INFO: task syz.7.7734:31308 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.7.7734 state:D stack:24832 pid:31308 ppid:21687 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5244 [inline] __schedule+0x10ec/0x40b0 kernel/sched/core.c:6561 schedule+0xb9/0x180 kernel/sched/core.c:6637 rwsem_down_write_slowpath+0xbed/0x1090 kernel/locking/rwsem.c:1189 mmap_write_lock include/linux/mmap_lock.h:71 [inline] exit_mmap+0x20f/0x8e0 mm/mmap.c:3258 __mmput+0x118/0x3c0 kernel/fork.c:1200 exit_mm+0x1e6/0x2c0 kernel/exit.c:565 do_exit+0x8c1/0x2400 kernel/exit.c:867 do_group_exit+0x217/0x2d0 kernel/exit.c:1022 get_signal+0x1272/0x1350 kernel/signal.c:2871 arch_do_signal_or_restart+0xb0/0x1230 arch/x86/kernel/signal.c:871 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:87 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f213658ebe9 RSP: 002b:00007f21373730e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007f21367c6098 RCX: 00007f213658ebe9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f21367c6098 RBP: 00007f21367c6090 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f21367c6128 R14: 00007ffd8a2c0890 R15: 00007ffd8a2c0978 Showing all locks held in the system: 1 lock held by rcu_tasks_kthre/12: #0: ffffffff8cb2b370 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517 1 lock held by rcu_tasks_trace/13: #0: ffffffff8cb2bb90 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517 1 lock held by khungtaskd/28: #0: ffffffff8cb2a9e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #0: ffffffff8cb2a9e0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #0: ffffffff8cb2a9e0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6513 4 locks held by klogd/3626: #0: ffff8880b8e3aa98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:537 #1: ffff8880267a8658 (&ei->socket.wq.wait){..-.}-{2:2}, at: psi_task_switch+0x398/0x6d0 kernel/sched/psi.c:999 #2: ffff88807d49e358 (&p->pi_lock){-.-.}-{2:2}, at: try_to_wake_up+0x5c/0x1080 kernel/sched/core.c:4111 #3: ffff8880b8e3aa98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:537 2 locks held by getty/4028: #0: ffff88814d27f098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244 #1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x41b/0x1380 drivers/tty/n_tty.c:2198 2 locks held by kworker/1:7/4374: #0: ffff888017472138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc90004167d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 3 locks held by kworker/u4:17/5147: #0: ffff888017479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc900033d7d00 ((work_completion)(&map->work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #2: ffffffff8cb306b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:323 [inline] #2: ffffffff8cb306b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x346/0x830 kernel/rcu/tree_exp.h:962 4 locks held by kworker/u4:37/17915: #0: ffff888017616938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc90004e6fd00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #2: ffffffff8dd35210 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x132/0xb80 net/core/net_namespace.c:594 #3: ffffffff8cb30580 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0x48/0x600 kernel/rcu/tree.c:4023 1 lock held by syz.7.7734/31308: #0: ffff88802f4208d8 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:71 [inline] #0: ffff88802f4208d8 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x20f/0x8e0 mm/mmap.c:3258 2 locks held by kworker/u4:0/703: #0: ffff888017479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc90004c6fd00 ((work_completion)(&map->work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 2 locks held by syz.2.8426/1303: #0: ffffffff96c39128 (&pmus_srcu){....}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #0: ffffffff96c39128 (&pmus_srcu){....}-{0:0}, at: srcu_read_lock include/linux/srcu.h:165 [inline] #0: ffffffff96c39128 (&pmus_srcu){....}-{0:0}, at: perf_init_event kernel/events/core.c:11624 [inline] #0: ffffffff96c39128 (&pmus_srcu){....}-{0:0}, at: perf_event_alloc+0xbe2/0x21b0 kernel/events/core.c:11950 #1: ffffffff8cb7f968 (event_mutex){+.+.}-{3:3}, at: perf_trace_init+0x4c/0x2d0 kernel/trace/trace_event_perf.c:221 2 locks held by syz.2.8426/1313: #0: ffffffff96c39128 (&pmus_srcu){....}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #0: ffffffff96c39128 (&pmus_srcu){....}-{0:0}, at: srcu_read_lock include/linux/srcu.h:165 [inline] #0: ffffffff96c39128 (&pmus_srcu){....