INFO: task syz.2.65:6311 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.65 state:D stack:24576 pid:6311 tgid:6298 ppid:5803 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] vfs_fileattr_set+0x161/0xc90 fs/file_attr.c:281 ioctl_setflags+0x189/0x1f0 fs/file_attr.c:337 do_vfs_ioctl+0x9f4/0x1540 fs/ioctl.c:560 __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: 0033:0x7f71249dc799 RSP: 002b:00007f7122c15028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f7124c56090 RCX: 00007f71249dc799 RDX: 00002000000001c0 RSI: 0000000040086602 RDI: 0000000000000005 RBP: 00007f7124a72c99 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f7124c56128 R14: 00007f7124c56090 R15: 00007ffc657c6518 INFO: task syz.2.65:6315 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.65 state:D stack:28864 pid:6315 tgid:6298 ppid:5803 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 inode_lock_shared include/linux/fs.h:1043 [inline] lookup_slow+0x46/0x70 fs/namei.c:1932 walk_component fs/namei.c:2279 [inline] link_path_walk+0xd1e/0x18d0 fs/namei.c:2647 path_parentat fs/namei.c:2851 [inline] __filename_parentat+0x27f/0x6f0 fs/namei.c:2875 filename_parentat fs/namei.c:2893 [inline] filename_renameat2+0x1ef/0x9c0 fs/namei.c:6085 __do_sys_renameat2 fs/namei.c:6173 [inline] __se_sys_renameat2+0x5a/0x2c0 fs/namei.c:6168 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: 0033:0x7f71249dc799 RSP: 002b:00007f7122bf4028 EFLAGS: 00000246 ORIG_RAX: 000000000000013c RAX: ffffffffffffffda RBX: 00007f7124c56180 RCX: 00007f71249dc799 RDX: ffffffffffffff9c RSI: 0000200000000000 RDI: ffffffffffffff9c RBP: 00007f7124a72c99 R08: 0000000000000004 R09: 0000000000000000 R10: 0000200000000440 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f7124c56218 R14: 00007f7124c56180 R15: 00007ffc657c6518 Showing all locks held in the system: 1 lock held by khungtaskd/39: #0: ffffffff8ddcb980 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8ddcb980 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8ddcb980 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 4 locks held by kworker/u8:4/67: #0: ffff88801f2fd938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #0: ffff88801f2fd938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3359 #1: ffffc9000152fc40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3252 [inline] #1: ffffc9000152fc40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3359 #2: ffff888039fd00d0 (&type->s_umount_key#78){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:565 #3: ffff88804d16a8e8 (&jfs_ip->commit_mutex){+.+.}-{4:4}, at: jfs_commit_inode+0x1ca/0x530 fs/jfs/inode.c:108 6 locks held by kworker/u8:5/117: 8 locks held by kworker/u8:11/1380: 2 locks held by kworker/u8:12/1384: 2 locks held by kworker/u8:13/1392: 5 locks held by kworker/u8:14/1400: 4 locks held by kworker/u8:16/1451: 7 locks held by kworker/u8:17/1474: #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: ffffc9000661fc40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3252 [inline] #1: ffffc9000661fc40 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3359 #2: ffffffff8f14c400 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf4/0x800 net/core/net_namespace.c:675 #3: ffff888060d400d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline] #3: ffff888060d400d8 (&dev->mutex){....}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:108 [inline] #3: ffff888060d400d8 (&dev->mutex){....}-{4:4}, at: devlink_pernet_pre_exit+0x117/0x3f0 net/devlink/core.c:504 #4: ffff8880217f2300 (&devlink->lock_key#2){+.+.}-{4:4}, at: devl_lock net/devlink/core.c:274 [inline] #4: ffff8880217f2300 (&devlink->lock_key#2){+.+.}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:109 [inline] #4: ffff8880217f2300 (&devlink->lock_key#2){+.+.}-{4:4}, at: devlink_pernet_pre_exit+0x129/0x3f0 net/devlink/core.c:504 #5: ffffffff8f15abb8 (rtnl_mutex){+.+.}-{4:4}, at: nsim_destroy+0xed/0x680 drivers/net/netdevsim/netdev.c:1180 #6: ffff888060dd8ea0 (&dev_instance_lock_key#24){+.+.}-{4:4}, at: netdev_lock include/linux/netdevice.h:2785 [inline] #6: ffff888060dd8ea0 (&dev_instance_lock_key#24){+.+.}-{4:4}, at: netdev_lock_ops include/net/netdev_lock.h:42 [inline] #6: ffff888060dd8ea0 (&dev_instance_lock_key#24){+.+.