INFO: task syz-executor074:4443 blocked for more than 120 seconds. Not tainted 4.17.0-rc2+ #23 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor074 D15176 4443 4440 0x00000000 Call Trace: context_switch kernel/sched/core.c:2848 [inline] __schedule+0x801/0x1e30 kernel/sched/core.c:3490 schedule+0xef/0x430 kernel/sched/core.c:3549 blk_queue_enter+0x8da/0xdf0 block/blk-core.c:953 generic_make_request+0x144/0x1510 block/blk-core.c:2395 blk_queue_split+0x374/0x2090 block/blk-merge.c:215 blk_mq_make_request+0x2d0/0x25c0 block/blk-mq.c:1845 generic_make_request+0x795/0x1510 block/blk-core.c:2460 submit_bio+0xba/0x460 block/blk-core.c:2568 mpage_bio_submit fs/mpage.c:66 [inline] mpage_readpages+0x6d7/0x970 fs/mpage.c:393 blkdev_readpages+0x2c/0x40 fs/block_dev.c:577 read_pages mm/readahead.c:121 [inline] __do_page_cache_readahead+0x79a/0xdc0 mm/readahead.c:199 ra_submit mm/internal.h:66 [inline] ondemand_readahead+0x550/0xc40 mm/readahead.c:478 page_cache_sync_readahead+0xd1/0x110 mm/readahead.c:510 generic_file_buffered_read mm/filemap.c:2092 [inline] generic_file_read_iter+0x1a74/0x2f00 mm/filemap.c:2362 blkdev_read_iter+0x120/0x190 fs/block_dev.c:1930 call_read_iter include/linux/fs.h:1778 [inline] generic_file_splice_read+0x552/0x910 fs/splice.c:307 do_splice_to+0x12e/0x190 fs/splice.c:880 splice_direct_to_actor+0x268/0x8d0 fs/splice.c:952 do_splice_direct+0x2cc/0x400 fs/splice.c:1061 do_sendfile+0x60f/0xe00 fs/read_write.c:1440 __do_sys_sendfile64 fs/read_write.c:1495 [inline] __se_sys_sendfile64 fs/read_write.c:1487 [inline] __x64_sys_sendfile64+0x155/0x240 fs/read_write.c:1487 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x449309 RSP: 002b:00007f6a015b2da8 EFLAGS: 00000293 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00000000006dac24 RCX: 0000000000449309 RDX: 0000000020000080 RSI: 0000000000000003 RDI: 0000000000000003 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000102000004 R11: 0000000000000293 R12: 00000000006dac20 R13: 6f6f6c2f7665642f R14: 0000000102000004 R15: 0000000000000006 Showing all locks held in the system: 2 locks held by khungtaskd/892: #0: 00000000d274b5d9 (rcu_read_lock){....}, at: check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline] #0: 00000000d274b5d9 (rcu_read_lock){....}, at: watchdog+0x1ff/0xf60 kernel/hung_task.c:249 #1: 000000004982302b (tasklist_lock){.+.+}, at: debug_show_all_locks+0xde/0x34a kernel/locking/lockdep.c:4470 2 locks held by getty/4413: #0: 000000007750581b (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 000000004920c874 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x321/0x1cc0 drivers/tty/n_tty.c:2131 2 locks held by getty/4414: #0: 00000000a09880fe (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000b285e29b (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x321/0x1cc0 drivers/tty/n_tty.c:2131 2 locks held by getty/4415: #0: 00000000d3288751 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 000000008e8a5bce (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x321/0x1cc0 drivers/tty/n_tty.c:2131 2 locks held by getty/4416: #0: 000000009fd17772 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000d58c4c19 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x321/0x1cc0 drivers/tty/n_tty.c:2131 2 locks held by getty/4417: #0: 00000000245b57ce (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 000000000580a845 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x321/0x1cc0 drivers/tty/n_tty.c:2131 2 locks held by getty/4418: #0: 00000000697c63cf (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 0000000084b80924 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x321/0x1cc0 drivers/tty/n_tty.c:2131 2 locks held by getty/4419: #0: 000000006bd1bffc (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 000000003e1ee73e (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x321/0x1cc0 drivers/tty/n_tty.c:2131 1 lock held by syz-executor074/4445: #0: 00000000784072e6 (&lo->lo_ctl_mutex/1){+.+.}, at: lo_ioctl+0x8d/0x2130 drivers/block/loop.c:1391 1 lock held by syz-executor074/4448: #0: 00000000784072e6 (&lo->lo_ctl_mutex/1){+.+.}, at: lo_ioctl+0x8d/0x2130 drivers/block/loop.c:1391 1 lock held by syz-executor074/4450: #0: 00000000784072e6 (&lo->lo_ctl_mutex/1){+.