INFO: task syz.3.268:8109 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.268 state:D stack:25592 pid:8109 tgid:8108 ppid:7770 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5387 [inline] __schedule+0x1681/0x54c0 kernel/sched/core.c:7188 __schedule_loop kernel/sched/core.c:7267 [inline] rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7563 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1659 [inline] __rt_mutex_slowlock kernel/locking/rtmutex.c:1736 [inline] __rt_mutex_slowlock_locked+0x1f8f/0x25c0 kernel/locking/rtmutex.c:1776 __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:1496 [inline] down_read+0x132/0x200 kernel/locking/rwsem.c:1570 __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+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f6d39bcc819 RSP: 002b:00007f6d37e1e028 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3 RAX: ffffffffffffffda RBX: 00007f6d39e45fa0 RCX: 00007f6d39bcc819 RDX: 0000000000000000 RSI: 0000200000000040 RDI: ffffffff80000800 RBP: 00007f6d39c62c91 R08: 0000000000000000 R09: 0000000000000000 R10: 000020000001fb40 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f6d39e46038 R14: 00007f6d39e45fa0 R15: 00007ffc721becf8 Showing all locks held in the system: 5 locks held by kworker/0:1/10: 4 locks held by pr/legacy/17: 1 lock held by khungtaskd/38: #0: ffffffff8dfc7ec0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8dfc7ec0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #0: ffffffff8dfc7ec0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 8 locks held by kworker/u8:3/56: 5 locks held by kworker/1:2/808: 1 lock held by udevd/5166: #0: ffffffff8dc1cb98 (inode_hash_lock){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline] #0: ffffffff8dc1cb98 (inode_hash_lock){+.+.}-{3:3}, at: __remove_inode_hash fs/inode.c:709 [inline] #0: ffffffff8dc1cb98 (inode_hash_lock){+.+.}-{3:3}, at: remove_inode_hash include/linux/fs.h:3047 [inline] #0: ffffffff8dc1cb98 (inode_hash_lock){+.+.}-{3:3}, at: evict+0x6f8/0xb10 fs/inode.c:849 2 locks held by getty/5550: #0: ffff8880287f80a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003cbe2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13a0 drivers/tty/n_tty.c:2211 4 locks held by syz-executor/5797: 1 lock held by syz.3.268/8109: #0: ffff8880315080d0 (&type->s_umount_key#84){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline] #0: ffff8880315080d0 (&type->s_umount_key#84){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122 2 locks held by kworker/u8:13/8143: 3 locks held by udevd/8210: 2 locks held by udevd/8224: #0: ffff888022a81680 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:1044 [inline] #0: ffff888022a81680 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: blkdev_read_iter+0x2ff/0x440 block/fops.c:854 #1: ffff888022a81850 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:1094 [inline] #1: ffff888022a81850 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_update_page mm/filemap.c:2554 [inline] #1: ffff888022a81850 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_get_pages+0x931/0x1e70 mm/filemap.c:2718 2 locks held by syz-executor/8233: 4 locks held by syz.6.548/9888: 6 locks held by syz.8.547/9890: 2 locks held by syz.8.547/9906: #0: ffff88806531e480 (sb_writers#19){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493 #1: ffff88804d1e6110 (&inode->i_sb->s_type->i_mutex_dir_key/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1074 [inline] #1: ffff88804d1e6110 (&inode->i_sb->s_type->i_mutex_dir_key/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2914 [inline] #1: ffff88804d1e6110 (&inode->i_sb->s_type->i_mutex_dir_key/1){+.+.}-{4:4}, at: start_dirop fs/namei.c:2938 [inline] #1: ffff88804d1e6110 (&inode->i_sb->s_type->i_mutex_dir_key/1){+.+.}-{4:4}, at: filename_create+0x200/0x370 fs/namei.c:4950 6 locks held by syz.9.549/9892: 1 lock held by dhcpcd/9905: #0: ffff88807669a358 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1713 [inline] #0: ffff88807669a358 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x33/0xe10 net/packet/af_packet.c:3199 3 locks held by syz.7.550/9908: ============================================= 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 03/18/2026 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+0xfaa/0x1000 kernel/hung_task.c:515 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 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: 56 Comm: kworker/u8:3 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 Workqueue: events_unbound