INFO: task syz.2.3866:20296 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.3866 state:D stack:27496 pid:20296 tgid:20272 ppid:17207 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] schedule+0x165/0x360 kernel/sched/core.c:7026 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7083 __mutex_lock_common kernel/locking/mutex.c:676 [inline] __mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:760 blk_trace_remove+0x20/0x40 kernel/trace/blktrace.c:406 sg_ioctl_common drivers/scsi/sg.c:1122 [inline] sg_ioctl+0x47b/0x2230 drivers/scsi/sg.c:1156 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f0e8e38eec9 RSP: 002b:00007f0e8bd6e038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f0e8e5e6360 RCX: 00007f0e8e38eec9 RDX: 0000000020000000 RSI: 0000000000001276 RDI: 0000000000000009 RBP: 00007f0e8e411f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f0e8e5e63f8 R14: 00007f0e8e5e6360 R15: 00007f0e8e70fa28 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8dd3b160 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8dd3b160 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8dd3b160 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by getty/5598: #0: ffff888033d600a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900036bb2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 3 locks held by kworker/u8:8/17493: #0: ffff88801e37a148 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff88801e37a148 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffffc90003affbc0 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline] #1: ffffc90003affbc0 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 #2: ffffffff8dd40bf8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline] #2: ffffffff8dd40bf8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730 kernel/rcu/tree_exp.h:957 3 locks held by syz.2.3866/20295: 1 lock held by syz.2.3866/20296: #0: ffff888142f41cc8 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_remove+0x20/0x40 kernel/trace/blktrace.c:406 1 lock held by syz-executor/20451: #0: ffffffff8dd40bf8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline] #0: ffffffff8dd40bf8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730 kernel/rcu/tree_exp.h:957 1 lock held by syz.4.3969/20657: #0: ffff888142f41cc8 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_setup+0xfb/0x1f0 kernel/trace/blktrace.c:613 1 lock held by syz.4.3969/20658: #0: ffff888142f41cc8 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_remove+0x20/0x40 kernel/trace/blktrace.c:406 1 lock held by syz.6.4319/21910: ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:332 [inline] watchdog+0xf60/0xfa0 kernel/hung_task.c:495 kthread+0x70e/0x8a0 kernel/kthread.c:463 ret_from_fork+0x436/0x7d0 arch/x86/kernel/process.c:148 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: 193 Comm: kworker/u8:5 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Workqueue: bat_events batadv_tt_purge RIP: 0010:lockdep_softirqs_on+0x46/0x1c0 kernel/locking/lockdep.c:4528 Code: 8b 1c 25 08 60 49 92 83 3d a6 11 c0 0d 00 0f 84 1d 01 00 00 65 8b 05 d9 94 ad 10 85 c0 0f 85 0e 01 00 00 83 bb 2c 0b 00 00 00 <0f> 85 01 01 00 00 83 3d 8d 97 b8 17 00 75 19 48 c7 04 24 00 00 00 RSP: 0018:ffffc90002e97890 EFLAGS: 00000046 RAX: 0000000000000000 RBX: ffff8880207c9e40 RCX: b23def5fe8f3c500 RDX: 0000000000000000 RSI: ffffffff8b9eea40 RDI: ffffffff8b05a207 RBP: ffffc90002e97958 R08: ffffffff8f5bed37 R09: 1ffffffff1eb7da6 R10: dffffc0000000000 R11: fffffbfff1eb7da7 R12: ffffffff8b05a207 R13: dffffc0000000000 R14: dffffc0000000000 R15: 1ffff920005d2f18 FS: 0000000000000000(0000) GS:ffff88812638a000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000404030 CR3: 000000000db36000 CR4: 00000000003526f0 Call Trace: __local_bh_enable_ip+0xe9/0x1c0 kernel/softirq.c:438 spin_unlock_bh include/linux/spinlock.h:396 [inline] batadv_tt_local_purge+0x2a7/0x340 net/batman-adv/translation-table.c:1315 batadv_tt_purge+0x35/0x9e0 net/batman-adv/translation-table.c:3509 process_one_work kernel/workqueue.c:3263 [inline] process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3346 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427 kthread+0x70e/0x8a0 kernel/kthread.c:463 ret_from_fork+0x436/0x7d0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245