INFO: task syz.4.520:9599 blocked for more than 143 seconds. Not tainted 6.16.0-rc7-syzkaller-00140-gec2df4364666 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.520 state:D stack:25128 pid:9599 tgid:9598 ppid:6778 task_flags:0x400140 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5397 [inline] __schedule+0x16aa/0x4c90 kernel/sched/core.c:6786 __schedule_loop kernel/sched/core.c:6864 [inline] schedule+0x165/0x360 kernel/sched/core.c:6879 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6936 rwsem_down_read_slowpath+0x552/0x880 kernel/locking/rwsem.c:1084 __down_read_common kernel/locking/rwsem.c:1248 [inline] __down_read kernel/locking/rwsem.c:1261 [inline] down_read+0x98/0x2e0 kernel/locking/rwsem.c:1526 __super_lock fs/super.c:59 [inline] super_lock+0x2a9/0x3b0 fs/super.c:121 __iterate_supers+0x126/0x250 fs/super.c:923 ksys_sync+0x94/0x150 fs/sync.c:102 __ia32_sys_sync+0xe/0x20 fs/sync.c:113 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: 0033:0x7f267e58e9a9 RSP: 002b:00007f267f3db038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 00007f267e7b5fa0 RCX: 00007f267e58e9a9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007f267e7b5fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f267e7b5fa0 R15: 00007ffe6eb227d8 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e13f0e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e13f0e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e13f0e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6770 1 lock held by udevd/5207: #0: ffff8880b8639e18 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:606 2 locks held by getty/5599: #0: ffff8880311a10a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000363c2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 2 locks held by syz-executor/5835: 2 locks held by syz-executor/6588: #0: ffffffff8e87d008 (bio_slab_lock){+.+.}-{4:4}, at: bio_put_slab block/bio.c:140 [inline] #0: ffffffff8e87d008 (bio_slab_lock){+.+.}-{4:4}, at: bioset_exit+0x44a/0x690 block/bio.c:1758 #1: ffffffff8e144ac0 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x570 kernel/rcu/tree.c:3786 2 locks held by udevd/6976: 1 lock held by syz.4.520/9599: #0: ffff8880317560e0 (&type->s_umount_key#63){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline] #0: ffff8880317560e0 (&type->s_umount_key#63){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121 5 locks held by syz.7.936/11864: 3 locks held by syz.8.937/11870: #0: ffff888039800920 (&c->sb_lock){+.+.}-{4:4}, at: bch2_fs_alloc fs/bcachefs/super.c:917 [inline] #0: ffff888039800920 (&c->sb_lock){+.+.}-{4:4}, at: bch2_fs_open+0x11e5/0x2600 fs/bcachefs/super.c:2433 #1: ffff8880398049d8 (&c->mark_lock){++++}-{0:0}, at: bch2_sb_replicas_to_cpu_replicas+0x117/0x1a0 fs/bcachefs/replicas.c:600 #2: ffffffff8e144bf8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:304 [inline] #2: ffffffff8e144bf8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730 kernel/rcu/tree_exp.h:998 2 locks held by dhcpcd-run-hook/11885: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-rc7-syzkaller-00140-gec2df4364666 #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:158 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:307 [inline] watchdog+0xfee/0x1030 kernel/hung_task.c:470 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3fc/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: 36 Comm: kworker/u8:2 Not tainted 6.16.0-rc7-syzkaller-00140-gec2df4364666 #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:arch_atomic_read arch/x86/include/asm/atomic.h:23 [inline] RIP: 0010:raw_atomic_read include/linux/atomic/atomic-arch-fallback.h:457 [inline] RIP: 0010:rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline] RIP: 0010:rcu_is_watching+0x5a/0xb0 kernel/rcu/tree.c:745 Code: f0 48 c1 e8 03 42 80 3c 38 00 74 08 4c 89 f7 e8 2c e2 78 00 48 c7 c3 58 bf 9d 92 49 03 1e 48 89 d8 48 c1 e8 03 42 0f b6 04 38 <84> c0 75 34 8b 03 65 ff 0d 39 65 f5 10 74 11 83 e0 04 c1 e8 02 5b RSP: 0018:ffffc90000ac7a00 EFLAGS: 00000a06 RAX: 0000000000000000 RBX: ffff8880b8732f58 RCX: f627edbd24b16a00 RDX: ffff88801dabda00 RSI: ffffffff8be1ba60 RDI: ffffffff8be1ba20 RBP: ffff88803550cee0 R08: 0000000000000000 R09: ffffffff8b345592 R10: dffffc0000000000 R11: ffffffff8b3454c0 R12: dffffc0000000000 R13: ffffffff8b345592 R14: ffffffff8dba8c78 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff888125d57000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffe1e820b48 CR3: 0000000031b7a000 CR4: 00000000003526f0 Call Trace: rcu_read_lock include/linux/rcupdate.h:842 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline] batadv_nc_worker+0x10c/0x610 net/batman-adv/network-coding.c:719 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3321 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245