INFO: task syz.6.23:7132 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.6.23 state:D stack:26088 pid:7132 tgid:7130 ppid:7089 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5396 [inline] __schedule+0x16f9/0x5500 kernel/sched/core.c:7197 __schedule_loop kernel/sched/core.c:7276 [inline] rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7572 rt_mutex_slowlock_block+0x508/0x680 kernel/locking/rtmutex.c:1667 __rt_mutex_slowlock kernel/locking/rtmutex.c:1744 [inline] __rt_mutex_slowlock_locked kernel/locking/rtmutex.c:1784 [inline] rt_mutex_slowlock+0x2dc/0x780 kernel/locking/rtmutex.c:1824 __rt_mutex_lock kernel/locking/rtmutex.c:1839 [inline] __mutex_lock_common kernel/locking/rtmutex_api.c:541 [inline] mutex_lock_nested+0x168/0x1d0 kernel/locking/rtmutex_api.c:559 blk_debugfs_lock_nomemsave block/blk.h:758 [inline] blk_trace_remove kernel/trace/blktrace.c:561 [inline] blk_trace_ioctl+0x39a/0x920 kernel/trace/blktrace.c:952 blkdev_common_ioctl+0x13a7/0x3240 block/ioctl.c:717 blkdev_ioctl+0x52b/0x750 block/ioctl.c:791 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl+0xff/0x170 fs/ioctl.c:583 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: 0033:0x7faec8a1c819 RSP: 002b:00007faec8055028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007faec8c96090 RCX: 00007faec8a1c819 RDX: 0000000000000000 RSI: 0000000000001276 RDI: 0000000000000003 RBP: 00007faec8ab2c91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007faec8c96128 R14: 00007faec8c96090 R15: 00007ffc1a15e4f8 Showing all locks held in the system: 4 locks held by kworker/u8:1/13: #0: ffff88801b6d6138 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x897/0x1630 kernel/workqueue.c:3281 #1: ffffc90000127c40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x8be/0x1630 kernel/workqueue.c:3282 #2: ffffffff8f583300 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf4/0x800 net/core/net_namespace.c:673 #3: ffffffff8f5927b8 (rtnl_mutex){+.+.}-{4:4}, at: ops_exit_rtnl_list net/core/net_namespace.c:173 [inline] #3: ffffffff8f5927b8 (rtnl_mutex){+.+.}-{4:4}, at: ops_undo_list+0x2a4/0x940 net/core/net_namespace.c:248 1 lock held by khungtaskd/38: #0: ffffffff8e1c8240 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8e1c8240 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #0: ffffffff8e1c8240 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6777 3 locks held by kworker/0:2/824: #0: ffff88813fe0f938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x897/0x1630 kernel/workqueue.c:3281 #1: ffffc9000541fc40 (deferred_process_work){+.+.}-{0:0}, at: process_one_work+0x8be/0x1630 kernel/workqueue.c:3282 #2: ffffffff8f5927b8 (rtnl_mutex){+.+.}-{4:4}, at: switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104 3 locks held by kworker/u8:15/1468: #0: ffff88813fe4c138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x897/0x1630 kernel/workqueue.c:3281 #1: ffffc90006a67c40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x8be/0x1630 kernel/workqueue.c:3282 #2: ffffffff8f5927b8 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:313 2 locks held by getty/5378: #0: ffff8880362b90a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003cb62e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13a0 drivers/tty/n_tty.c:2211 3 locks held by kworker/1:5/5935: #0: ffff88813fe0f938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x897/0x1630 kernel/workqueue.c:3281 #1: ffffc900039ffc40 (rx_mode_work){+.+.}-{0:0}, at: process_one_work+0x8be/0x1630 kernel/workqueue.c:3282 #2: ffffffff8f5927b8 (rtnl_mutex){+.+.}-{4:4}, at: netdev_rx_mode_work+0x1c/0x460 net/core/dev_addr_lists.c:1312 3 locks held by syz.6.23/7131: #0: ffff8880267cf878 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock_nomemsave block/blk.h:758 [inline] #0: ffff8880267cf878 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock block/blk.h:770 [inline] #0: ffff8880267cf878 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_setup+0x2d3/0x520 kernel/trace/blktrace.c:788 #1: ffffffff8e228bb8 (relay_channels_mutex){+.+.