}-{4:4}, at: unregister_netdevice_many_notify+0x118e/0x2360 net/core/dev.c:12401 4 locks held by kworker/u9:1/5119: #0: ffff888035bbf138 ((wq_completion)hci2#4){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #0: ffff888035bbf138 ((wq_completion)hci2#4){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3359 #1: ffffc900112f7c40 ((work_completion)(&hdev->rx_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3252 [inline] #1: ffffc900112f7c40 ((work_completion)(&hdev->rx_work)){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3359 #2: ffff88805ef380b0 (&hdev->lock){+.+.}-{4:4}, at: hci_conn_complete_evt+0xbb/0x11d0 net/bluetooth/hci_event.c:3113 #3: ffff888019c4f238 (&root->kernfs_rwsem){++++}-{4:4}, at: kernfs_add_one+0x41/0x5c0 fs/kernfs/dir.c:796 3 locks held by udevd/5169: 2 locks held by getty/5555: #0: ffff8880376710a0 (&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/5786: 3 locks held by syz-executor/5807: #0: ffff888026bde0d0 (&type->s_umount_key#69){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff888026bde0d0 (&type->s_umount_key#69){++++}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline] #0: ffff888026bde0d0 (&type->s_umount_key#69){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:508 #1: ffff888026bdeb08 (&s->s_sync_lock){+.+.}-{4:4}, at: wait_sb_inodes fs/fs-writeback.c:2739 [inline] #1: ffff888026bdeb08 (&s->s_sync_lock){+.+.}-{4:4}, at: sync_inodes_sb+0x288/0xc10 fs/fs-writeback.c:2927 #2: ffffffff8da1cd98 (&folio_wait_table[i]){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline] #2: ffffffff8da1cd98 (&folio_wait_table[i]){+.+.}-{3:3}, at: finish_wait+0xbe/0x1e0 kernel/sched/wait.c:394 2 locks held by udevd/5821: #0: ffff88802259c868 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:1043 [inline] #0: ffff88802259c868 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: blkdev_read_iter+0x2ff/0x440 block/fops.c:854 #1: ffff88802259ca38 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:1093 [inline] #1: ffff88802259ca38 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_update_page mm/filemap.c:2554 [inline] #1: ffff88802259ca38 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_get_pages+0x931/0x1ea0 mm/filemap.c:2718 4 locks held by syz.2.65/6299: 2 locks held by syz.2.65/6311: #0: ffff888039fd0480 (sb_writers#22){.+.+}-{0:0}, at: mnt_want_write_file+0x63/0x210 fs/namespace.c:537 #1: ffff88804d16acb8 (&type->i_mutex_dir_key#15){++++}-{4:4}, at: inode_lock include/linux/fs.h:1028 [inline] #1: ffff88804d16acb8 (&type->i_mutex_dir_key#15){++++}-{4:4}, at: vfs_fileattr_set+0x161/0xc90 fs/file_attr.c:281 1 lock held by syz.2.65/6315: #0: ffff88804d16acb8 (&type->i_mutex_dir_key#15){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:1043 [inline] #0: ffff88804d16acb8 (&type->i_mutex_dir_key#15){++++}-{4:4}, at: lookup_slow+0x46/0x70 fs/namei.c:1932 1 lock held by udevadm/8345: #0: ffff888019c4f238 (&root->kernfs_rwsem){++++}-{4:4}, at: kernfs_dop_revalidate+0x9e/0x5e0 fs/kernfs/dir.c:1185 3 locks held by syz.6.329/8354: ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 39 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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 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 02/12/2026 RIP: 0010:io_serial_in+0x77/0xc0 drivers/tty/serial/8250/8250_port.c:400 Code: e8 1e 95 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 5f ac fa fc 41 03 1e 89 da ec <0f> b6 c0 5b 41 5c 41 5e 41 5f c3 cc cc cc cc cc 44 89 f9 80 e1 07 RSP: 0018:ffffc900001679d0 EFLAGS: 00000202 RAX: 1ffffffff332a600 RBX: 00000000000003fd RCX: 0000000000000000 RDX: 00000000000003fd RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffffff999537d0 R08: 0000000000000000 R09: 0000000000000000 R10: dffffc0000000000 R11: ffffffff852fe1b0 R12: dffffc0000000000 R13: 0000000000000000 R14: ffffffff99953540 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff88812633c000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fe9a7907420 CR3: 0000000055906000 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:1961 fifo_wait_for_lsr drivers/tty/serial/8250/8250_port.c:3234 [inline] serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3257 [inline] serial8250_console_write+0x120d/0x1b90 drivers/tty/serial/8250/8250_port.c:3342 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