INFO: task syz.0.547:8172 blocked for more than 143 seconds. Not tainted 6.12.0-rc2-next-20241010-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.547 state:D stack:25776 pid:8172 tgid:8171 ppid:7541 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5322 [inline] __schedule+0x1895/0x4b30 kernel/sched/core.c:6682 __schedule_loop kernel/sched/core.c:6759 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6774 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6831 rwsem_down_read_slowpath kernel/locking/rwsem.c:1084 [inline] __down_read_common kernel/locking/rwsem.c:1248 [inline] __down_read kernel/locking/rwsem.c:1261 [inline] down_read+0x705/0xa40 kernel/locking/rwsem.c:1526 __super_lock fs/super.c:58 [inline] super_lock+0x27c/0x400 fs/super.c:120 user_get_super+0xd2/0x180 fs/super.c:1000 quotactl_block fs/quota/quota.c:890 [inline] __do_sys_quotactl fs/quota/quota.c:955 [inline] __se_sys_quotactl+0x527/0xa30 fs/quota/quota.c:917 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f22bd77dff9 RSP: 002b:00007f22be598038 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3 RAX: ffffffffffffffda RBX: 00007f22bd935f80 RCX: 00007f22bd77dff9 RDX: 0000000000000000 RSI: 00000000200000c0 RDI: ffffffff80000801 RBP: 00007f22bd7f0296 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000020000100 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f22bd935f80 R15: 00007ffc03b41e48 Showing all locks held in the system: 3 locks held by kworker/0:0/8: 1 lock held by khungtaskd/30: #0: ffffffff8e939e20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff8e939e20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8e939e20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6720 3 locks held by kworker/u8:6/2563: #0: ffff88801ac89148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff88801ac89148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310 #1: ffffc90009257d00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc90009257d00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310 #2: ffffffff8fcd9ac8 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:276 3 locks held by kworker/u8:7/2914: #0: ffff88814b89f948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff88814b89f948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310 #1: ffffc900098a7d00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc900098a7d00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310 #2: ffffffff8fcd9ac8 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xd0/0x16f0 net/ipv6/addrconf.c:4196 1 lock held by dhcpcd/4903: #0: ffffffff8fcd9ac8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline] #0: ffffffff8fcd9ac8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x6e6/0xcf0 net/core/rtnetlink.c:6717 2 locks held by getty/5002: #0: ffff88814bb6b0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90002f062f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6a6/0x1e00 drivers/tty/n_tty.c:2211 3 locks held by kworker/1:8/5325: #0: ffff88801ac80948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff88801ac80948 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310 #1: ffffc90004247d00 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc90004247d00 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310 #2: ffff88806bece240 (&data->fib_lock){+.+.}-{3:3}, at: nsim_fib_event_work+0x2d1/0x4130 drivers/net/netdevsim/fib.c:1488 5 locks held by kworker/u8:8/5401: 1 lock held by syz-executor/6478: #0: ffff88807b7860e0 (&type->s_umount_key#94){++++}-{3:3}, at: __super_lock fs/super.c:56 [inline] #0: ffff88807b7860e0 (&type->s_umount_key#94){++++}-{3:3}, at: __super_lock_excl fs/super.c:71 [inline] #0: ffff88807b7860e0 (&type->s_umount_key#94){++++}-{3:3}, at: deactivate_super+0xb5/0xf0 fs/super.c:505 1 lock held by syz.0.547/8172: #0: ffff88807b7860e0 (&type->s_umount_key#94){++++}-{3:3}, at: __super_lock fs/super.c:58 [inline] #0: ffff88807b7860e0 (&type->s_umount_key#94){++++}-{3:3}, at: super_lock+0x27c/0x400 fs/super.c:120 2 locks held by syz-executor/10614: #0: ffff8880b863e898 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xb0/0x140 kernel/sched/core.c:601 #1: ffffffff8e614810 (mount_lock){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline] #1: ffffffff8e614810 (mount_lock){+.+.}-{2:2}, at: write_seqlock include/linux/seqlock.h:807 [inline] #1: ffffffff8e614810 (mount_lock){+.+.}-{2:2}, at: lock_mount_hash fs/namespace.c:214 [inline] #1: ffffffff8e614810 (mount_lock){+.+.}-{2:2}, at: drop_collected_mounts fs/namespace.c:2222 [inline] #1: ffffffff8e614810 (mount_lock){+.+.}-{2:2}, at: put_mnt_ns+0x81/0x120 fs/namespace.c:5553 1 lock held by syz.0.1072/10887: #0: ffffffff8e93f3b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:329 [inline] #0: ffffffff8e93f3b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x451/0x830 kernel/rcu/tree_exp.h:976 4 locks held by dhcpcd/10889: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.12.0-rc2-next-20241010-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 nmi_cpu_backtrace+0x49c/0x4d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:223 [inline] watchdog+0xff4/0x1040 kernel/hung_task.c:379 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 11 Comm: kworker/u8:0 Not tainted 6.12.0-rc2-next-20241010-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Workqueue: ipv6_addrconf addrconf_dad_work RIP: 0010:lookup_chain_cache kernel/locking/lockdep.c:3797 [inline] RIP: 0010:lookup_chain_cache_add kernel/locking/lockdep.c:3817 [inline] RIP: 0010:validate_chain+0x1b9/0x5920 kernel/locking/lockdep.c:3872 Code: b8 eb 83 b5 80 46 86 c8 61 49 0f af c6 48 c1 e8 2d 48 8d 1c c5 40 f7 e4 93 48 89 d8 48 c1 e8 03 48 89 44 24 68 42 80 3c 20 00 <74> 08 48 89 df e8 9d a5 8d 00 48 89 5c 24 48 48 8b 1b 48 85 db 74 RSP: 0018:ffffc90000107200 EFLAGS: 00000046 RAX: 1ffffffff27d7a8e RBX: ffffffff93ebd470 RCX: ffffffff81710c0e RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff942df800 RBP: ffffc90000107500 R08: ffffffff942df807 R09: 1ffffffff285bf00 R10: dffffc0000000000 R11: fffffbfff285bf01 R12: dffffc0000000000 R13: ffff88801befc7a0 R14: b833837b6a9e05d2 R15: ffff88801befc7a0 FS: 0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f7d3286f068 CR3: 000000000e736000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000097 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __lock_acquire+0x1384/0x2050 kernel/locking/lockdep.c:5202 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825 local_lock_acquire include/linux/local_lock_internal.h:29 [inline] get_random_u32+0x1c0/0xab0 drivers/char/random.c:553 __get_random_u32_below+0x14/0x90 drivers/char/random.c:567 get_random_u32_below include/linux/random.h:63 [inline] mld_dad_start_work net/ipv6/mcast.c:1089 [inline] ipv6_mc_dad_complete+0x284/0x490 net/ipv6/mcast.c:2248 addrconf_dad_completed+0x712/0xcd0 net/ipv6/addrconf.c:4342 addrconf_dad_work+0xdc2/0x16f0 process_one_work kernel/workqueue.c:3229 [inline] process_scheduled_works+0xa63/0x1850 kernel/workqueue.c:3310 worker_thread+0x870/0xd30 kernel/workqueue.c:3391 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244