INFO: task syz.0.1165:8812 blocked for more than 143 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.1165 state:D stack:25544 pid:8812 tgid:8811 ppid:5845 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5295 [inline] __schedule+0x153e/0x4fe0 kernel/sched/core.c:6907 __schedule_loop kernel/sched/core.c:6989 [inline] schedule+0x164/0x360 kernel/sched/core.c:7004 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7061 __mutex_lock_common kernel/locking/mutex.c:692 [inline] __mutex_lock+0x7fe/0x1300 kernel/locking/mutex.c:776 nfsd_shutdown_threads+0x4e/0xd0 fs/nfsd/nfssvc.c:575 nfsd_umount+0x41/0x60 fs/nfsd/nfsctl.c:1353 deactivate_locked_super+0xbc/0x130 fs/super.c:476 cleanup_mnt+0x437/0x4d0 fs/namespace.c:1312 task_work_run+0x1d9/0x270 kernel/task_work.c:233 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] __exit_to_user_mode_loop kernel/entry/common.c:67 [inline] exit_to_user_mode_loop+0xed/0x480 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline] do_syscall_64+0x2b7/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fcc8d39acb9 RSP: 002b:00007fcc8e1b3028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: fffffffffffffffe RBX: 00007fcc8d615fa0 RCX: 00007fcc8d39acb9 RDX: 0000200000002280 RSI: 0000200000000100 RDI: 0000000000000000 RBP: 00007fcc8d408bf7 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fcc8d616038 R14: 00007fcc8d615fa0 R15: 00007ffd9b824288 INFO: task syz.4.1184:8896 blocked for more than 143 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.1184 state:D stack:26912 pid:8896 tgid:8895 ppid:8834 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5295 [inline] __schedule+0x153e/0x4fe0 kernel/sched/core.c:6907 __schedule_loop kernel/sched/core.c:6989 [inline] schedule+0x164/0x360 kernel/sched/core.c:7004 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7061 rwsem_down_read_slowpath+0x61e/0x920 kernel/locking/rwsem.c:1086 __down_read_common kernel/locking/rwsem.c:1261 [inline] __down_read kernel/locking/rwsem.c:1274 [inline] down_read+0x99/0x2e0 kernel/locking/rwsem.c:1539 __super_lock fs/super.c:60 [inline] super_lock+0x2d6/0x3d0 fs/super.c:122 __iterate_supers+0x126/0x290 fs/super.c:926 quota_sync_all fs/quota/quota.c:69 [inline] __do_sys_quotactl fs/quota/quota.c:938 [inline] __se_sys_quotactl+0x3a7/0x9e0 fs/quota/quota.c:917 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f2745f9acb9 RSP: 002b:00007f2746e9a028 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3 RAX: ffffffffffffffda RBX: 00007f2746215fa0 RCX: 00007f2745f9acb9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff80000102 RBP: 00007f2746008bf7 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f2746216038 R14: 00007f2746215fa0 R15: 00007fff6db082e8 Showing all locks held in the system: 3 locks held by kworker/u8:0/12: #0: ffff8880b853abe0 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x31/0x150 kernel/sched/core.c:647 #1: ffff8880b8524588 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880 kernel/sched/psi.c:933 #2: ffff88801e6e2890 (&p->pi_lock){-.-.}-{2:2}, at: class_raw_spinlock_irqsave_constructor include/linux/spinlock.h:573 [inline] #2: ffff88801e6e2890 (&p->pi_lock){-.-.}-{2:2}, at: try_to_wake_up+0x66/0x12a0 kernel/sched/core.c:4130 1 lock held by khungtaskd/31: #0: ffffffff8e75dde0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8e75dde0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8e75dde0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by getty/5583: #0: ffff8880375000a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332e2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13c0 drivers/tty/n_tty.c:2211 2 locks held by syz.1.1132/8733: #0: ffffffff8fc445f0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8ea7f868 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x141/0x16c0 fs/nfsd/nfsctl.c:1886 2 locks held by syz.0.1165/8812: #0: ffff8880581440e0 (&type->s_umount_key#86){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff8880581440e0 (&type->s_umount_key#86){++++}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline] #0: ffff8880581440e0 (&type->s_umount_key#86){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:508 #1: ffffffff8ea7f868 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x4e/0xd0 fs/nfsd/nfssvc.c:575 1 lock held by syz.4.1184/8896: #0: ffff8880581440e0 (&type->s_umount_key#86){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline] #0: