+0x1861/0x5de0 kernel/sched/core.c:6955 1 lock held by syz.3.2804/22333: #0: ffff888042c6e0e0 (&type->s_umount_key#90){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline] #0: ffff888042c6e0e0 (&type->s_umount_key#90){++++}-{4:4}, at: super_lock+0x31c/0x3f0 fs/super.c:121 1 lock held by syz.5.3025/24978: #0: ffff888042c6e0e0 (&type->s_umount_key#90){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline] #0: ffff888042c6e0e0 (&type->s_umount_key#90){++++}-{4:4}, at: super_lock+0x31c/0x3f0 fs/super.c:121 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x29c/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:328 [inline] watchdog+0xf0e/0x1260 kernel/hung_task.c:491 kthread+0x3c2/0x780 kernel/kthread.c:463 ret_from_fork+0x5d7/0x6f0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 3565 Comm: kworker/u8:8 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:lookup_chain_cache kernel/locking/lockdep.c:3801 [inline] RIP: 0010:lookup_chain_cache_add kernel/locking/lockdep.c:3821 [inline] RIP: 0010:validate_chain kernel/locking/lockdep.c:3876 [inline] RIP: 0010:__lock_acquire+0xbc1/0x1ce0 kernel/locking/lockdep.c:5237 Code: 4c 8b 04 24 48 b8 eb 83 b5 80 46 86 c8 61 49 0f af c0 48 c1 e8 2d 48 89 04 24 4c 8d 3c c5 20 9a 1a 97 48 8b 04 c5 20 9a 1a 97 <48> 8d 48 f8 48 85 c0 48 0f 45 c1 eb 04 48 83 e8 08 48 85 c0 74 16 RSP: 0018:ffffc9000c3a7850 EFLAGS: 00000002 RAX: ffffffff93dd5488 RBX: ffff888032725370 RCX: 00000000fc74e1c9 RDX: 9a3d7139bc4d7644 RSI: 0000000024da71ee RDI: ffff8880327253c0 RBP: 0000000000000000 R08: 9a3d7139bc4d7644 R09: 0000000000000001 R10: 0000000000000002 R11: 0000000000000000 R12: ffff8880327253c0 R13: ffff888032724880 R14: 0000000030b6a61f R15: ffffffff9723fbb0 FS: 0000000000000000(0000) GS:ffff8881247bb000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffde0076ef8 CR3: 000000000e380000 CR4: 00000000003526f0 Call Trace: lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x179/0x350 kernel/locking/lockdep.c:5825 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162 lock_timer_base+0x127/0x1d0 kernel/time/timer.c:1004 __mod_timer+0x425/0xd30 kernel/time/timer.c:1085 add_timer_global+0x8a/0xc0 kernel/time/timer.c:1283 __queue_delayed_work+0x33a/0x460 kernel/workqueue.c:2524 queue_delayed_work_on+0x1b5/0x200 kernel/workqueue.c:2559 queue_delayed_work include/linux/workqueue.h:684 [inline] toggle_allocation_gate mm/kfence/core.c:857 [inline] toggle_allocation_gate+0x18a/0x280 mm/kfence/core.c:842 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3236 process_scheduled_works kernel/workqueue.c:3319 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400 kthread+0x3c2/0x780 kernel/kthread.c:463 ret_from_fork+0x5d7/0x6f0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245