binder: release 21166:21169 transaction 29 in, still active binder: send failed reply for transaction 29 to 21166:21169 binder: undelivered TRANSACTION_COMPLETE binder: undelivered TRANSACTION_ERROR: 29201 binder: undelivered TRANSACTION_ERROR: 29189 INFO: task kworker/u4:6:5069 blocked for more than 120 seconds. Not tainted 4.9.109-ge7fd5b1 #1 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/u4:6 D25544 5069 2 0x00000000 Workqueue: events_unbound flush_to_ldisc ffff880177464800 0000000000000000 ffff8801d453ef40 ffff8801d84ce000 ffff8801db221c18 ffff8801c44778c8 ffffffff839e8a8d ffff8801774650c8 ffffed002ee8ca18 ffff880177464800 00fffc0000000000 ffff8801db2224e8 Call Trace: [] schedule+0x7f/0x1b0 kernel/sched/core.c:3557 [] schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3590 [] __mutex_lock_common kernel/locking/mutex.c:582 [inline] [] mutex_lock_nested+0x326/0x870 kernel/locking/mutex.c:621 [] commit_echoes+0x120/0x1b0 drivers/tty/n_tty.c:764 [] n_tty_receive_char_fast drivers/tty/n_tty.c:1418 [inline] [] n_tty_receive_buf_fast drivers/tty/n_tty.c:1578 [inline] [] __receive_buf drivers/tty/n_tty.c:1613 [inline] [] n_tty_receive_buf_common+0x1878/0x2300 drivers/tty/n_tty.c:1711 [] n_tty_receive_buf2+0x33/0x40 drivers/tty/n_tty.c:1746 [] tty_ldisc_receive_buf+0xaf/0x190 drivers/tty/tty_buffer.c:455 [] receive_buf drivers/tty/tty_buffer.c:474 [inline] [] flush_to_ldisc+0x253/0x370 drivers/tty/tty_buffer.c:533 [] process_one_work+0x7e1/0x1500 kernel/workqueue.c:2092 [] worker_thread+0xd6/0x10a0 kernel/workqueue.c:2226 [] kthread+0x26d/0x300 kernel/kthread.c:211 [] ret_from_fork+0x5c/0x70 arch/x86/entry/entry_64.S:373 Showing all locks held in the system: 2 locks held by khungtaskd/520: #0: (rcu_read_lock){......}, at: [] check_hung_uninterruptible_tasks kernel/hung_task.c:168 [inline] #0: (rcu_read_lock){......}, at: [] watchdog+0x11c/0xa20 kernel/hung_task.c:239 #1: (tasklist_lock){.+.+..}, at: [] debug_show_all_locks+0x79/0x218 kernel/locking/lockdep.c:4336 2 locks held by getty/3649: #0: (&tty->ldisc_sem){++++++}, at: [] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367 #1: (&ldata->atomic_read_lock){+.+...}, at: [] n_tty_read+0x202/0x16e0 drivers/tty/n_tty.c:2133 6 locks held by kworker/u4:6/5069: #0: ("events_unbound"){.+.+.+}, at: [] work_static include/linux/workqueue.h:186 [inline] #0: ("events_unbound"){.+.+.+}, at: [] set_work_data kernel/workqueue.c:617 [inline] #0: ("events_unbound"){.+.+.+}, at: [] set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline] #0: ("events_unbound"){.+.+.+}, at: [] process_one_work+0x6ee/0x1500 kernel/workqueue.c:2085 #1: ((&buf->work)){+.+...}, at: [] process_one_work+0x728/0x1500 kernel/workqueue.c:2089 #2: (&tty->ldisc_sem){++++++}, at: [] tty_ldisc_ref+0x20/0x80 drivers/tty/tty_ldisc.c:296 #3: (&port->buf.lock/1){+.+...}, at: [] flush_to_ldisc+0x86/0x370 drivers/tty/tty_buffer.c:505 #4: (&o_tty->termios_rwsem/1){++++..}, at: [] n_tty_receive_buf_common+0x8b/0x2300 drivers/tty/n_tty.c:1674 #5: (&ldata->output_lock){+.+...