}-{0:0}, at: perf_init_event kernel/events/core.c:11624 [inline] #0: ffffffff96c39128 (&pmus_srcu){....}-{0:0}, at: perf_event_alloc+0xbe2/0x21b0 kernel/events/core.c:11950 #1: ffffffff8cb7f968 (event_mutex){+.+.}-{3:3}, at: perf_trace_init+0x4c/0x2d0 kernel/trace/trace_event_perf.c:221 4 locks held by syz.9.8428/1312: #0: ffffffff96c39128 (&pmus_srcu){....}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #0: ffffffff96c39128 (&pmus_srcu){....}-{0:0}, at: srcu_read_lock include/linux/srcu.h:165 [inline] #0: ffffffff96c39128 (&pmus_srcu){....}-{0:0}, at: perf_init_event kernel/events/core.c:11624 [inline] #0: ffffffff96c39128 (&pmus_srcu){....}-{0:0}, at: perf_event_alloc+0xbe2/0x21b0 kernel/events/core.c:11950 #1: ffffffff8cb7f968 (event_mutex){+.+.}-{3:3}, at: perf_trace_init+0x4c/0x2d0 kernel/trace/trace_event_perf.c:221 #2: ffffffff8cb71b08 (tracepoints_mutex){+.+.}-{3:3}, at: tracepoint_probe_register_prio kernel/tracepoint.c:507 [inline] #2: ffffffff8cb71b08 (tracepoints_mutex){+.+.}-{3:3}, at: tracepoint_probe_register+0x3c/0x90 kernel/tracepoint.c:531 #3: ffffffff8cb306b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:323 [inline] #3: ffffffff8cb306b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x346/0x830 kernel/rcu/tree_exp.h:962 2 locks held by syz.6.8430/1320: #0: ffffffff96c39128 (&pmus_srcu){....}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #0: ffffffff96c39128 (&pmus_srcu){....}-{0:0}, at: srcu_read_lock include/linux/srcu.h:165 [inline] #0: ffffffff96c39128 (&pmus_srcu){....}-{0:0}, at: perf_init_event kernel/events/core.c:11624 [inline] #0: ffffffff96c39128 (&pmus_srcu){....}-{0:0}, at: perf_event_alloc+0xbe2/0x21b0 kernel/events/core.c:11950 #1: ffffffff8cb7f968 (event_mutex){+.+.}-{3:3}, at: perf_trace_init+0x4c/0x2d0 kernel/trace/trace_event_perf.c:221 2 locks held by syz.8.8429/1317: #0: ffffffff96c39128 (&pmus_srcu){....}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #0: ffffffff96c39128 (&pmus_srcu){....}-{0:0}, at: srcu_read_lock include/linux/srcu.h:165 [inline] #0: ffffffff96c39128 (&pmus_srcu){....}-{0:0}, at: perf_init_event kernel/events/core.c:11624 [inline] #0: ffffffff96c39128 (&pmus_srcu){....}-{0:0}, at: perf_event_alloc+0xbe2/0x21b0 kernel/events/core.c:11950 #1: ffffffff8cb7f968 (event_mutex){+.+.}-{3:3}, at: perf_trace_init+0x4c/0x2d0 kernel/trace/trace_event_perf.c:221 3 locks held by syz.8.8429/1329: ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 28 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Call Trace: dump_stack_lvl+0x168/0x22e lib/dump_stack.c:106 nmi_cpu_backtrace+0x3f4/0x470 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x1d4/0x450 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline] watchdog+0xeee/0xf30 kernel/hung_task.c:377 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 5147 Comm: kworker/u4:17 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Workqueue: bat_events batadv_tt_purge RIP: 0010:__sanitizer_cov_trace_pc+0x58/0x60 kernel/kcov.c:234 Code: f8 15 00 00 83 fa 02 75 21 48 8b 91 00 16 00 00 48 8b 32 48 8d 7e 01 8b 89 fc 15 00 00 48 39 cf 73 08 48 89 3a 48 89 44 f2 08 0f 1f 80 00 00 00 00 48 8b 04 24 65 48 8b 15 b4 9e 81 7e 65 8b RSP: 0018:ffffc900033d77f8 EFLAGS: 00000093 RAX: ffffffff818a68a6 RBX: 0000000000000001 RCX: ffff88807dad9dc0 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc900033d78f8 R08: dffffc0000000000 R09: fffffbfff215c249 R10: fffffbfff215c249 R11: 1ffffffff215c248 R12: ffffffff8cb7cea0 R13: 1ffff9200067af0c R14: ffff88805b22c480 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f0458db4990 CR3: 000000007df64000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000200000000300 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: trace_call_bpf+0x1b6/0x680 kernel/trace/bpf_trace.c:135 perf_trace_run_bpf_submit+0x79/0x1c0 kernel/events/core.c:9997 perf_trace_preemptirq_template+0x287/0x330 include/trace/events/preemptirq.h:14 trace_irq_disable_rcuidle+0xd3/0x140 include/trace/events/preemptirq.h:36 __local_bh_enable_ip+0xcb/0x1b0 kernel/softirq.c:403 spin_unlock_bh include/linux/spinlock.h:396 [inline] batadv_tt_local_purge+0x2a7/0x340 net/batman-adv/translation-table.c:1371 batadv_tt_purge+0x31/0x9f0 net/batman-adv/translation-table.c:3582 process_one_work+0x898/0x1160 kernel/workqueue.c:2292 worker_thread+0xaa2/0x1250 kernel/workqueue.c:2439 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295