INFO: task syz.1.159:7217 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_time[ 358.006702][ T38] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.159 state:D stack:28952 pid:7217 tgid:7201 ppid:5801 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5260 [inline] __schedule+0x147b/0x4f50 kernel/sched/core.c:6867 __schedule_loop kernel/sched/core.c:6949 [inline] rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7245 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline] __rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline] __rt_mutex_slowlock_locked+0x1fc5/0x2600 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_nested include/linux/fs.h:1072 [inline] __start_dirop fs/namei.c:2873 [inline] start_dirop fs/namei.c:2884 [inline] filename_create+0x200/0x370 fs/namei.c:4888 do_mknodat+0x189/0x630 fs/namei.c:5035 __do_sys_mknod fs/namei.c:5085 [inline] __se_sys_mknod fs/namei.c:5083 [inline] __x64_sys_mknod+0x8c/0xa0 fs/namei.c:5083 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f19f5e6acb9 RSP: 002b:00007f19f40a5028 EFLAGS: 00000246 ORIG_RAX: 0000000000000085 RAX: ffffffffffffffda RBX: 00007f19f60e6090 RCX: 00007f19f5e6acb9 RDX: 0000000000000703 RSI: 0000000000001000 RDI: 0000200000000080 RBP: 00007f19f5ed8bf7 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f19f60e6128 R14: 00007f19f60e6090 R15: 00007ffc0f0dff28 INFO: task syz.1.159:7218 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.159 state:D stack:27232 pid:7218 tgid:7201 ppid:5801 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5260 [inline] __schedule+0x147b/0x4f50 kernel/sched/core.c:6867 __schedule_loop kernel/sched/core.c:6949 [inline] rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7245 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline] __rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline] __rt_mutex_slowlock_locked+0x1fc5/0x2600 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:1027 [inline] open_last_lookups fs/namei.c:4546 [inline] path_openat+0xb65/0x3e70 fs/namei.c:4793 do_filp_open+0x22d/0x490 fs/namei.c:4823 do_sys_openat2+0x12f/0x220 fs/open.c:1430 do_sys_open fs/open.c:1436 [inline] __do_sys_openat fs/open.c:1452 [inline] __se_sys_openat fs/open.c:1447 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1447 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f19f5e6acb9 RSP: 002b:00007f19f4084028 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f19f60e6180 RCX: 00007f19f5e6acb9 RDX: 0000000000183042 RSI: 0000200000000740 RDI: ffffffffffffff9c RBP: 00007f19f5ed8bf7 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000015 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f19f60e6218 R14: 00007f19f60e6180 R15: 00007ffc0f0dff28 INFO: task syz.1.159:7219 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.159 state:D stack:28672 pid:7219 tgid:7201 ppid:5801 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5260 [inline] __schedule+0x147b/0x4f50 kernel/sched/core.c:6867 __schedule_loop kernel/sched/core.c:6949 [inline] rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7245 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline] __rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline] __rt_mutex_slowlock_locked+0x1fc5/0x2600 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:1027 [inline] open_last_lookups fs/namei.c:4546 [inline] path_openat+0xb65/0x3e70 fs/namei.c:4793 do_filp_open+0x22d/0x490 fs/namei.c:4823 do_sys_openat2+0x12f/0x220 fs/open.c:1430 do_sys_open fs/open.c:1436 [inline] __do_sys_openat fs/open.c:1452 [inline] __se_sys_openat fs/open.c:1447 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1447 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f19f5e6acb9 RSP: 002b:00007f19f3c61028 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f19f60e6270 RCX: 00007f19f5e6acb9 RDX: 0000000000000042 RSI: 0000200000000040 RDI: ffffffffffffff9c RBP: 00007f19f5ed8bf7 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f19f60e6308 R14: 00007f19f60e6270 R15: 00007ffc0f0dff28 INFO: task syz.1.159:7220 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.159 state:D stack:28616 pid:7220 tgid:7201 ppid:5801 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5260 [inline] __schedule+0x147b/0x4f50 kernel/sched/core.c:6867 __schedule_loop kernel/sched/core.c:6949 [inline] rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7245 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline] __rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline] __rt_mutex_slowlock_locked+0x1fc5/0x2600 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:1027 [inline] open_last_lookups fs/namei.c:4546 [inline] path_openat+0xb65/0x3e70 fs/namei.c:4793 do_filp_open+0x22d/0x490 fs/namei.c:4823 do_sys_openat2+0x12f/0x220 fs/open.c:1430 do_sys_open fs/open.c:1436 [inline] __do_sys_openat fs/open.c:1452 [inline] __se_sys_openat fs/open.c:1447 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1447 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f19f5e6acb9 RSP: 002b:00007f19f383e028 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f19f60e6360 RCX: 00007f19f5e6acb9 RDX: 000000000000275a RSI: 00002000000006c0 RDI: ffffffffffffff9c RBP: 00007f19f5ed8bf7 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f19f60e63f8 R14: 00007f19f60e6360 R15: 00007ffc0f0dff28 INFO: task syz.1.159:7221 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.159 state:D stack:28240 pid:7221 tgid:7201 ppid:5801 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5260 [inline] __schedule+0x147b/0x4f50 kernel/sched/core.c:6867 __schedule_loop kernel/sched/core.c:6949 [inline] rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7245 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline] __rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline] __rt_mutex_slowlock_locked+0x1fc5/0x2600 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:1027 [inline] open_last_lookups fs/namei.c:4546 [inline] path_openat+0xb65/0x3e70 fs/namei.c:4793 do_filp_open+0x22d/0x490 fs/namei.c:4823 do_sys_openat2+0x12f/0x220 fs/open.c:1430 do_sys_open fs/open.c:1436 [inline] __do_sys_openat fs/open.c:1452 [inline] __se_sys_openat fs/open.c:1447 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1447 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f19f5e6acb9 RSP: 002b:00007f19f341b028 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f19f60e6450 RCX: 00007f19f5e6acb9 RDX: 0000000000042042 RSI: 0000200000000080 RDI: ffffffffffffff9c RBP: 00007f19f5ed8bf7 R08: 0000000000000000 R09: 0000000000000000 R10: 000000000000014a R11: 0000000000000246 R12: 0000000000000000 R13: 00007f19f60e64e8 R14: 00007f19f60e6450 R15: 00007ffc0f0dff28 Showing all locks held in the system: 4 locks held by kworker/u8:1/13: #0: ffff88801a2d4938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline] #0: ffff88801a2d4938 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3340 #1: ffffc90000127bc0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline] #1: ffffc90000127bc0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3340 #2: ffffffff8ec9b4c0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xfe/0x7b0 net/core/net_namespace.c:670 #3: ffff88806298d7b8 (&wg->device_update_lock){+.+.}-{4:4}, at: wg_destruct+0x116/0x310 drivers/net/wireguard/device.c:249 4 locks held by pr/legacy/17: 1 lock held by khungtaskd/38: #0: ffffffff8d9aea00 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8d9aea00 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8d9aea00 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 4 locks held by kworker/u8:4/68: 4 locks held by kworker/u8:9/1465: #0: ffff888140465138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline] #0: ffff888140465138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3340 #1: ffffc90005bc7bc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline] #1: ffffc90005bc7bc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3340 #2: ffff888029cce0d0 (&type->s_umount_key#110){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:563 #3: ffff888051c6ed28 (&jfs_ip->commit_mutex){+.+.}-{4:4}, at: jfs_commit_inode+0x1ca/0x530 fs/jfs/inode.c:108 2 locks held by getty/5562: #0: ffff8880357100a0 (&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 kworker/u8:21/7060: 4 locks held by syz.1.159/7202: 2 locks held by syz.1.159/7217: #0: ffff888029cce480 (sb_writers#29){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:499 #1: ffff888051c6f0f8 (&type->i_mutex_dir_key#18/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1072 [inline] #1: ffff888051c6f0f8 (&type->i_mutex_dir_key#18/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2873 [inline] #1: ffff888051c6f0f8 (&type->i_mutex_dir_key#18/1){+.