INFO: task syz.1.213:6707 blocked for more than 143 seconds. Not tainted 6.16.0-rc2-syzkaller-00082-gfb4d33ab452e #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.213 state:D stack:28768 pid:6707 tgid:6698 ppid:5826 task_flags:0x400040 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5396 [inline] __schedule+0x116a/0x5de0 kernel/sched/core.c:6785 __schedule_loop kernel/sched/core.c:6863 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6878 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6935 __mutex_lock_common kernel/locking/mutex.c:679 [inline] __mutex_lock+0x6c7/0xb90 kernel/locking/mutex.c:747 blk_trace_startstop+0x7f/0x480 kernel/trace/blktrace.c:700 blk_trace_ioctl+0x1b5/0x280 kernel/trace/blktrace.c:742 blkdev_common_ioctl+0x176a/0x2480 block/ioctl.c:629 blkdev_ioctl+0x1cb/0x6d0 block/ioctl.c:698 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl fs/ioctl.c:893 [inline] __x64_sys_ioctl+0x18b/0x210 fs/ioctl.c:893 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f475718e929 RSP: 002b:00007f4757f8b038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f47573b6240 RCX: 00007f475718e929 RDX: 0000000000000000 RSI: 0000000000001274 RDI: 0000000000000003 RBP: 00007f4757210b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f47573b6240 R15: 00007ffcb45d2838 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e5c4880 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e5c4880 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e5c4880 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6770 3 locks held by klogd/5184: 2 locks held by getty/5585: #0: ffff8880329070a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222 2 locks held by syz.1.213/6699: 1 lock held by syz.1.213/6707: #0: ffff888026bce128 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_startstop+0x7f/0x480 kernel/trace/blktrace.c:700 2 locks held by syz.0.628/8389: #0: ffffffff9034d228 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:633 [inline] #0: ffffffff9034d228 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x38/0x230 drivers/net/tun.c:3396 #1: ffffffff8e5cfe78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x1a3/0x3c0 kernel/rcu/tree_exp.h:336 2 locks held by syz.2.630/8393: #0: ffff88805829b208 (&sb->s_type->i_mutex_key#11){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:869 [inline] #0: ffff88805829b208 (&sb->s_type->i_mutex_key#11){+.+.}-{4:4}, at: __sock_release+0x86/0x270 net/socket.c:646 #1: ffffffff8e5cfe78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x1a3/0x3c0 kernel/rcu/tree_exp.h:336 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-rc2-syzkaller-00082-gfb4d33ab452e #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x29c/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+0xf70/0x12c0 kernel/hung_task.c:470 kthread+0x3c2/0x780 kernel/kthread.c:464 ret_from_fork+0x5d4/0x6f0 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: 1156 Comm: kworker/u8:7 Not tainted 6.16.0-rc2-syzkaller-00082-gfb4d33ab452e #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Workqueue: bat_events batadv_nc_worker RIP: 0010:check_preemption_disabled+0x24/0xe0 lib/smp_processor_id.c:56 Code: 90 90 90 90 90 90 41 54 55 53 48 83 ec 08 65 8b 1d 85 bc 4c 08 65 8b 05 7a bc 4c 08 a9 ff ff ff 7f 74 0f 48 83 c4 08 89 d8 5b <5d> 41 5c e9 94 de 02 00 9c 58 f6 c4 02 74 ea 48 89 fd 65 48 8b 05 RSP: 0018:ffffc9000403fa28 EFLAGS: 00000292 RAX: 0000000000000000 RBX: ffff888035485f58 RCX: ffffffff8198c6bc RDX: ffff88802860c880 RSI: ffffffff8c157960 RDI: ffffffff8c1579a0 RBP: dffffc0000000000 R08: 0000000000000001 R09: fffff52000807f48 R10: 0000000000000003 R11: 0000000000000001 R12: ffffffff8b4d2294 R13: ffff888035485f40 R14: ffff88802583cd80 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888124753000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005600d0448c70 CR3: 00000000260b7000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline] rcu_is_watching+0x12/0xc0 kernel/rcu/tree.c:745 trace_lock_release include/trace/events/lock.h:69 [inline] lock_release+0x201/0x2f0 kernel/locking/lockdep.c:5882 __raw_spin_unlock_bh include/linux/spinlock_api_smp.h:165 [inline] _raw_spin_unlock_bh+0x16/0x30 kernel/locking/spinlock.c:210 spin_unlock_bh include/linux/spinlock.h:396 [inline] batadv_nc_purge_paths+0x1d4/0x3a0 net/batman-adv/network-coding.c:471 batadv_nc_worker+0x921/0x1030 net/batman-adv/network-coding.c:720 process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3321 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3402 kthread+0x3c2/0x780 kernel/kthread.c:464 ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 vkms_vblank_simulate: vblank timer overrun sctp: sctp_transport_update_pmtu: Reported pmtu 68 too low, using default minimum of 512