INFO: task syz.0.2127:12827 blocked for more than 143 seconds. Not tainted 6.16.0-rc5-syzkaller-00276-g5d5d62298b8b #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.2127 state:D stack:28904 pid:12827 tgid:12824 ppid:5866 task_flags:0x400040 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5397 [inline] __schedule+0x16f5/0x4d00 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 __mutex_lock_common kernel/locking/mutex.c:679 [inline] __mutex_lock+0x724/0xe80 kernel/locking/mutex.c:747 blk_trace_remove kernel/trace/blktrace.c:406 [inline] blk_trace_ioctl+0x1b9/0x430 kernel/trace/blktrace.c:745 blkdev_common_ioctl+0xdce/0x2450 block/ioctl.c:629 blkdev_ioctl+0x4ef/0x6d0 block/ioctl.c:698 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:893 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: 0033:0x7fb15c38e929 RSP: 002b:00007fb15d180038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fb15c5b6080 RCX: 00007fb15c38e929 RDX: 0000000000000000 RSI: 0000000000001276 RDI: 0000000000000003 RBP: 00007fb15c410b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000001 R14: 00007fb15c5b6080 R15: 00007fb15c6dfa28 Showing all locks held in the system: 4 locks held by kworker/u8:1/13: 3 locks held by kworker/1:0/24: #0: ffff88801a480d48 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff88801a480d48 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3321 #1: ffffc900001e7bc0 (free_ipc_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc900001e7bc0 (free_ipc_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3321 #2: ffff8880b8639f98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xad/0x140 kernel/sched/core.c:614 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 3 locks held by kworker/1:2/119: 5 locks held by kworker/u8:5/1099: 2 locks held by getty/5613: #0: ffff888030c6d0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332e2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 4 locks held by kworker/u8:8/8506: 2 locks held by syz.0.2127/12826: 1 lock held by syz.0.2127/12827: #0: ffff8881437f43d0 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_remove kernel/trace/blktrace.c:406 [inline] #0: ffff8881437f43d0 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_ioctl+0x1b9/0x430 kernel/trace/blktrace.c:745 2 locks held by syz.5.2166/13022: #0: ffff8881437f6128 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_setup+0xfb/0x1f0 kernel/trace/blktrace.c:631 #1: ffffffff8e1931e8 (relay_channels_mutex){+.+.}-{4:4}, at: relay_open+0x3b8/0x920 kernel/relay.c:510 1 lock held by syz.6.2386/13885: 2 locks held by syz.4.2501/14255: #0: ffff888143be4d98 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_setup+0xfb/0x1f0 kernel/trace/blktrace.c:631 #1: ffffffff8e1931e8 (relay_channels_mutex){+.+.}-{4:4}, at: relay_open+0x3b8/0x920 kernel/relay.c:510 1 lock held by syz.3.2559/14478: #0: ffffffff8e144bf8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:336 [inline] #0: ffffffff8e144bf8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730 kernel/rcu/tree_exp.h:998 1 lock held by syz.7.2563/14489: #0: ffffffff8f51da08 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:633 [inline] #0: ffffffff8f51da08 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3396 1 lock held by syz.2.2562/14485: #0: ffffffff8f51da08 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:633 [inline] #0: ffffffff8f51da08 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3396 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-rc5-syzkaller-00276-g5d5d62298b8b #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 1099 Comm: kworker/u8:5 Not tainted 6.16.0-rc5-syzkaller-00276-g5d5d62298b8b #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:__lock_acquire+0x304/0xd20 kernel/locking/lockdep.c:5182 Code: e2 0f 0f b7 d2 09 f2 41 83 e4 03 41 c1 e4 10 41 09 d4 8b 54 24 0c 83 e2 01 c1 e2 12 44 09 e2 41 c1 e6 14 41 09 d6 8b 54 24 10 e2 13 c1 e5 15 09 d5 09 cd 44 09 f5 41 89 6c c7 20 45 89 44 c7 RSP: 0018:ffffc90003d2f8f0 EFLAGS: 00000006 RAX: 000000000000000a RBX: ffffffff8e13f0e0 RCX: 0000000000000007 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff888026d58000 RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff8b3d1432 R10: dffffc0000000000 R11: ffffffff8b3d1360 R12: 0000000000020000 R13: 0000000000000000 R14: 0000000000020000 R15: ffff888026d58af0 FS: 0000000000000000(0000) GS:ffff888125c1b000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fb15c38e8ff CR3: 000000000df38000 CR4: 00000000003526f0 Call Trace: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5871 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:841 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline] batadv_nc_worker+0xef/0x610 net/batman-adv/network-coding.c:719 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xae1/0x17b0 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