INFO: task syz-executor483:7934 blocked for more than 143 seconds. Not tainted 5.1.0-rc5-next-20190418 #28 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor483 D23720 7934 7933 0x00000000 Call Trace: context_switch kernel/sched/core.c:2817 [inline] __schedule+0x7d1/0x15c0 kernel/sched/core.c:3444 schedule+0xa8/0x260 kernel/sched/core.c:3508 __rwsem_down_read_failed_common kernel/locking/rwsem-xadd.c:479 [inline] rwsem_down_read_failed+0x213/0x460 kernel/locking/rwsem-xadd.c:499 __down_read kernel/locking/rwsem.h:177 [inline] down_read+0xa5/0x1a0 kernel/locking/rwsem.c:26 do_user_addr_fault arch/x86/mm/fault.c:1427 [inline] __do_page_fault+0x9e9/0xda0 arch/x86/mm/fault.c:1542 do_page_fault+0x71/0x581 arch/x86/mm/fault.c:1573 page_fault+0x1e/0x30 arch/x86/entry/entry_64.S:1142 RIP: 0033:0x4aeb50 Code: Bad RIP value. RSP: 002b:00007ffd892b5808 EFLAGS: 00010206 RAX: 00000000004aeb50 RBX: 0000000000000001 RCX: 00000000006e47b0 RDX: 0000000000409e20 RSI: 0000000000000001 RDI: 00000000004d0470 RBP: 00007ffd892b5810 R08: 00007ffd892b5d09 R09: 00007ffd892b5d09 R10: 00007ffd892b5890 R11: 0000000000000000 R12: 0000000000000001 R13: 00000000006e47a0 R14: 000000000000002d R15: 0000000000000006 Showing all locks held in the system: 1 lock held by khungtaskd/1043: #0: 0000000094fd50cd (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x27e kernel/locking/lockdep.c:5046 3 locks held by rs:main Q:Reg/7818: #0: 000000009de82e2c (&rq->lock){-.-.}, at: rq_lock kernel/sched/sched.h:1168 [inline] #0: 000000009de82e2c (&rq->lock){-.-.}, at: __schedule+0x1f5/0x15c0 kernel/sched/core.c:3396 #1: 0000000094fd50cd (rcu_read_lock){....}, at: file_start_write include/linux/fs.h:2825 [inline] #1: 0000000094fd50cd (rcu_read_lock){....}, at: vfs_write+0x429/0x580 fs/read_write.c:548 #2: 000000009e84d141 (&sb->s_type->i_mutex_key#10){+.+.}, at: inode_trylock include/linux/fs.h:792 [inline] #2: 000000009e84d141 (&sb->s_type->i_mutex_key#10){+.+.}, at: ext4_file_write_iter+0x257/0x11c0 fs/ext4/file.c:232 1 lock held by rsyslogd/7820: #0: 00000000e9d702ac (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:801 2 locks held by getty/7911: #0: 000000007b03ef87 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000008a1b8e3f (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7912: #0: 000000001b88eeb0 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000bf3e0004 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7913: #0: 00000000b713aa93 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000e920f7f2 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7914: #0: 00000000338a9170 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000765055aa (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7915: #0: 00000000e3b3e84c (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000f0c96d15 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7916: #0: 00000000fa9a42ff (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 0000000003f8d2e2 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7917: #0: 000000002f77ac70 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000007de33b6e (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 1 lock held by syz-executor483/7934: #0: 00000000d53d7946 (&mm->mmap_sem){++++}, at: do_user_addr_fault arch/x86/mm/fault.c:1427 [inline] #0: 00000000d53d7946 (&mm->mmap_sem){++++}, at: __do_page_fault+0x9e9/0xda0 arch/x86/mm/fault.c:1542 1 lock held by syz-executor483/7943: ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1043 Comm: khungtaskd Not tainted 5.1.0-rc5-next-20190418 #28 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:204 [inline] watchdog+0x9b7/0xec0 kernel/hung_task.c:288 kthread+0x357/0x430 kernel/kthread.c:254 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 Sending NMI from CPU 1 to CPUs 0: