INFO: task syz.0.546:7267 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.546 state:D stack:26320 pid: 7267 ppid: 6970 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11ef/0x43c0 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6537 rwsem_down_read_slowpath+0x548/0x9d0 kernel/locking/rwsem.c:1055 __down_read_common kernel/locking/rwsem.c:1239 [inline] __down_read kernel/locking/rwsem.c:1252 [inline] down_read+0x96/0x2e0 kernel/locking/rwsem.c:1500 iterate_supers+0xa4/0x1d0 fs/super.c:716 quota_sync_all fs/quota/quota.c:68 [inline] __do_sys_quotactl fs/quota/quota.c:936 [inline] __se_sys_quotactl+0x33b/0x6f0 fs/quota/quota.c:915 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7fe2d5524819 RSP: 002b:00007fe2d375d028 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3 RAX: ffffffffffffffda RBX: 00007fe2d579e090 RCX: 00007fe2d5524819 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff80000100 RBP: 00007fe2d55bac91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fe2d579e128 R14: 00007fe2d579e090 R15: 00007fffc7651158 Showing all locks held in the system: 3 locks held by kworker/0:0/7: #0: ffff888016c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1 #1: ffffc90000cc7d00 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285 #2: ffff88805fc6c240 (&data->fib_lock){+.+.}-{3:3}, at: nsim_fib_event_work+0x26a/0x33e0 drivers/net/netdevsim/fib.c:1480 4 locks held by kworker/u4:0/9: 1 lock held by khungtaskd/27: #0: ffffffff8c31eaa0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 2 locks held by getty/3949: #0: ffff88802c6be098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252 #1: ffffc90002cf62e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x5df/0x1a70 drivers/tty/n_tty.c:2158 1 lock held by syz-executor/4185: #0: ffff88805951e0e0 (&type->s_umount_key#54){++++}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365 1 lock held by syz-executor/4187: #0: ffff8880532440e0 (&type->s_umount_key#54){++++}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365 2 locks held by kworker/0:7/4239: #0: ffff888016c72138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1 #1: ffffc900031afd00 ((work_completion)(&rew.rew_work)){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285 3 locks held by kworker/0:8/4280: #0: ffff888016c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1 #1: ffffc90003297d00 ((work_completion)(&pwq->unbound_release_work)){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285 #2: ffffffff8c323528 ( rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline] rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x2d1/0x750 kernel/rcu/tree_exp.h:845 1 lock held by syz.5.242/5407: #0: ffff888078dd20e0 (&type->s_umount_key#54){++++}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365 1 lock held by syz.8.484/6915: #0: ffff88805fef60e0 (&type->s_umount_key#54){++++}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365 1 lock held by syz-executor/7154: #0: ffff8880604b80e0 (&type->s_umount_key#54){++++}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365 1 lock held by syz.0.546/7267: #0: ffff88805951e0e0 (&type->s_umount_key#54){++++}-{3:3}, at: iterate_supers+0xa4/0x1d0 fs/super.c:716 1 lock held by syz-executor/7743: #0: ffffffff8c323528 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:322 [inline] #0: ffffffff8c323528 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3a5/0x750 kernel/rcu/tree_exp.h:845 1 lock held by syz.6.871/9635: #0: ffffffff8c323430 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0xa1/0x4c0 kernel/rcu/tree.c:4043 6 locks held by syz-executor/9954: 3 locks held by kworker/1:25/10043: #0: ffff88814cb54538 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1 #1: ffffc90003f1fd00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285 #2: ffffffff8d43cb48 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xca/0x1540 net/ipv6/addrconf.c:4110 1 lock held by dhcpcd/10205: #0: ffff88807e210120 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1744 [inline] #0: ffff88807e210120 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x35/0xda0 net/packet/af_packet.c:3212 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 27 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Call Trace: dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106 nmi_cpu_backtrace+0x3a2/0x3d0 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline] watchdog+0xe0f/0xe50 kernel/hung_task.c:369 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 4172 Comm: syz-executor Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 RIP: 0010:__lock_acquire+0x1055/0x7d10 kernel/locking/lockdep.c:5007 Code: 44 89 f3 c1 c3 13 44 29 f1 31 cb 41 01 d6 29 da 41 89 dc 41 c1 c4 04 41 31 d4 48 c7 c0 08 17 8a 8d 48 c1 e8 03 42 0f b6 04 00 <84> c0 0f 85 28 5b 00 00 41 01 de 83 3d 91 01 2d 0c 00 4c 8b 7c 24 RSP: 0018:ffffc90002fefae0 EFLAGS: 00000806 RAX: 0000000000000000 RBX: 00000000e01f8421 RCX: 000000004b4a218c RDX: 000000001fb80772 RSI: 0000000000002862 RDI: ffffffff901d40d0 RBP: ffffc90002fefd30 R08: dffffc0000000000 R09: 1ffffffff203a81a R10: dffffc0000000000 R11: fffffbfff203a81b R12: 000000001e40456c R13: ffff88807b3e8000 R14: 00000000b48d40fd R15: 00000000000000a3 FS: 00005555834a9500(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fffbfcbde50 CR3: 000000001ee68000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623 do_write_seqcount_begin_nested include/linux/seqlock.h:519 [inline] do_write_seqcount_begin include/linux/seqlock.h:545 [inline] vtime_user_exit+0x95/0x3e0 kernel/sched/cputime.c:725 __context_tracking_exit+0x4c/0x80 kernel/context_tracking.c:160 user_exit_irqoff include/linux/context_tracking.h:47 [inline] __enter_from_user_mode kernel/entry/common.c:22 [inline] syscall_enter_from_user_mode+0x56/0x70 kernel/entry/common.c:110 do_syscall_64+0x24/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f045f833997 Code: 48 89 fa 4c 89 df e8 a8 56 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff RSP: 002b:00007ffdc647b880 EFLAGS: 00000202 ORIG_RAX: 00000000000000e6 RAX: ffffffffffffffda RBX: 00005555834a9500 RCX: 00007f045f833997 RDX: 00007ffdc647b8c0 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007ffdc647bda0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000004 R13: 00007ffdc647b8fc R14: 00007ffdc647b990 R15: 0000000000000000