nsim_dev_trap_report_work RIP: 0010:_find_first_zero_bit+0x99/0xb0 lib/find_bit.c:149 Code: 08 45 31 ed 4d 89 f7 eb 11 49 8b 06 49 83 c7 08 49 83 c6 08 48 83 f8 ff 75 bb 49 83 c5 40 49 39 dd 73 c8 4c 89 f8 48 c1 e8 03 <42> 80 3c 20 00 74 d8 4c 89 ff e8 c8 6d 8e fd eb ce 66 0f 1f 44 00 RSP: 0018:ffffc9000122ec30 EFLAGS: 00000802 RAX: 1ffffffff266417f RBX: 0000000000100000 RCX: 0000000000000001 RDX: 00000000f997e601 RSI: 0000000000100000 RDI: ffffffff9331b470 RBP: adbd84ec3f7b4dff R08: ffffffff81b083c9 R09: ffff8880b8928518 R10: dffffc0000000000 R11: fffffbfff1f16397 R12: dffffc0000000000 R13: 000000000002bc40 R14: ffffffff93320bf8 R15: ffffffff93320bf8 FS: 0000000000000000(0000) GS:ffff888126221000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f1d931e7000 CR3: 000000003906c000 CR4: 00000000003526f0 Call Trace: find_first_zero_bit include/linux/find.h:391 [inline] alloc_lock_chain kernel/locking/lockdep.c:3714 [inline] add_chain_cache kernel/locking/lockdep.c:3746 [inline] lookup_chain_cache_add kernel/locking/lockdep.c:3855 [inline] validate_chain kernel/locking/lockdep.c:3876 [inline] __lock_acquire+0xb80/0x2cf0 kernel/locking/lockdep.c:5237 lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868 __raw_spin_lock include/linux/spinlock_api_smp.h:158 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:158 class_raw_spinlock_constructor include/linux/spinlock.h:535 [inline] __hrtimer_rearm_deferred+0x99/0x460 kernel/time/hrtimer.c:2051 hrtimer_rearm_deferred_tif include/linux/hrtimer_rearm.h:53 [inline] hrtimer_rearm_deferred include/linux/hrtimer_rearm.h:62 [inline] irqentry_exit_to_kernel_mode_after_preempt include/linux/irq-entry-common.h:513 [inline] irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:550 [inline] irqentry_exit+0x6a0/0x730 kernel/entry/common.c:164 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:__preempt_count_add kernel/rcu/tree.c:748 [inline] RIP: 0010:rcu_is_watching+0x6/0xb0 kernel/rcu/tree.c:751 Code: e8 5f 7d 30 03 eb cc 66 66 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 41 57 <41> 56 53 65 ff 05 50 0c c7 10 e8 7b bc 7d 09 89 c3 83 f8 08 73 65 RSP: 0018:ffffc9000122efa8 EFLAGS: 00000297 RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0000000000000002 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8dfc7ec0 RBP: ffffffff81765576 R08: 0000000000000000 R09: 0000000000000000 R10: ffffc9000122f178 R11: ffffffff81aef0c0 R12: 0000000000000002 R13: ffffffff8dfc7ec0 R14: 0000000000000000 R15: 0000000000000000 trace_lock_acquire include/trace/events/lock.h:24 [inline] lock_acquire+0x5f/0x350 kernel/locking/lockdep.c:5831 rcu_lock_acquire include/linux/rcupdate.h:300 [inline] rcu_read_lock include/linux/rcupdate.h:838 [inline] class_rcu_constructor include/linux/rcupdate.h:1181 [inline] unwind_next_frame+0xc3/0x2550 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 unpoison_slab_object mm/kasan/common.c:340 [inline] __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:366 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4569 [inline] slab_alloc_node mm/slub.c:4898 [inline] kmem_cache_alloc_noprof+0x33b/0x680 mm/slub.c:4905 kmem_alloc_batch lib/debugobjects.c:371 [inline] fill_pool+0x156/0x580 lib/debugobjects.c:420 debug_objects_fill_pool+0x97/0xd0 lib/debugobjects.c:742 debug_object_activate+0x36/0x520 lib/debugobjects.c:831 debug_rcu_head_queue kernel/rcu/rcu.h:236 [inline] __call_rcu_common kernel/rcu/tree.c:3116 [inline] call_rcu+0x43/0x890 kernel/rcu/tree.c:3251 slab_free_hook mm/slub.c:2653 [inline] slab_free mm/slub.c:6246 [inline] kmem_cache_free+0x526/0x6c0 mm/slub.c:6373 mempool_free+0xf5/0x140 mm/mempool.c:711 blk_update_request+0x57e/0xe60 block/blk-mq.c:1016 blk_mq_end_request+0x3e/0x70 block/blk-mq.c:1178 blk_complete_reqs block/blk-mq.c:1253 [inline] blk_done_softirq+0x10a/0x160 block/blk-mq.c:1258 handle_softirqs+0x1de/0x6d0 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] __local_bh_enable_ip+0x170/0x2b0 kernel/softirq.c:302 local_bh_enable include/linux/bottom_half.h:33 [inline] __alloc_skb+0x1aa/0x7d0 net/core/skbuff.c:697 alloc_skb include/linux/skbuff.h:1383 [inline] nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:819 [inline] nsim_dev_trap_report drivers/net/netdevsim/dev.c:876 [inline] nsim_dev_trap_report_work+0x29f/0xbc0 drivers/net/netdevsim/dev.c:922 process_one_work kernel/workqueue.c:3302 [inline] process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3385 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3466 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245