ffff8880581440e0 (&type->s_umount_key#86){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122 1 lock held by syz.5.2057/11299: #0: ffff8880581440e0 (&type->s_umount_key#86){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline] #0: ffff8880581440e0 (&type->s_umount_key#86){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122 1 lock held by syz-executor/11700: #0: ffff8880b843abe0 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x31/0x150 kernel/sched/core.c:647 1 lock held by poweroff/12161: #0: ffff8880581440e0 (&type->s_umount_key#86){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline] #0: ffff8880581440e0 (&type->s_umount_key#86){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122 2 locks held by syz.3.2447/12422: #0: ffffffff8fbd6408 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline] #0: ffffffff8fbd6408 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3436 #1: ffffffff8e764078 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline] #1: ffffffff8e764078 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2d0/0x770 kernel/rcu/tree_exp.h:961 1 lock held by syz.7.2449/12427: #0: ffffffff8e763f40 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x580 kernel/rcu/tree.c:3828 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/13/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:161 [inline] __sys_info lib/sys_info.c:157 [inline] sys_info+0x135/0x170 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline] watchdog+0xf90/0xfe0 kernel/hung_task.c:515 kthread+0x388/0x470 kernel/kthread.c:467 ret_from_fork+0x51b/0xa40 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 11598 Comm: syz-executor Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/13/2026 RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:26 [inline] RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:109 [inline] RIP: 0010:arch_local_irq_save arch/x86/include/asm/irqflags.h:127 [inline] RIP: 0010:lock_acquire+0xbe/0x330 kernel/locking/lockdep.c:5864 Code: 98 5b 78 11 85 c0 0f 85 bf 00 00 00 65 48 8b 05 e0 15 78 11 83 b8 14 0b 00 00 00 0f 85 aa 00 00 00 4c 89 74 24 10 4d 89 fe 9c <41> 5f fa 48 c7 c7 3a 96 e0 8d e8 d3 30 ea 09 65 ff 05 5c 5b 78 11 RSP: 0018:ffffc90004ab73b0 EFLAGS: 00000246 RAX: ffff888027428000 RBX: 0000000000000000 RCX: 0000000080000001 RDX: 0000000000000000 RSI: ffffffff81759272 RDI: 1ffffffff1cebbbc RBP: ffffffff81759255 R08: 0000000000000000 R09: 0000000000000000 R10: ffffc90004ab7578 R11: ffffffff81aeeb30 R12: 0000000000000002 R13: ffffffff8e75dde0 R14: 0000000000000000 R15: 0000000000000000 FS: 0000555565c17500(0000) GS:ffff88812529e000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f85c8bdfd58 CR3: 0000000029920000 CR4: 00000000003526f0 Call Trace: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] rcu_read_lock include/linux/rcupdate.h:850 [inline] class_rcu_constructor include/linux/rcupdate.h:1193 [inline] unwind_next_frame+0xc2/0x23c0 arch/x86/kernel/unwind_orc.c:495 arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 poison_kmalloc_redzone mm/kasan/common.c:398 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415 kasan_kmalloc include/linux/kasan.h:263 [inline] __do_kmalloc_node mm/slub.c:5124 [inline] __kvmalloc_node_noprof+0x528/0x8a0 mm/slub.c:6604 translate_table+0x191/0x20b0 net/ipv6/netfilter/ip6_tables.c:695 do_replace net/ipv6/netfilter/ip6_tables.c:1154 [inline] do_ip6t_set_ctl+0x9fe/0xe10 net/ipv6/netfilter/ip6_tables.c:1644 nf_setsockopt+0x26f/0x290 net/netfilter/nf_sockopt.c:101 do_sock_setsockopt+0x17c/0x1b0 net/socket.c:2337 __sys_setsockopt net/socket.c:2362 [inline] __do_sys_setsockopt net/socket.c:2368 [inline] __se_sys_setsockopt net/socket.c:2365 [inline] __x64_sys_setsockopt+0x13d/0x1b0 net/socket.c:2365 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f85c899c51a Code: 48 83 ec 10 48 63 c9 48 63 ff 45 89 c9 6a 2c e8 ec 99 fb ff 48 83 c4 18 c3 0f 1f 80 00 00 00 00 49 89 ca b8 36 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 06 c3 0f 1f 44 00 00 48 c7 c2 e8 ff ff ff f7 RSP: 002b:00007ffc3dd7e1f8 EFLAGS: 00000202 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 00007ffc3dd7e280 RCX: 00007f85c899c51a RDX: 0000000000000040 RSI: 0000000000000029 RDI: 0000000000000003 RBP: 0000000000000003 R08: 00000000000003b8 R09: 0000000000000000 R10: 00007f85c8bdfd00 R11: 0000000000000202 R12: 00007f85c8bdfca0 R13: 00007ffc3dd7e21c R14: 0000000000000000 R15: 00007f85c8be1e60