INFO: task syz.0.17:5969 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:25544 pid:5969 ppid:5919 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5380 [inline] __schedule+0x14d2/0x44d0 kernel/sched/core.c:6699 schedule+0xbd/0x170 kernel/sched/core.c:6773 schedule_timeout+0x9b/0x280 kernel/time/timer.c:2143 do_wait_for_common kernel/sched/completion.c:95 [inline] __wait_for_common+0x3cb/0x6d0 kernel/sched/completion.c:116 wait_for_common kernel/sched/completion.c:127 [inline] wait_for_completion_state+0x1c/0x40 kernel/sched/completion.c:264 coredump_wait fs/coredump.c:443 [inline] do_coredump+0x85c/0x2480 fs/coredump.c:640 get_signal+0x1133/0x1400 kernel/signal.c:2888 arch_do_signal_or_restart+0x96/0x780 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174 exit_to_user_mode_prepare+0xf6/0x180 kernel/entry/common.c:210 irqentry_exit_to_user_mode+0x9/0x40 kernel/entry/common.c:315 exc_page_fault+0x8f/0x110 arch/x86/mm/fault.c:1524 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:608 RIP: 0033:0x7f48f984f927 RSP: 002b:00007ffc298773a0 EFLAGS: 00010206 RAX: 0000000000000000 RBX: 000000000000000b RCX: 0000000000027100 RDX: 00007ffc298773c0 RSI: 00007ffc298774f0 RDI: 000000000000000b RBP: 00007f48f9bd7da0 R08: 00000000000000a0 R09: 0000000000745d1e R10: 0000005450331b38 R11: 000000000000655a R12: 0000000000027671 R13: 00007f48f9bd6090 R14: ffffffffffffffff R15: 00007ffc29975610 INFO: task syz.0.17:5971 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:26856 pid:5971 ppid:5919 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5380 [inline] __schedule+0x14d2/0x44d0 kernel/sched/core.c:6699 schedule+0xbd/0x170 kernel/sched/core.c:6773 coredump_task_exit kernel/exit.c:436 [inline] do_exit+0x4a0/0x23c0 kernel/exit.c:825 do_group_exit+0x21b/0x2d0 kernel/exit.c:1024 get_signal+0x12fc/0x1400 kernel/signal.c:2902 arch_do_signal_or_restart+0x96/0x780 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174 exit_to_user_mode_prepare+0xf6/0x180 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302 do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:87 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f48f998eba9 RSP: 002b:00007f48fa7d90e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007f48f9bd6098 RCX: 00007f48f998eba9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f48f9bd6098 RBP: 00007f48f9bd6090 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f48f9bd6128 R14: 00007ffc299752b0 R15: 00007ffc29975398 Showing all locks held in the system: 1 lock held by khungtaskd/29: #0: ffffffff8cd2fe20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline] #0: ffffffff8cd2fe20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline] #0: ffffffff8cd2fe20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633 3 locks held by kworker/u4:2/42: 6 locks held by kworker/u4:11/3514: 2 locks held by getty/5553: #0: ffff88802caba0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000326e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x425/0x1380 drivers/tty/n_tty.c:2217 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 29 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Call Trace: dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106 nmi_cpu_backtrace+0x39b/0x3d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x2f0 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline] watchdog+0xf41/0xf80 kernel/hung_task.c:379 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 42 Comm: kworker/u4:2 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Workqueue: bat_events batadv_nc_worker RIP: 0010:debug_lockdep_rcu_enabled+0x20/0x30 kernel/rcu/update.c:320 Code: cc cc cc cc cc cc cc cc cc cc f3 0f 1e fa 31 c0 83 3d 7f 76 dc 03 00 74 1d 83 3d f6 a9 dc 03 00 74 14 65 48 8b 0d 50 9a 95 75 <31> c0 83 b9 dc 0a 00 00 00 0f 94 c0 c3 cc cc cc 66 0f 1f 00 48 8b RSP: 0018:ffffc90000b2fb58 EFLAGS: 00000202 RAX: 0000000000000000 RBX: ffff888061ef5e00 RCX: ffff888018af0000 RDX: 0000000000000000 RSI: ffffffff8aaace20 RDI: ffffffff8afc72c0 RBP: ffff88805a61caa8 R08: dffffc0000000000 R09: 1ffffffff21b4ea0 R10: dffffc0000000000 R11: fffffbfff21b4ea1 R12: dffffc0000000000 R13: ffffffff8a367332 R14: ffff88805d6c0c80 R15: 0000000000000155 FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000556fd0e30a38 CR3: 000000000cb30000 CR4: 00000000003506e0 Call Trace: rcu_read_lock include/linux/rcupdate.h:787 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline] batadv_nc_worker+0xf8/0x610 net/batman-adv/network-coding.c:719 process_one_work kernel/workqueue.c:2634 [inline] process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293