+.}, at: lo_ioctl+0x8d/0x2130 drivers/block/loop.c:1391 1 lock held by syz-executor074/4451: #0: 00000000784072e6 (&lo->lo_ctl_mutex/1){+.+.}, at: lo_ioctl+0x8d/0x2130 drivers/block/loop.c:1391 1 lock held by syz-executor074/4453: #0: 00000000784072e6 (&lo->lo_ctl_mutex/1){+.+.}, at: lo_ioctl+0x8d/0x2130 drivers/block/loop.c:1391 1 lock held by syz-executor074/4454: #0: 00000000784072e6 (&lo->lo_ctl_mutex/1){+.+.}, at: lo_ioctl+0x8d/0x2130 drivers/block/loop.c:1391 1 lock held by syz-executor074/4456: #0: 00000000784072e6 (&lo->lo_ctl_mutex/1){+.+.}, at: lo_ioctl+0x8d/0x2130 drivers/block/loop.c:1391 1 lock held by syz-executor074/4457: #0: 00000000784072e6 (&lo->lo_ctl_mutex/1){+.+.}, at: lo_ioctl+0x8d/0x2130 drivers/block/loop.c:1391 1 lock held by syz-executor074/5167: #0: 00000000784072e6 (&lo->lo_ctl_mutex/1){+.+.}, at: lo_ioctl+0x8d/0x2130 drivers/block/loop.c:1391 1 lock held by syz-executor074/5168: #0: 00000000784072e6 (&lo->lo_ctl_mutex/1){+.+.}, at: lo_ioctl+0x8d/0x2130 drivers/block/loop.c:1391 1 lock held by syz-executor074/5169: #0: 00000000784072e6 (&lo->lo_ctl_mutex/1){+.+.}, at: lo_ioctl+0x8d/0x2130 drivers/block/loop.c:1391 1 lock held by blkid/5172: #0: 00000000784072e6 (&lo->lo_ctl_mutex/1){+.+.}, at: lo_ioctl+0x8d/0x2130 drivers/block/loop.c:1391 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 892 Comm: khungtaskd Not tainted 4.17.0-rc2+ #23 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+0x1b9/0x294 lib/dump_stack.c:113 nmi_cpu_backtrace.cold.4+0x19/0xce lib/nmi_backtrace.c:103 nmi_trigger_cpumask_backtrace+0x151/0x192 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:138 [inline] check_hung_task kernel/hung_task.c:132 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:190 [inline] watchdog+0xc10/0xf60 kernel/hung_task.c:249 kthread+0x345/0x410 kernel/kthread.c:238 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:412 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 4440 Comm: sshd Not tainted 4.17.0-rc2+ #23 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__trace_hardirqs_on_caller kernel/locking/lockdep.c:2840 [inline] RIP: 0010:trace_hardirqs_on_caller+0x219/0x5c0 kernel/locking/lockdep.c:2883 RSP: 0018:ffff8801d901f918 EFLAGS: 00000046 RAX: dffffc0000000000 RBX: ffff8801b8fb2600 RCX: 1ffff100371f65cb RDX: ffff8801b8fb2de0 RSI: ffff8801b8fb2e38 RDI: ffff8801b8fb2de0 RBP: ffff8801d901f928 R08: ffff8801b8fb2e38 R09: 0000000000000006 R10: ffff8801b8fb2600 R11: 0000000000000000 R12: ffffffff81685ed2 R13: ffffffff88d18ae0 R14: 1ffffffff11a315e R15: 0000000000000200 FS: 00007f0fe33307c0(0000) GS:ffff8801daf00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000001b8d000 CR3: 00000001ba379000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: trace_hardirqs_on+0xd/0x10 kernel/locking/lockdep.c:2890 seqcount_lockdep_reader_access include/linux/seqlock.h:83 [inline] read_seqcount_begin include/linux/seqlock.h:164 [inline] current_kernel_time64+0x242/0x2f0 kernel/time/timekeeping.c:2149 current_kernel_time include/linux/timekeeping32.h:14 [inline] current_time+0x16/0xc0 fs/inode.c:2125 touch_atime+0x20f/0x310 fs/inode.c:1743 file_accessed include/linux/fs.h:2063 [inline] pipe_read+0x7c5/0x940 fs/pipe.c:343 call_read_iter include/linux/fs.h:1778 [inline] new_sync_read fs/read_write.c:406 [inline] __vfs_read+0x696/0xa50 fs/read_write.c:418 vfs_read+0x17f/0x3d0 fs/read_write.c:452 ksys_read+0xf9/0x250 fs/read_write.c:578 __do_sys_read fs/read_write.c:588 [inline] __se_sys_read fs/read_write.c:586 [inline] __x64_sys_read+0x73/0xb0 fs/read_write.c:586 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7f0fe16cb310 RSP: 002b:00007ffd3e4c77c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 000055d006cd4f00 RCX: 00007f0fe16cb310 RDX: 0000000000004000 RSI: 00007ffd3e4c77d0 RDI: 0000000000000009 RBP: 00007f0fe33306a0 R08: 00007ffd3e4cb8b0 R09: 0101010101010101 R10: 0000000000000008 R11: 0000000000000246 R12: 0000000000000000 R13: 000055d006cd3a90 R14: 000055d006cd3a70 R15: 0000000000000050 Code: 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 88 03 00 00 48 8d bb e0 07 00 00 4c 89 a3 e8 07 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa <48> c1 ea 03 0f b6 04 02 84 c0 74 08 3c 03 0f 8e d7 02 00 00 8b