INFO: task syz.2.674:8814 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.674 state:D stack:25928 pid:8814 tgid:8812 ppid:5885 task_flags:0x400140 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0x165/0x360 kernel/sched/core.c:7058 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7115 __mutex_lock_common kernel/locking/mutex.c:676 [inline] __mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:760 relay_open+0x3b8/0x920 kernel/relay.c:516 do_blk_trace_setup+0x561/0x980 kernel/trace/blktrace.c:572 blk_trace_setup+0x116/0x1f0 kernel/trace/blktrace.c:614 blk_trace_ioctl+0x181/0x430 kernel/trace/blktrace.c:712 blkdev_ioctl+0x416/0x6d0 block/ioctl.c:694 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:598 [inline] __se_sys_ioctl+0xf9/0x170 fs/ioctl.c:584 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: 0033:0x7f081418ebe9 RSP: 002b:00007f08150ce038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f08143b5fa0 RCX: 00007f081418ebe9 RDX: 0000200000000140 RSI: 00000000c0481273 RDI: 000000000000000b RBP: 00007f0814211e19 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f08143b6038 R14: 00007f08143b5fa0 R15: 00007f08144dfa28 INFO: task syz.3.682:8853 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.682 state:D stack:25128 pid:8853 tgid:8845 ppid:5884 task_flags:0x400140 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0x165/0x360 kernel/sched/core.c:7058 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7115 __mutex_lock_common kernel/locking/mutex.c:676 [inline] __mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:760 relay_open+0x3b8/0x920 kernel/relay.c:516 do_blk_trace_setup+0x561/0x980 kernel/trace/blktrace.c:572 blk_trace_setup+0x116/0x1f0 kernel/trace/blktrace.c:614 sg_ioctl_common drivers/scsi/sg.c:1114 [inline] sg_ioctl+0xaf3/0x2230 drivers/scsi/sg.c:1156 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:598 [inline] __se_sys_ioctl+0xf9/0x170 fs/ioctl.c:584 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: 0033:0x7f469498ebe9 RSP: 002b:00007f4695844038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f4694bb6270 RCX: 00007f469498ebe9 RDX: 0000200000000b40 RSI: 00000000c0481273 RDI: 0000000000000009 RBP: 00007f4694a11e19 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f4694bb6308 R14: 00007f4694bb6270 R15: 00007f4694cdfa28 INFO: task syz.3.682:8855 blocked for more than 145 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.682 state:D stack:26760 pid:8855 tgid:8845 ppid:5884 task_flags:0x400140 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0x165/0x360 kernel/sched/core.c:7058 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7115 __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:598 [inline] __se_sys_ioctl+0xf9/0x170 fs/ioctl.c:584 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: 0033:0x7f469498ebe9 RSP: 002b:00007f4695823038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f4694bb6360 RCX: 00007f469498ebe9 RDX: 0000000020000000 RSI: 0000000000001276 RDI: 0000000000000009 RBP: 00007f4694a11e19 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f4694bb63f8 R14: 00007f4694bb6360 R15: 00007f4694cdfa28 Showing all locks held in the system: 5 locks held by kworker/u8:1/13: 1 lock held by khungtaskd/31: #0: ffffffff8e139ee0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e139ee0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e139ee0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by kworker/u8:4/59: #0: ffff888146a86948 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff888146a86948 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319 #1: ffffc9000210fbc0 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc9000210fbc0 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319 2 locks held by getty/5622: #0: ffff88814dd860a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900036bc2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 2 locks held by syz.4.616/8526: 2 locks held by syz.2.674/8814: #0: ffff888142bfc408 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_setup+0xfb/0x1f0 kernel/trace/blktrace.c:613 #1: ffffffff8e18d6c8 (relay_channels_mutex){+.+.}-{4:4}, at: relay_open+0x3b8/0x920 kernel/relay.c:516 2 locks held by syz.3.682/8853: #0: ffff888025156178 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_setup+0xfb/0x1f0 kernel/trace/blktrace.c:613 #1: ffffffff8e18d6c8 (relay_channels_mutex){+.+.}-{4:4}, at: relay_open+0x3b8/0x920 kernel/relay.c:516 1 lock held by syz.3.682/8855: #0: ffff888025156178 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_remove+0x20/0x40 kernel/trace/blktrace.c:406 1 lock held by syz-executor/8965: #0: ffffffff8e13f978 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline] #0: ffffffff8e13f978 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730 kernel/rcu/tree_exp.h:957 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 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:328 [inline] watchdog+0xf93/0xfe0 kernel/hung_task.c:491 kthread+0x70e/0x8a0 kernel/kthread.c:463 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148 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: 59 Comm: kworker/u8:4 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Workqueue: bat_events batadv_nc_worker RIP: 0010:__lock_acquire+0x870/0xd20 kernel/locking/lockdep.c:5232 Code: f0 41 89 cf 41 c1 c7 13 29 ce 41 31 f7 01 c1 44 29 f8 44 01 f9 41 c1 c7 04 41 31 c7 49 c1 e7 20 49 09 cf 83 3d 84 56 06 0e 00 <0f> 85 36 02 00 00 48 83 7c 24 28 00 0f 84 bc 01 00 00 41 8b 46 f8 RSP: 0018:ffffc9000210f880 EFLAGS: 00000046 RAX: 00000000f89a32d7 RBX: 0000000000000002 RCX: 00000000da3390f3 RDX: 000000003b747380 RSI: 000000003e521b42 RDI: ffff888021ef3c00 RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff8b47a72a R10: dffffc0000000000 R11: fffffbfff1f47187 R12: 00000000fe8c41a7 R13: ffff888021ef46f0 R14: ffff888021ef4740 R15: 29a83f7ada3390f3 FS: 0000000000000000(0000) GS:ffff888125d1b000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f2e23cdeccc CR3: 0000000077800000 CR4: 00000000003526f0 Call Trace: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:841 [inline] batadv_nc_process_nc_paths+0xdb/0x3a0 net/batman-adv/network-coding.c:687 batadv_nc_worker+0x429/0x610 net/batman-adv/network-coding.c:728 process_one_work kernel/workqueue.c:3236 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3319 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400 kthread+0x70e/0x8a0 kernel/kthread.c:463 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245