INFO: task syz.5.22:6360 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.5.22 state:D stack:29000 pid:6360 tgid:6358 ppid:6329 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5298 [inline] __schedule+0xfee/0x6120 kernel/sched/core.c:6911 __schedule_loop kernel/sched/core.c:6993 [inline] schedule+0xdd/0x390 kernel/sched/core.c:7008 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7065 __mutex_lock_common kernel/locking/mutex.c:692 [inline] __mutex_lock+0xc9a/0x1b90 kernel/locking/mutex.c:776 blk_debugfs_lock_nomemsave block/blk.h:740 [inline] blk_trace_remove kernel/trace/blktrace.c:561 [inline] blk_trace_ioctl+0x263/0x320 kernel/trace/blktrace.c:952 blkdev_common_ioctl+0x170c/0x2ba0 block/ioctl.c:724 blkdev_ioctl+0x43b/0x6f0 block/ioctl.c:798 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl fs/ioctl.c:583 [inline] __x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f02f179c799 RSP: 002b:00007f02f2592028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f02f1a16090 RCX: 00007f02f179c799 RDX: 0000000000000000 RSI: 0000000000001276 RDI: 0000000000000003 RBP: 00007f02f1832c99 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f02f1a16128 R14: 00007f02f1a16090 R15: 00007ffeaa8d5c08 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e7e7660 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8e7e7660 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8e7e7660 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775 2 locks held by getty/5586: #0: ffff8880383990a0 (&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+0x419/0x1500 drivers/tty/n_tty.c:2211 2 locks held by syz.5.22/6359: 1 lock held by syz.5.22/6360: #0: ffff88802748af00 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock_nomemsave block/blk.h:740 [inline] #0: ffff88802748af00 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_remove kernel/trace/blktrace.c:561 [inline] #0: ffff88802748af00 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_ioctl+0x263/0x320 kernel/trace/blktrace.c:952 1 lock held by syz.6.23/6447: #0: ffff88802748af00 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock_nomemsave block/blk.h:740 [inline] #0: ffff88802748af00 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock block/blk.h:752 [inline] #0: ffff88802748af00 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_setup+0x1f2/0x440 kernel/trace/blktrace.c:788 1 lock held by syz.6.23/6448: #0: ffff88802748af00 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock_nomemsave block/blk.h:740 [inline] #0: ffff88802748af00 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_remove kernel/trace/blktrace.c:561 [inline] #0: ffff88802748af00 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_ioctl+0x263/0x320 kernel/trace/blktrace.c:952 1 lock held by syz.7.24/6478: #0: ffff88802748af00 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock_nomemsave block/blk.h:740 [inline] #0: ffff88802748af00 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock block/blk.h:752 [inline] #0: ffff88802748af00 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_setup+0x1f2/0x440 kernel/trace/blktrace.c:788 1 lock held by syz.7.24/6481: #0: ffff88802748af00 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock_nomemsave block/blk.h:740 [inline] #0: ffff88802748af00 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_remove kernel/trace/blktrace.c:561 [inline] #0: ffff88802748af00 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_ioctl+0x263/0x320 kernel/trace/blktrace.c:952 1 lock held by syz.8.25/6644: #0: ffff88802748af00 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock_nomemsave block/blk.h:740 [inline] #0: ffff88802748af00 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock block/blk.h:752 [inline] #0: ffff88802748af00 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_setup+0x1f2/0x440 kernel/trace/blktrace.c:788 1 lock held by syz.8.25/6645: #0: ffff88802748af00 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock_nomemsave block/blk.h:740 [inline] #0: ffff88802748af00 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_remove kernel/trace/blktrace.c:561 [inline] #0: ffff88802748af00 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_ioctl+0x263/0x320 kernel/trace/blktrace.c:952 1 lock held by syz.9.26/6675: #0: ffff88802748af00 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock_nomemsave block/blk.h:740 [inline] #0: ffff88802748af00 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock block/blk.h:752 [inline] #0: ffff88802748af00 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_setup+0x1f2/0x440 kernel/trace/blktrace.c:788 1 lock held by syz.9.26/6676: #0: ffff88802748af00 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock_nomemsave block/blk.h:740 [inline] #0: ffff88802748af00 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_remove kernel/trace/blktrace.c:561 [inline] #0: ffff88802748af00 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_ioctl+0x263/0x320 kernel/trace/blktrace.c:952 1 lock held by syz.0.27/6799: #0: ffff88802748af00 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock_nomemsave block/blk.h:740 [inline] #0: ffff88802748af00 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock block/blk.h:752 [inline] #0: ffff88802748af00 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_setup+0x1f2/0x440 kernel/trace/blktrace.c:788 1 lock held by syz.0.27/6800: #0: ffff88802748af00 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock_nomemsave block/blk.h:740 [inline] #0: ffff88802748af00 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_remove kernel/trace/blktrace.c:561 [inline] #0: ffff88802748af00 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_ioctl+0x263/0x320 kernel/trace/blktrace.c:952 1 lock held by syz.1.28/7059: #0: ffff88802748af00 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock_nomemsave block/blk.h:740 [inline] #0: ffff88802748af00 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock block/blk.h:752 [inline] #0: ffff88802748af00 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_setup+0x1f2/0x440 kernel/trace/blktrace.c:788 1 lock held by syz.1.28/7060: #0: ffff88802748af00 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock_nomemsave block/blk.h:740 [inline] #0: ffff88802748af00 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_remove kernel/trace/blktrace.c:561 [inline] #0: ffff88802748af00 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_ioctl+0x263/0x320 kernel/trace/blktrace.c:952 1 lock held by syz.2.29/7250: #0: ffff88802748af00 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock_nomemsave block/blk.h:740 [inline] #0: ffff88802748af00 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock block/blk.h:752 [inline] #0: ffff88802748af00 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_setup+0x1f2/0x440 kernel/trace/blktrace.c:788 1 lock held by syz.2.29/7252: #0: ffff88802748af00 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock_nomemsave block/blk.h:740 [inline] #0: ffff88802748af00 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_remove kernel/trace/blktrace.c:561 [inline] #0: ffff88802748af00 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_ioctl+0x263/0x320 kernel/trace/blktrace.c:952 1 lock held by syz.3.30/7521: #0: ffff88802748af00 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock_nomemsave block/blk.h:740 [inline] #0: ffff88802748af00 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock block/blk.h:752 [inline] #0: ffff88802748af00 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_setup+0x1f2/0x440 kernel/trace/blktrace.c:788 1 lock held by syz.3.30/7522: #0: ffff88802748af00 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock_nomemsave block/blk.h:740 [inline] #0: ffff88802748af00 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_remove kernel/trace/blktrace.c:561 [inline] #0: ffff88802748af00 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_ioctl+0x263/0x320 kernel/trace/blktrace.c:952 1 lock held by dhcpcd-run-hook/7664: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120 nmi_cpu_backtrace.cold+0x12d/0x151 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x1d7/0x230 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:161 [inline] __sys_info lib/sys_info.c:157 [inline] sys_info+0x141/0x190 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline] watchdog+0xd25/0x1050 kernel/hung_task.c:515 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158 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: 13 Comm: kworker/u8:1 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Workqueue: bat_events batadv_iv_send_outstanding_bat_ogm_packet RIP: 0010:__kasan_check_byte+0x1c/0x50 mm/kasan/common.c:578 Code: 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1f 40 d6 41 54 49 89 f4 55 48 89 fd 53 e8 4d 20 00 00 89 c3 84 c0 74 0b 89 d8 5b <5d> 41 5c e9 0c 21 1d 09 4c 89 e1 48 89 ef 31 d2 be 01 00 00 00 e8 RSP: 0018:ffffc90000127a18 EFLAGS: 00000202 RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0000000000000002 RDX: 0000000000000000 RSI: ffffffff8b55ad8a RDI: fffffbfff1cfcecc RBP: ffffffff8e7e7660 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000400 R11: 0000000000000000 R12: ffffffff8b55ad8a R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888124449000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f096e1d1318 CR3: 000000000e598000 CR4: 00000000003526f0 Call Trace: kasan_check_byte include/linux/kasan.h:402 [inline] lock_acquire kernel/locking/lockdep.c:5842 [inline] lock_acquire+0x148/0x380 kernel/locking/lockdep.c:5825 rcu_lock_acquire include/linux/rcupdate.h:312 [inline] rcu_read_lock include/linux/rcupdate.h:850 [inline] batadv_iv_ogm_slide_own_bcast_window net/batman-adv/bat_iv_ogm.c:764 [inline] batadv_iv_ogm_schedule_buff+0x5da/0x1520 net/batman-adv/bat_iv_ogm.c:836 batadv_iv_ogm_schedule net/batman-adv/bat_iv_ogm.c:876 [inline] batadv_iv_ogm_schedule net/batman-adv/bat_iv_ogm.c:869 [inline] batadv_iv_send_outstanding_bat_ogm_packet+0x6e0/0x860 net/batman-adv/bat_iv_ogm.c:1712 process_one_work+0xa23/0x19a0 kernel/workqueue.c:3276 process_scheduled_works kernel/workqueue.c:3359 [inline] worker_thread+0x5ef/0xe50 kernel/workqueue.c:3440 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245