INFO: task syz.0.59:6257 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.59 state:D stack:28152 pid:6257 tgid:6242 ppid:5808 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 rt_mutex_slowlock+0xbd/0x170 kernel/locking/rtmutex.c:1800 __rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline] rwbase_write_lock+0x14d/0x730 kernel/locking/rwbase_rt.c:244 inode_lock include/linux/fs.h:1028 [inline][ 276.361851][ T38] ntfs_fallocate+0x2e7/0x1230 ntfs_fallocate+0x2e7/0x1 fs/ntfs3/file.c:489[ 276.361851][ T38] ntfs_fallocate+0x2e7/0x1230 vfs_fallocate+0x672/0x7f0 fs/open.c:340 ioctl_preallocate fs/ioctl.c:289 [inline] file_ioctl+0x64b/0x870 fs/ioctl.c:332 do_vfs_ioctl+0xc29/0x1540 fs/ioctl.c:576 __do_sys_ioctl fs/ioctl.c:595 [inline] __se_sys_ioctl+0x82/0x170 fs/ioctl.c:583 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: 0033:0x7fd5d6d7c819 RSP: 002b:00007fd5d4fb5028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fd5d6ff6090 RCX: 00007fd5d6d7c819 RDX: 0000200000000000 RSI: 0000000040305829 RDI: 0000000000000008 RBP: 00007fd5d6e12c91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fd5d6ff6128 R14: 00007fd5d6ff6090 R15: 00007ffda4a114e8 INFO: task syz.0.59:6258 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.59 state:D stack:29024 pid:6258 tgid:6242 ppid:5808 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 rt_mutex_slowlock+0xbd/0x170 kernel/locking/rtmutex.c:1800 __rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline] rwbase_write_lock+0x14d/0x730 kernel/locking/rwbase_rt.c:244 inode_lock include/linux/fs.h:1028 [inline] ntfs_fallocate+0x2e7/0x1230 fs/ntfs3/file.c:489 vfs_fallocate+0x672/0x7f0 fs/open.c:340 ksys_fallocate fs/open.c:364 [inline] __do_sys_fallocate fs/open.c:369 [inline] __se_sys_fallocate fs/open.c:367 [inline] __x64_sys_fallocate+0xc0/0x110 fs/open.c:367 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: 0033:0x7fd5d6d7c819 RSP: 002b:00007fd5d4f94028 EFLAGS: 00000246 ORIG_RAX: 000000000000011d RAX: ffffffffffffffda RBX: 00007fd5d6ff6180 RCX: 00007fd5d6d7c819 RDX: 0000000000000000 RSI: 0000000000000020 RDI: 0000000000000007 RBP: 00007fd5d6e12c91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000008000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fd5d6ff6218 R14: 00007fd5d6ff6180 R15: 00007ffda4a114e8 Showing all locks held in the system: 3 locks held by kworker/u8:0/12: #0: ffff888019c44138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #0: ffff888019c44138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3359 #1: ffffc90000117c40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3252 [inline] #1: ffffc90000117c40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3359 #2: ffffffff8f15cb38 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:313 3 locks held by ksoftirqd/0/15: 4 locks held by pr/legacy/17: 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 5 locks held by kworker/u8:2/41: 4 locks held by kworker/u8:11/3484: #0: ffff88801aee1138 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #0: ffff88801aee1138 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3359 #1: ffffc9000eb07c40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3252 [inline] #1: ffffc9000eb07c40 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3359 #2: ffffffff8f14e380 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf4/0x800 net/core/net_namespace.c:675 #3: ffffffff8f15cb38 (rtnl_mutex){+.+.}-{4:4}, at: wg_destruct+0x25/0x310 drivers/net/wireguard/device.c:246 6 locks held by kworker/u8:13/3560: #0: ffff888019c44138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #0: ffff888019c44138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3359 #1: ffffc9000ee87c40 ((work_completion)(&(&nsim_dev->trap_data->trap_report_dw)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3252 [inline] #1: ffffc9000ee87c40 ((work_completion)(&(&nsim_dev->trap_data->trap_report_dw)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3359 #2: ffff888033aa8300 (&devlink->lock_key#11){+.+.}-{4:4}, at: nsim_dev_trap_report_work+0x57/0xbc0 drivers/net/netdevsim/dev.c:909 #3: ffff888061fe8d20 (&nsim_trap_data->trap_lock){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline] #3: ffff888061fe8d20 (&nsim_trap_data->trap_lock){+.+.}-{3:3}, at: nsim_dev_trap_report drivers/net/netdevsim/dev.c:862 [inline] #3: ffff888061fe8d20 (&nsim_trap_data->trap_lock){+.+.}-{3:3}, at: nsim_dev_trap_report_work+0x1ad/0xbc0 drivers/net/netdevsim/dev.c:922 #4: ffffffff8ddcb9c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #4: ffffffff8ddcb9c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #4: ffffffff8ddcb9c0 (rcu_read_lock){....}-{1:3}, at: __rt_spin_lock kernel/locking/spinlock_rt.c:50 [inline] #4: ffffffff8ddcb9c0 (rcu_read_lock){....}-{1:3}, at: rt_spin_lock+0x1e0/0x400 kernel/locking/spinlock_rt.c:57 #5: ffff88801d699958 (&n->list_lock){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline] #5: ffff88801d699958 (&n->list_lock){+.