INFO: task hwrng:751 blocked for more than 143 seconds. Not tainted 6.7.0-rc5-syzkaller-00030-geaadbbaaff74 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:hwrng state:D stack:27408 pid:751 tgid:751 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5376 [inline] __schedule+0x1961/0x4ab0 kernel/sched/core.c:6688 __schedule_loop kernel/sched/core.c:6763 [inline] schedule+0x149/0x260 kernel/sched/core.c:6778 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6835 __mutex_lock_common kernel/locking/mutex.c:679 [inline] __mutex_lock+0x6a3/0xd60 kernel/locking/mutex.c:747 hwrng_fillfn+0xe6/0x3c0 drivers/char/hw_random/core.c:504 kthread+0x2d3/0x370 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242 Showing all locks held in the system: 1 lock held by khungtaskd/29: #0: ffffffff8d92e060 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:301 [inline] #0: ffffffff8d92e060 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:747 [inline] #0: ffffffff8d92e060 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6614 1 lock held by hwrng/751: #0: ffffffff8e0e1a08 (reading_mutex){+.+.}-{3:3}, at: hwrng_fillfn+0xe6/0x3c0 drivers/char/hw_random/core.c:504 2 locks held by getty/4808: #0: ffff888026abc0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900031332f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6b4/0x1e10 drivers/tty/n_tty.c:2201 4 locks held by syz-executor.3/1536: 1 lock held by syz-executor.3/1744: 1 lock held by syz-executor.3/1911: 2 locks held by syz-executor.3/2041: 1 lock held by syz-executor.3/2152: 1 lock held by syz-executor.3/2297: ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 29 Comm: khungtaskd Not tainted 6.7.0-rc5-syzkaller-00030-geaadbbaaff74 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/10/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e7/0x2d0 lib/dump_stack.c:106 nmi_cpu_backtrace+0x498/0x4d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x198/0x310 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline] watchdog+0xfaf/0xff0 kernel/hung_task.c:379 kthread+0x2d3/0x370 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 11840 Comm: kworker/u4:1 Not tainted 6.7.0-rc5-syzkaller-00030-geaadbbaaff74 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/10/2023 Workqueue: bat_events batadv_nc_worker RIP: 0010:hlock_class kernel/locking/lockdep.c:223 [inline] RIP: 0010:mark_lock+0x61/0x350 kernel/locking/lockdep.c:4656 Code: 85 86 02 00 00 31 ed f6 43 02 03 40 0f 94 c5 83 f5 09 eb 0b 89 d5 83 fa 20 0f 83 d5 02 00 00 41 be 01 00 00 00 89 e9 41 d3 e6 <49> 8d 5f 20 48 89 d8 48 c1 e8 03 42 0f b6 04 28 84 c0 0f 85 2c 02 RSP: 0018:ffffc900147b78e8 EFLAGS: 00000006 RAX: 0000000000000000 RBX: ffff8880258f28f0 RCX: 0000000000000009 RDX: 0000000000000008 RSI: ffff8880258f28d0 RDI: ffff8880258f1dc0 RBP: 0000000000000009 R08: ffffffff90dd943f R09: 1ffffffff21bb287 R10: dffffc0000000000 R11: fffffbfff21bb288 R12: 0000000000000000 R13: dffffc0000000000 R14: 0000000000000200 R15: ffff8880258f28d0 FS: 0000000000000000(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000c0001ad000 CR3: 000000000d731000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: mark_usage kernel/locking/lockdep.c:4599 [inline] __lock_acquire+0xc09/0x1fd0 kernel/locking/lockdep.c:5091 lock_acquire+0x1e3/0x530 kernel/locking/lockdep.c:5754 rcu_lock_acquire include/linux/rcupdate.h:301 [inline] rcu_read_lock include/linux/rcupdate.h:747 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline] batadv_nc_worker+0xec/0x610 net/batman-adv/network-coding.c:719 process_one_work kernel/workqueue.c:2627 [inline] process_scheduled_works+0x90f/0x1420 kernel/workqueue.c:2700 worker_thread+0xa5f/0x1000 kernel/workqueue.c:2781 kthread+0x2d3/0x370 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242