}-{4:4}, at: relay_open+0x3b8/0x920 kernel/relay.c:515 #2: ffffffff8e1c8240 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #2: ffffffff8e1c8240 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #2: ffffffff8e1c8240 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1181 [inline] #2: ffffffff8e1c8240 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0xa6/0x2550 arch/x86/kernel/unwind_orc.c:495 1 lock held by syz.6.23/7132: #0: ffff8880267cf878 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock_nomemsave block/blk.h:758 [inline] #0: ffff8880267cf878 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_remove kernel/trace/blktrace.c:561 [inline] #0: ffff8880267cf878 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_ioctl+0x39a/0x920 kernel/trace/blktrace.c:952 1 lock held by syz.7.24/7308: #0: ffff8880267cf878 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock_nomemsave block/blk.h:758 [inline] #0: ffff8880267cf878 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock block/blk.h:770 [inline] #0: ffff8880267cf878 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_setup+0x2d3/0x520 kernel/trace/blktrace.c:788 1 lock held by syz.7.24/7309: #0: ffff8880267cf878 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock_nomemsave block/blk.h:758 [inline] #0: ffff8880267cf878 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_remove kernel/trace/blktrace.c:561 [inline] #0: ffff8880267cf878 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_ioctl+0x39a/0x920 kernel/trace/blktrace.c:952 1 lock held by syz.8.25/7355: #0: ffff8880267cf878 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock_nomemsave block/blk.h:758 [inline] #0: ffff8880267cf878 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock block/blk.h:770 [inline] #0: ffff8880267cf878 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_setup+0x2d3/0x520 kernel/trace/blktrace.c:788 1 lock held by syz.8.25/7356: #0: ffff8880267cf878 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock_nomemsave block/blk.h:758 [inline] #0: ffff8880267cf878 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_remove kernel/trace/blktrace.c:561 [inline] #0: ffff8880267cf878 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_ioctl+0x39a/0x920 kernel/trace/blktrace.c:952 1 lock held by syz.9.26/7479: #0: ffff8880267cf878 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock_nomemsave block/blk.h:758 [inline] #0: ffff8880267cf878 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock block/blk.h:770 [inline] #0: ffff8880267cf878 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_setup+0x2d3/0x520 kernel/trace/blktrace.c:788 1 lock held by syz.9.26/7481: #0: ffff8880267cf878 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock_nomemsave block/blk.h:758 [inline] #0: ffff8880267cf878 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_remove kernel/trace/blktrace.c:561 [inline] #0: ffff8880267cf878 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_ioctl+0x39a/0x920 kernel/trace/blktrace.c:952 1 lock held by syz.0.27/7673: #0: ffff8880267cf878 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock_nomemsave block/blk.h:758 [inline] #0: ffff8880267cf878 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock block/blk.h:770 [inline] #0: ffff8880267cf878 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_setup+0x2d3/0x520 kernel/trace/blktrace.c:788 1 lock held by syz.0.27/7675: #0: ffff8880267cf878 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock_nomemsave block/blk.h:758 [inline] #0: ffff8880267cf878 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_remove kernel/trace/blktrace.c:561 [inline] #0: ffff8880267cf878 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_ioctl+0x39a/0x920 kernel/trace/blktrace.c:952 1 lock held by syz.1.28/7962: #0: ffff8880267cf878 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock_nomemsave block/blk.h:758 [inline] #0: ffff8880267cf878 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock block/blk.h:770 [inline] #0: ffff8880267cf878 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_setup+0x2d3/0x520 kernel/trace/blktrace.c:788 1 lock held by syz.1.28/7966: #0: ffff8880267cf878 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock_nomemsave block/blk.h:758 [inline] #0: ffff8880267cf878 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_remove kernel/trace/blktrace.c:561 [inline] #0: ffff8880267cf878 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_ioctl+0x39a/0x920 kernel/trace/blktrace.c:952 1 lock held by syz.2.29/8227: #0: ffff8880267cf878 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock_nomemsave block/blk.h:758 [inline] #0: ffff8880267cf878 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock block/blk.h:770 [inline] #0: ffff8880267cf878 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_setup+0x2d3/0x520 kernel/trace/blktrace.c:788 1 lock held by syz.2.29/8228: #0: ffff8880267cf878 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock_nomemsave block/blk.h:758 [inline] #0: ffff8880267cf878 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_remove kernel/trace/blktrace.c:561 [inline] #0: ffff8880267cf878 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_ioctl+0x39a/0x920 kernel/trace/blktrace.c:952 4 locks held by dhcpcd-run-hook/8306: #0: ffff8880651081c8 (vm_lock){++++}-{0:0}, at: lock_vma_under_rcu+0x1d1/0x500 mm/mmap_lock.c:310 #1: ffffffff8e1c8240 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #1: ffffffff8e1c8240 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #1: ffffffff8e1c8240 (rcu_read_lock){....}-{1:3}, at: __pte_offset_map+0x29/0x200 mm/pgtable-generic.c:290 #2: ffff888025318b98 (ptlock_ptr(ptdesc)#2){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline] #2: ffff888025318b98 (ptlock_ptr(ptdesc)#2){+.+.}-{3:3}, at: pte_offset_map_lock+0x13d/0x210 mm/pgtable-generic.c:404 #3: ffffffff8e1c8240 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #3: ffffffff8e1c8240 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #3: ffffffff8e1c8240 (rcu_read_lock){....}-{1:3}, at: __rt_spin_lock kernel/locking/spinlock_rt.c:50 [inline] #3: ffffffff8e1c8240 (rcu_read_lock){....}-{1:3}, at: rt_spin_lock+0x1e0/0x400 kernel/locking/spinlock_rt.c:57 ============================================= 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 04/18/2026 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:162 [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:353 [inline] watchdog+0xfd3/0x1030 kernel/hung_task.c:561 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: 8306 Comm: dhcpcd-run-hook Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 RIP: 0010:folio_test_slab include/linux/page-flags.h:1041 [inline] RIP: 0010:folio_objcg include/linux/memcontrol.h:396 [inline] RIP: 0010:folio_memcg include/linux/memcontrol.h:432 [inline] RIP: 0010:lruvec_stat_mod_folio+0xed/0x3e0 mm/memcontrol.c:984 Code: 00 00 48 c7 c2 20 7b 5c 8b e8 0f 1c 6f ff 49 8d 7c 24 38 48 89 f8 48 c1 e8 03 80 3c 28 00 74 05 e8 68 d2 fc ff 4d 8b 6c 24 38 <4d> 8d 74 24 30 4c 89 f0 48 c1 e8 03 0f b6 04 28 84 c0 0f 85 3a 02 RSP: 0000:ffffc90003a3fa28 EFLAGS: 00000246 RAX: 1ffffd400032f5b7 RBX: ffffffff8231e33e RCX: 0000000080000001 RDX: 00000000b48b6328 RSI: ffffffff8baa6cc0 RDI: ffffea000197adb8 RBP: dffffc0000000000 R08: ffffffff8231e33e R09: ffffffff8e1c8240 R10: dffffc0000000000 R11: fffff9400032f5b1 R12: ffffea000197ad80 R13: ffff88801bac1180 R14: 0000000000000001 R15: ffff88813fffac80 FS: 00007fcfbd275c80(0000) GS:ffff888125dc7000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fff400d0ed8 CR3: 000000003402e000 CR4: 00000000003526f0 Call Trace: __folio_mod_stat mm/rmap.c:1336 [inline] folio_add_new_anon_rmap+0x662/0xbf0 mm/rmap.c:1696 wp_page_copy mm/memory.c:3942 [inline] do_wp_page+0x2438/0x3d90 mm/memory.c:4336 handle_pte_fault mm/memory.c:6446 [inline] __handle_mm_fault mm/memory.c:6568 [inline] handle_mm_fault+0xaee/0x14c0 mm/memory.c:6737 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:595 RIP: 0033:0x7fcfbd414143 Code: 89 fc 55 89 d5 53 48 89 f3 48 81 ec 48 08 00 00 48 8b 05 28 ae 0f 00 64 48 8b 00 48 8b 00 83 b8 a0 00 00 00 01 75 40 48 89 df b8 1f f5 ff 89 e9 41 89 e8 48 89 de 48 81 c4 48 08 00 00 c1 e9 RSP: 002b:00007fff400d0ee0 EFLAGS: 00010246 RAX: 00007fcfbd50bde0 RBX: 00005567909a5fa0 RCX: 0000000000000002 RDX: 0000000000000000 RSI: 00005567909a5fa0 RDI: 00005567909a5fa0 RBP: 0000000000000000 R08: 00005567909a5fed R09: 3c00000040001201 R10: 0000000000000002 R11: 0000000000000001 R12: 00005567909a5fd8 R13: 00005567909a5fa0 R14: 00007fff400d1770 R15: 0000556790995c30