}, at: [] commit_echoes+0x120/0x1b0 drivers/tty/n_tty.c:764 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 520 Comm: khungtaskd Not tainted 4.9.109-ge7fd5b1 #1 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ffff8801d90f7d08 ffffffff81eb3e29 0000000000000000 0000000000000000 0000000000000000 0000000000000001 ffffffff810b9580 ffff8801d90f7d40 ffffffff81ebf127 0000000000000000 0000000000000000 0000000000000002 Call Trace: [] __dump_stack lib/dump_stack.c:15 [inline] [] dump_stack+0xc1/0x128 lib/dump_stack.c:51 [] nmi_cpu_backtrace.cold.2+0x48/0x87 lib/nmi_backtrace.c:99 [] nmi_trigger_cpumask_backtrace+0x12a/0x14f lib/nmi_backtrace.c:60 [] arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:37 [] trigger_all_cpu_backtrace include/linux/nmi.h:58 [inline] [] check_hung_task kernel/hung_task.c:125 [inline] [] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline] [] watchdog+0x6b4/0xa20 kernel/hung_task.c:239 [] kthread+0x26d/0x300 kernel/kthread.c:211 [] ret_from_fork+0x5c/0x70 arch/x86/entry/entry_64.S:373 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 21173 Comm: syz-executor7 Not tainted 4.9.109-ge7fd5b1 #1 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff8801cd151800 task.stack: ffff880178c40000 RIP: 0010:[] c [] __sanitizer_cov_trace_pc+0x1e/0x50 kernel/kcov.c:96 RSP: 0018:ffff880178c47898 EFLAGS: 00000246 RAX: ffff8801cd151800 RBX: ffffc9001126a000 RCX: ffffc90005ed8000 RDX: 0000000000000000 RSI: ffffffff8211bb8f RDI: ffffc9001126b38a RBP: ffff880178c47898 R08: ffff8801cd152138 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 00000005e678012b R13: 00000000000044f0 R14: dffffc0000000000 R15: 00000005e678012b FS: 00007f24796a5700(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000c450b7c098 CR3: 0000000186c09000 CR4: 00000000001606f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Stack: ffff880178c47910c ffffffff8211bb8fc 0000000000000000c ffff8801cd1520b4c ffffc9001126c278c ffffed003ada0185c ffff8801d6d00c2cc ffffc9001126a020c 0000000000000400c ffff8801d6d00880c ffffc9001126a000c ffff8801d6d00880c Call Trace: [] echo_buf drivers/tty/n_tty.c:146 [inline] [] __process_echoes+0x5cf/0x780 drivers/tty/n_tty.c:734 [] commit_echoes+0x147/0x1b0 drivers/tty/n_tty.c:766 [] n_tty_receive_char_special+0xd64/0x2860 drivers/tty/n_tty.c:1286 [] n_tty_receive_buf_fast drivers/tty/n_tty.c:1579 [inline] [] __receive_buf drivers/tty/n_tty.c:1613 [inline] [] n_tty_receive_buf_common+0x18ea/0x2300 drivers/tty/n_tty.c:1711 [] n_tty_receive_buf+0x30/0x40 drivers/tty/n_tty.c:1740 [] tiocsti drivers/tty/tty_io.c:2314 [inline] [] tty_ioctl+0xc8f/0x2270 drivers/tty/tty_io.c:2905 [] vfs_ioctl fs/ioctl.c:43 [inline] [] file_ioctl fs/ioctl.c:493 [inline] [] do_vfs_ioctl+0x1ac/0x11a0 fs/ioctl.c:677 [] SYSC_ioctl fs/ioctl.c:694 [inline] [] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:685 [] do_syscall_64+0x1a6/0x490 arch/x86/entry/common.c:282 [] entry_SYSCALL_64_after_swapgs+0x5d/0xdb Code: c66 c2e c0f c1f c84 c00 c00 c00 c00 c00 c0f c1f c00 c55 c48 c89 ce5 c65 c48 c8b c04 c25 cc0 c7d c01 c00 c65 c8b c15 cfc c93 ccb c7e c81 ce2 c00 c01 c1f c00 c48 c8b c75 c08 c<75> c2b c8b c90 c80 c12 c00 c00 c83 cfa c02 c75 c20 c48 c8b c88 c88 c12 c00 c00 c8b c