INFO: task syz-executor4:12659 blocked for more than 140 seconds. Not tainted 5.0.0-rc5+ #61 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor4 D24448 12659 1 0x80000004 Call Trace: context_switch kernel/sched/core.c:2844 [inline] __schedule+0x817/0x1cc0 kernel/sched/core.c:3485 schedule+0x92/0x180 kernel/sched/core.c:3529 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3587 __mutex_lock_common kernel/locking/mutex.c:1002 [inline] __mutex_lock+0x726/0x1310 kernel/locking/mutex.c:1072 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087 acct_get kernel/acct.c:161 [inline] slow_acct_process kernel/acct.c:577 [inline] acct_process+0x2e5/0x61e kernel/acct.c:605 do_exit+0x17df/0x2fd0 kernel/exit.c:865 do_group_exit+0x135/0x370 kernel/exit.c:979 get_signal+0x766/0x1750 kernel/signal.c:2517 do_signal+0x87/0x1940 arch/x86/kernel/signal.c:816 exit_to_usermode_loop+0x244/0x2c0 arch/x86/entry/common.c:162 prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline] syscall_return_slowpath arch/x86/entry/common.c:268 [inline] do_syscall_64+0x52d/0x610 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x411fca Code: 22 41 00 e9 a6 fe ff ff be 4c 37 44 00 48 89 ef e8 1b 94 ff ff 85 c0 75 0c 48 c7 03 f0 22 41 00 e9 89 fe ff ff 31 c0 48 89 ee 30 31 44 00 e8 5c f0 00 00 b8 14 fc ff ff e9 72 fe ff ff 66 90 RSP: 002b:00007fffed90d388 EFLAGS: 00000246 ORIG_RAX: 000000000000003d RAX: fffffffffffffe00 RBX: 000000000226d99b RCX: 0000000000411fca RDX: 0000000040000000 RSI: 00007fffed90d3c0 RDI: ffffffffffffffff RBP: 00000000000002e6 R08: 0000000000000001 R09: 0000000000000001 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000226d940 R13: 000000000013c621 R14: 00000000000000f7 R15: 0000000000000004 Showing all locks held in the system: 1 lock held by khungtaskd/1039: #0: 0000000050ca70b8 (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x27e kernel/locking/lockdep.c:4389 1 lock held by rsyslogd/7613: #0: 0000000067d8dfe1 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:795 2 locks held by getty/7703: #0: 00000000685c66ae (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000006f13d52d (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154 2 locks held by getty/7704: #0: 00000000c49c7cef (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000482638ae (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154 2 locks held by getty/7705: #0: 0000000043bdddb3 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000249d364e (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154 2 locks held by getty/7706: #0: 000000001676fe0c (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000009d4b947c (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154 2 locks held by getty/7707: #0: 00000000a07942ed (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000b94964f5 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154 2 locks held by getty/7708: #0: 000000004de12a90 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000db17f5b0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154 2 locks held by getty/7709: #0: 00000000887e49b7 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 0000000075e99210 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154 1 lock held by syz-executor4/12659: #0: 00000000bc5d9bdd (&acct->lock#2){+.+.}, at: acct_get kernel/acct.c:161 [inline] #0: 00000000bc5d9bdd (&acct->lock#2){+.+.}, at: slow_acct_process kernel/acct.c:577 [inline] #0: 00000000bc5d9bdd (&acct->lock#2){+.+.}, at: acct_process+0x2e5/0x61e kernel/acct.c:605 3 locks held by syz-executor4/20065: #0: 00000000bc5d9bdd (&acct->lock#2){+.+.}, at: acct_get kernel/acct.c:161 [inline] #0: 00000000bc5d9bdd (&acct->lock#2){+.+.}, at: slow_acct_process kernel/acct.c:577 [inline] #0: 00000000bc5d9bdd (&acct->lock#2){+.+.}, at: acct_process+0x2e5/0x61e kernel/acct.c:605 #1: 000000007221561f (sb_writers#3){.+.+}, at: file_start_write_trylock include/linux/fs.h:2823 [inline] #1: 000000007221561f (sb_writers#3){.+.+}, at: do_acct_process+0xf37/0x1150 kernel/acct.c:517 #2: 00000000f0d6a108 (&sb->s_type->i_mutex_key#10){++++}, at: inode_trylock include/linux/fs.h:777 [inline] #2: 00000000f0d6a108 (&sb->s_type->i_mutex_key#10){++++}, at: ext4_file_write_iter+0x250/0x1160 fs/ext4/file.c:232 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1039 Comm: khungtaskd Not tainted 5.0.0-rc5+ #61 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x172/0x1f0 lib/dump_stack.c:113 nmi_cpu_backtrace.cold+0x63/0xa4 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1be/0x236 lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:203 [inline] watchdog+0x9df/0xee0 kernel/hung_task.c:287 kthread+0x357/0x430 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 9274 Comm: kworker/u4:7 Not tainted 5.0.0-rc5+ #61 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: bat_events batadv_nc_worker RIP: 0010:check_preemption_disabled+0x4/0x290 lib/smp_processor_id.c:12 Code: ff ff e8 2f 21 18 fe 48 8b bd 18 ff ff ff e8 93 d2 7b fe e9 6a ec ff ff e8 29 d3 7b fe e9 28 f1 ff ff 90 90 90 90 55 48 89 e5 <41> 57 41 56 49 89 f6 41 55 41 54 49 89 fc 53 48 83 ec 08 e8 e4 d6 RSP: 0018:ffff88805f6dfc88 EFLAGS: 00000293 RAX: ffff88808c6f8500 RBX: 000000000002ddc0 RCX: ffffffff86e6dfc1 RDX: 0000000000000000 RSI: ffffffff87a242c0 RDI: ffffffff87a24300 RBP: ffff88805f6dfc88 R08: ffff88808c6f8500 R09: ffffed1015d05bd0 R10: ffffed1015d05bcf R11: ffff8880ae82de7b R12: 0000000000000001 R13: 0000000000000217 R14: 0000000000000000 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffff600400 CR3: 0000000098f87000 CR4: 00000000001426f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: debug_smp_processor_id+0x1c/0x20 lib/smp_processor_id.c:56 rcu_dynticks_curr_cpu_in_eqs+0x17/0xb0 kernel/rcu/tree.c:303 rcu_is_watching+0x10/0x30 kernel/rcu/tree.c:932 rcu_read_unlock include/linux/rcupdate.h:657 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:423 [inline] batadv_nc_worker+0x485/0x760 net/batman-adv/network-coding.c:730 process_one_work+0x98e/0x1790 kernel/workqueue.c:2173 worker_thread+0x98/0xe40 kernel/workqueue.c:2319 kthread+0x357/0x430 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352