INFO: task syz.0.17:6073 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.17 state:D stack:28984 pid:6073 tgid:6068 ppid:5928 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5295 [inline] __schedule+0x14de/0x5210 kernel/sched/core.c:6907 __schedule_loop kernel/sched/core.c:6989 [inline] rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7285 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_nested include/linux/fs.h:1073 [inline] lock_rename fs/namei.c:3756 [inline] __start_renaming+0x148/0x410 fs/namei.c:3852 filename_renameat2+0x38c/0x9c0 fs/namei.c:6119 __do_sys_rename fs/namei.c:6188 [inline] __se_sys_rename+0x55/0x2c0 fs/namei.c:6184 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: 0033:0x7f199cd5c629 RSP: 002b:00007f199c39d028 EFLAGS: 00000246 ORIG_RAX: 0000000000000052 RAX: ffffffffffffffda RBX: 00007f199cfd6090 RCX: 00007f199cd5c629 RDX: 0000000000000000 RSI: 0000200000000400 RDI: 0000200000006200 RBP: 00007f199cdf2b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f199cfd6128 R14: 00007f199cfd6090 R15: 00007ffe3a6f4bb8 Showing all locks held in the system: 1 lock held by khungtaskd/38: #0: ffffffff8dbcd480 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8dbcd480 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8dbcd480 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 4 locks held by kworker/u8:2/43: 2 locks held by getty/5557: #0: ffff888037e070a0 (&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 7 locks held by syz.0.17/6069: 2 locks held by syz.0.17/6073: #0: ffff888036938480 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493 #1: ffff888045321098 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1073 [inline] #1: ffff888045321098 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: lock_rename fs/namei.c:3756 [inline] #1: ffff888045321098 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: __start_renaming+0x148/0x410 fs/namei.c:3852 7 locks held by syz.1.18/6098: 2 locks held by syz.1.18/6102: #0: ffff8880409e2480 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493 #1: ffff888056b104b0 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1073 [inline] #1: ffff888056b104b0 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: lock_rename fs/namei.c:3756 [inline] #1: ffff888056b104b0 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: __start_renaming+0x148/0x410 fs/namei.c:3852 6 locks held by syz.2.19/6131: 2 locks held by syz.2.19/6135: #0: ffff88803fa10480 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493 #1: ffff888045309098 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1073 [inline] #1: ffff888045309098 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: lock_rename fs/namei.c:3756 [inline] #1: ffff888045309098 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: __start_renaming+0x148/0x410 fs/namei.c:3852 2 locks held by syz.3.20/6159: #0: ffff8880381ce480 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493 #1: ffff888045312868 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1073 [inline] #1: ffff888045312868 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: lock_rename fs/namei.c:3756 [inline] #1: ffff888045312868 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: __start_renaming+0x148/0x410 fs/namei.c:3852 7 locks held by syz.3.20/6164: 6 locks held by syz.4.21/6193: 2 locks held by syz.4.21/6197: #0: ffff888036ea2480 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493 #1: ffff88804504b450 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1073 [inline] #1: ffff88804504b450 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: lock_rename fs/namei.c:3756 [inline] #1: ffff88804504b450 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: __start_renaming+0x148/0x410 fs/namei.c:3852 2 locks held by syz.5.22/6233: #0: ffff88802a3dc480 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493 #1: ffff888045049098 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1073 [inline] #1: ffff888045049098 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: lock_rename fs/namei.c:3756 [inline] #1: ffff888045049098 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: __start_renaming+0x148/0x410 fs/namei.c:3852 6 locks held by syz.5.22/6238: 5 locks held by syz.6.23/6267: 2 locks held by syz.6.23/6271: #0: ffff8880291b4480 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493 #1: ffff88804525b450 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1073 [inline] #1: ffff88804525b450 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: lock_rename fs/namei.c:3756 [inline] #1: ffff88804525b450 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: __start_renaming+0x148/0x410 fs/namei.c:3852 2 locks held by syz.7.24/6302: #0: ffff888060a2e480 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493 #1: ffff88804504e3f0 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1073 [inline] #1: ffff88804504e3f0 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: lock_rename fs/namei.c:3756 [inline] #1: ffff88804504e3f0 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: __start_renaming+0x148/0x410 fs/namei.c:3852 7 locks held by syz.7.24/6306: ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 38 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+0xf90/0xfe0 kernel/hung_task.c:515 kthread+0x388/0x470 kernel/kthread.c:467 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: 43 Comm: kworker/u8:2 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Workqueue: bat_events batadv_tt_purge RIP: 0010:mark_lock+0x1/0x190 kernel/locking/lockdep.c:4714 Code: 0f b9 3a 90 41 89 e9 48 89 df 48 8b 2c 24 e9 b6 fd ff ff 66 0f 1f 44 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 55 <41> 57 41 56 41 55 41 54 53 8b 46 20 89 c1 81 e1 00 00 03 00 83 f9 RSP: 0018:ffffc90000b579f8 EFLAGS: 00000006 RAX: 0000000000000000 RBX: ffff88801faa9e00 RCX: ffffffff92d9b110 RDX: 0000000000000006 RSI: ffff88801faaa990 RDI: ffff88801faa9e00 RBP: 1ffff11003f5552a R08: ffffffff8f492877 R09: 1ffffffff1e9250e R10: dffffc0000000000 R11: fffffbfff1e9250f R12: ffff88801faaa9b8 R13: dffffc0000000000 R14: ffff88801faaa990 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff888126595000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005651fc9ba820 CR3: 0000000035f4a000 CR4: 00000000003526f0 Call Trace: mark_held_locks kernel/locking/lockdep.c:4325 [inline] __trace_hardirqs_on_caller kernel/locking/lockdep.c:4351 [inline] lockdep_hardirqs_on_prepare+0x178/0x260 kernel/locking/lockdep.c:4410 trace_hardirqs_on+0x28/0x40 kernel/trace/trace_preemptirq.c:78 __local_bh_enable_ip+0x1ae/0x2b0 kernel/softirq.c:306 local_bh_enable include/linux/bottom_half.h:33 [inline] spin_unlock_bh include/linux/spinlock_rt.h:116 [inline] batadv_tt_global_purge net/batman-adv/translation-table.c:2250 [inline] batadv_tt_purge+0x475/0xa10 net/batman-adv/translation-table.c:3510 process_one_work kernel/workqueue.c:3275 [inline] process_scheduled_works+0xaec/0x17a0 kernel/workqueue.c:3358 worker_thread+0xa50/0xfc0 kernel/workqueue.c:3439 kthread+0x388/0x470 kernel/kthread.c:467 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245