+.}-{3:3}, at: get_partial_node_bulk mm/slub.c:3750 [inline] #5: ffff88801d699958 (&n->list_lock){+.+.}-{3:3}, at: __refill_objects_node+0x87/0x560 mm/slub.c:7027 3 locks held by kworker/u8:14/4828: #0: ffff8880320fc138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #0: ffff8880320fc138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3359 #1: ffffc90010ff7c40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3252 [inline] #1: ffffc90010ff7c40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3359 #2: ffffffff8f15cb38 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff8f15cb38 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x124/0x1680 net/ipv6/addrconf.c:4198 1 lock held by udevd/5165: 2 locks held by dhcpcd/5459: #0: ffffffff8f1cb0a0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffffffff8f15cb38 (rtnl_mutex){+.+.}-{4:4}, at: nl80211_pre_doit+0x5f/0x930 net/wireless/nl80211.c:18061 2 locks held by getty/5553: #0: ffff88803740d0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003e832e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13c0 drivers/tty/n_tty.c:2211 1 lock held by udevd/5786: 3 locks held by syz.0.59/6243: 2 locks held by syz.0.59/6257: #0: ffff888031f4a480 (sb_writers#12){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2710 [inline] #0: ffff888031f4a480 (sb_writers#12){.+.+}-{0:0}, at: vfs_fallocate+0x5f9/0x7f0 fs/open.c:339 #1: ffff888062f783b0 (&sb->s_type->i_mutex_key#24){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1028 [inline] #1: ffff888062f783b0 (&sb->s_type->i_mutex_key#24){+.+.}-{4:4}, at: ntfs_fallocate+0x2e7/0x1230 fs/ntfs3/file.c:489 2 locks held by syz.0.59/6258: #0: ffff888031f4a480 (sb_writers#12){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2710 [inline] #0: ffff888031f4a480 (sb_writers#12){.+.+}-{0:0}, at: vfs_fallocate+0x5f9/0x7f0 fs/open.c:339 #1: ffff888062f783b0 (&sb->s_type->i_mutex_key#24){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1028 [inline] #1: ffff888062f783b0 (&sb->s_type->i_mutex_key#24){+.+.}-{4:4}, at: ntfs_fallocate+0x2e7/0x1230 fs/ntfs3/file.c:489 1 lock held by syz-executor/6354: 1 lock held by syz-executor/6494: 2 locks held by syz-executor/7067: 3 locks held by syz-executor/7475: #0: ffffffff8e8b80e8 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8e8b80e8 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8e8b80e8 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570 #1: ffffffff8f15cb38 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8f15cb38 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #1: ffffffff8f15cb38 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8a1/0x1be0 net/core/rtnetlink.c:4093 #2: ffff88801d699958 (&n->list_lock){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline] #2: ffff88801d699958 (&n->list_lock){+.+.}-{3:3}, at: get_partial_node_bulk mm/slub.c:3750 [inline] #2: ffff88801d699958 (&n->list_lock){+.+.}-{3:3}, at: __refill_objects_node+0x87/0x560 mm/slub.c:7027 1 lock held by syz.7.238/7629: #0: ffff8880400800d0 (&type->s_umount_key#58/1){+.+.}-{4:4}, at: alloc_super+0x28c/0xac0 fs/super.c:345 ============================================= 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+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: 17 Comm: pr/legacy Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 RIP: 0010:io_serial_in+0x77/0xc0 drivers/tty/serial/8250/8250_port.c:401 Code: e8 9e 27 94 fc 44 89 f9 d3 e3 49 83 ee 80 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 9f 49 fa fc 41 03 1e 89 da ec <0f> b6 c0 5b 41 5c 41 5e 41 5f e9 9a 29 f7 05 cc 44 89 f9 80 e1 07 RSP: 0018:ffffc900001679d0 EFLAGS: 00000202 RAX: 1ffffffff332b300 RBX: 00000000000003fd RCX: 0000000000000000 RDX: 00000000000003fd RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffffff99959cd0 R08: 0000000000000000 R09: 0000000000000000 R10: dffffc0000000000 R11: ffffffff85305880 R12: dffffc0000000000 R13: 0000000000000000 R14: ffffffff99959a40 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888126436000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fb30d5a9000 CR3: 000000003531e000 CR4: 00000000003526f0 Call Trace: serial_in drivers/tty/serial/8250/8250.h:128 [inline] serial_lsr_in drivers/tty/serial/8250/8250.h:150 [inline] wait_for_lsr+0x1aa/0x2f0 drivers/tty/serial/8250/8250_port.c:1970 serial8250_fifo_wait_for_lsr_thre drivers/tty/serial/8250/8250_port.c:3207 [inline] serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3272 [inline] serial8250_console_write+0x120d/0x1b90 drivers/tty/serial/8250/8250_port.c:3357 console_emit_next_record kernel/printk/printk.c:3163 [inline] console_flush_one_record+0x68b/0xb90 kernel/printk/printk.c:3269 legacy_kthread_func+0x1b6/0x250 kernel/printk/printk.c:3712 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