INFO: task syz.9.1323:17932 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.9.1323 state:D stack:26688 pid:17932 tgid:17929 ppid:16327 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5298 [inline] __schedule+0x1553/0x5240 kernel/sched/core.c:6911 __schedule_loop kernel/sched/core.c:6993 [inline] rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7289 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline] __rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline] __rt_mutex_slowlock_locked+0x1f8f/0x25c0 kernel/locking/rtmutex.c:1760 __rwbase_read_lock+0xc3/0x180 kernel/locking/rwbase_rt.c:114 rwbase_read_lock kernel/locking/rwbase_rt.c:147 [inline] __down_read kernel/locking/rwsem.c:1466 [inline] down_read+0x132/0x200 kernel/locking/rwsem.c:1539 __super_lock fs/super.c:60 [inline] super_lock+0x2d6/0x3d0 fs/super.c:122 user_get_super+0xc8/0x120 fs/super.c:1001 quotactl_block fs/quota/quota.c:889 [inline] __do_sys_quotactl fs/quota/quota.c:955 [inline] __se_sys_quotactl+0x540/0x9e0 fs/quota/quota.c:917 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f5e77c9c799 RSP: 002b:00007f5e75eee028 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3 RAX: ffffffffffffffda RBX: 00007f5e77f15fa0 RCX: 00007f5e77c9c799 RDX: 0000000000000000 RSI: 0000200000000040 RDI: ffffffff80000602 RBP: 00007f5e77d32c99 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f5e77f16038 R14: 00007f5e77f15fa0 R15: 00007fff06bdf488 Showing all locks held in the system: 1 lock held by khungtaskd/38: #0: ffffffff8ddcb9c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8ddcb9c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8ddcb9c0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 3 locks held by kworker/1:2/829: #0: ffff888019c07938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #0: ffff888019c07938 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3359 #1: ffffc90004aa7c40 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3252 [inline] #1: ffffc90004aa7c40 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3359 #2: ffff888060514260 (&data->fib_lock){+.+.}-{4:4}, at: nsim_fib_event_work+0x222/0x3e0 drivers/net/netdevsim/fib.c:1490 2 locks held by getty/5557: #0: ffff888037bf60a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003e8b2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13c0 drivers/tty/n_tty.c:2211 4 locks held by syz-executor/12549: 3 locks held by kworker/u8:9/15443: #0: ffff88803239b138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #0: ffff88803239b138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3359 #1: ffffc9000783fc40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3252 [inline] #1: ffffc9000783fc40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3359 #2: ffffffff8f15bc78 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff8f15bc78 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x124/0x1680 net/ipv6/addrconf.c:4198 3 locks held by kworker/1:1/15810: #0: ffff888019c07938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #0: ffff888019c07938 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3359 #1: ffffc900053c7c40 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3252 [inline] #1: ffffc900053c7c40 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3359 #2: ffff888076543260 (&data->fib_lock){+.+.}-{4:4}, at: nsim_fib_event_work+0x222/0x3e0 drivers/net/netdevsim/fib.c:1490 5 locks held by syz-executor/16263: 1 lock held by syz.9.1323/17932: #0: ffff88806812a0d0 (&type->s_umount_key#61){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline] #0: ffff88806812a0d0 (&type->s_umount_key#61){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122 1 lock held by syz.8.1466/19288: #0: ffff88806812a0d0 (&type->s_umount_key#61){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline] #0: ffff88806812a0d0 (&type->s_umount_key#61){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122 2 locks held by syz-executor/19454: #0: ffffffff8f1ca1e0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffffffff8f1c9fd8 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline] #1: ffffffff8f1c9fd8 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline] #1: ffffffff8f1c9fd8 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0 net/netlink/genetlink.c:1208 6 locks held by syz-executor/19547: 1 lock held by udevadm/20080: 2 locks held by syz.5.1543/20084: 4 locks held by dhcpcd-run-hook/20088: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 38 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 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+0xfd9/0x1030 kernel/hung_task.c:515 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158 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: 20084 Comm: syz.5.1543 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 RIP: 0010:rcu_lockdep_current_cpu_online+0x60/0x120 kernel/rcu/tree.c:4040 Code: 09 89 c3 83 f8 08 0f 83 c7 00 00 00 49 be 00 00 00 00 00 fc ff df 48 8d 1c dd 90 67 80 8d 48 89 d8 48 c1 e8 03 42 80 3c 30 00 <74> 08 48 89 df e8 16 d6 80 00 48 8b 03 48 8d 98 40 47 50 92 48 8d RSP: 0000:ffffc90004a07c28 EFLAGS: 00000246 RAX: 1ffffffff1b00cf3 RBX: ffffffff8d806798 RCX: 0000000080000001 RDX: 0000000000000000 RSI: ffffffff8ba66fe0 RDI: ffffffff8ba66fa0 RBP: 0000000000000017 R08: 0000000000000000 R09: 0000000000000000 R10: dffffc0000000000 R11: fffffbfff1ed4b77 R12: 1ffff1100665585e R13: ffff88807e761650 R14: dffffc0000000000 R15: dffffc0000000000 FS: 00007f2fcb5366c0(0000) GS:ffff888126438000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f2fc3422000 CR3: 0000000079fd2000 CR4: 00000000003526f0 Call Trace: rcu_read_lock_held_common kernel/rcu/update.c:113 [inline] rcu_read_lock_sched_held+0x1e/0x70 kernel/rcu/update.c:124 task_css include/linux/cgroup.h:460 [inline] mem_cgroup_from_task+0x4d/0x120 mm/memcontrol.c:903 count_memcg_events_mm include/linux/memcontrol.h:984 [inline] count_memcg_event_mm+0x12c/0x260 include/linux/memcontrol.h:993 mm_account_fault mm/memory.c:6489 [inline] handle_mm_fault+0x11d6/0x13c0 mm/memory.c:6650 do_user_addr_fault+0xa73/0x1340 arch/x86/mm/fault.c:1334 handle_page_fault arch/x86/mm/fault.c:1474 [inline] exc_page_fault+0x6a/0xc0 arch/x86/mm/fault.c:1527 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618 RIP: 0033:0x7f2fcd193b0e Code: c1 49 39 4f 08 72 54 8d 4d ff 85 ed 74 3b 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 48 39 f0 72 1b 4d 8b 07 49 89 c1 49 29 f1 <47> 0f b6 0c 08 45 84 c9 74 08 45 88 0c 00 49 8b 47 10 48 83 c0 01 RSP: 002b:00007f2fcb535470 EFLAGS: 00010206 RAX: 000000000034e001 RBX: 00007f2fcb535530 RCX: 0000000000000046 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 00007f2fcb5355d0 RBP: 0000000000000102 R08: 00007f2fc30d4000 R09: 000000000034e000 R10: 0000000000000000 R11: 00007f2fcb535540 R12: 0000000000000001 R13: 00007f2fcd392620 R14: 0000000000000000 R15: 00007f2fcb5355d0