+.}-{4:4}, at: start_dirop fs/namei.c:2884 [inline] #1: ffff888051c6f0f8 (&type->i_mutex_dir_key#18/1){+.+.}-{4:4}, at: filename_create+0x200/0x370 fs/namei.c:4888 2 locks held by syz.1.159/7218: #0: ffff888029cce480 (sb_writers#29){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:499 #1: ffff888051c6f0f8 (&type->i_mutex_dir_key#19){++++}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline] #1: ffff888051c6f0f8 (&type->i_mutex_dir_key#19){++++}-{4:4}, at: open_last_lookups fs/namei.c:4546 [inline] #1: ffff888051c6f0f8 (&type->i_mutex_dir_key#19){++++}-{4:4}, at: path_openat+0xb65/0x3e70 fs/namei.c:4793 2 locks held by syz.1.159/7219: #0: ffff888029cce480 (sb_writers#29){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:499 #1: ffff888051c6f0f8 (&type->i_mutex_dir_key#19){++++}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline] #1: ffff888051c6f0f8 (&type->i_mutex_dir_key#19){++++}-{4:4}, at: open_last_lookups fs/namei.c:4546 [inline] #1: ffff888051c6f0f8 (&type->i_mutex_dir_key#19){++++}-{4:4}, at: path_openat+0xb65/0x3e70 fs/namei.c:4793 2 locks held by syz.1.159/7220: #0: ffff888029cce480 (sb_writers#29){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:499 #1: ffff888051c6f0f8 (&type->i_mutex_dir_key#19){++++}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline] #1: ffff888051c6f0f8 (&type->i_mutex_dir_key#19){++++}-{4:4}, at: open_last_lookups fs/namei.c:4546 [inline] #1: ffff888051c6f0f8 (&type->i_mutex_dir_key#19){++++}-{4:4}, at: path_openat+0xb65/0x3e70 fs/namei.c:4793 2 locks held by syz.1.159/7221: #0: ffff888029cce480 (sb_writers#29){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:499 #1: ffff888051c6f0f8 (&type->i_mutex_dir_key#19){++++}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline] #1: ffff888051c6f0f8 (&type->i_mutex_dir_key#19){++++}-{4:4}, at: open_last_lookups fs/namei.c:4546 [inline] #1: ffff888051c6f0f8 (&type->i_mutex_dir_key#19){++++}-{4:4}, at: path_openat+0xb65/0x3e70 fs/namei.c:4793 9 locks held by syz-executor/7406: 3 locks held by udevd/7553: 2 locks held by syz-executor/8538: 5 locks held by syz.9.348/8925: 3 locks held by syz.4.353/8952: #0: ffff88803a08c0d0 (&type->s_umount_key#58/1){+.+.}-{4:4}, at: alloc_super+0x28c/0xab0 fs/super.c:344 #1: ffff888027004cb8 (btrfs-tree-00){++++}-{4:4}, at: btrfs_tree_read_lock_nested+0x31/0x200 fs/btrfs/locking.c:145 #2: ffffffff8d613e38 (bit_wait_table + i){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:44 [inline] #2: ffffffff8d613e38 (bit_wait_table + i){+.+.}-{3:3}, at: finish_wait kernel/sched/wait.c:394 [inline] #2: ffffffff8d613e38 (bit_wait_table + i){+.+.}-{3:3}, at: __wait_on_bit+0x1fe/0x300 kernel/sched/wait_bit.c:55 1 lock held by syz.6.355/8959: 3 locks held by dhcpcd-run-hook/8981: ============================================= 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 01/13/2026 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+0xf90/0xfe0 kernel/hung_task.c:515 kthread+0x726/0x8b0 kernel/kthread.c:463 ret_from_fork+0x51b/0xa40 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 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 01/13/2026 RIP: 0010:io_serial_in+0x77/0xc0 drivers/tty/serial/8250/8250_port.c:400 Code: e8 3e bb ab 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 7f cd 0e fd 41 03 1e 89 da ec <0f> b6 c0 5b 41 5c 41 5e 41 5f e9 1a 0b db 05 cc 44 89 f9 80 e1 07 RSP: 0018:ffffc90000167950 EFLAGS: 00000202 RAX: 1ffffffff3276100 RBX: 00000000000003fd RCX: 0000000000000000 RDX: 00000000000003fd RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffffff993b1010 R08: 0000000000000000 R09: 0000000000000000 R10: dffffc0000000000 R11: ffffffff8515a100 R12: dffffc0000000000 R13: 0000000000000000 R14: ffffffff993b0d80 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8881269d9000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fd6c42b56b8 CR3: 000000002684a000 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:3109 [inline] console_flush_one_record+0x68b/0xb90 kernel/printk/printk.c:3215 legacy_kthread_func+0x1b6/0x250 kernel/printk/printk.c:3674 kthread+0x726/0x8b0 kernel/kthread.c:463 ret_from_fork+0x51b/0xa40 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246