INFO: task syz-executor5:19703 blocked for more than 140 seconds. Not tainted 4.19.0-rc8+ #291 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor5 D19416 19703 5503 0x00000004 Call Trace: context_switch kernel/sched/core.c:2825 [inline] __schedule+0x86c/0x1ed0 kernel/sched/core.c:3473 schedule+0xfe/0x460 kernel/sched/core.c:3517 io_schedule+0x1c/0x70 kernel/sched/core.c:5140 wait_on_page_bit_common+0x5b4/0x890 mm/filemap.c:1100 __lock_page+0x112/0x170 mm/filemap.c:1273 lock_page include/linux/pagemap.h:483 [inline] pagecache_get_page+0x89f/0xf00 mm/filemap.c:1554 grab_cache_page_write_begin+0x75/0xa0 mm/filemap.c:3089 block_write_begin+0xae/0x370 fs/buffer.c:2071 blkdev_write_begin+0x3c/0x50 fs/block_dev.c:585 generic_perform_write+0x3aa/0x6a0 mm/filemap.c:3139 __generic_file_write_iter+0x26e/0x630 mm/filemap.c:3264 blkdev_write_iter+0x23d/0x450 fs/block_dev.c:1916 call_write_iter include/linux/fs.h:1808 [inline] new_sync_write fs/read_write.c:474 [inline] __vfs_write+0x6b8/0x9f0 fs/read_write.c:487 vfs_write+0x1fc/0x560 fs/read_write.c:549 ksys_write+0x101/0x260 fs/read_write.c:598 __do_sys_write fs/read_write.c:610 [inline] __se_sys_write fs/read_write.c:607 [inline] __x64_sys_write+0x73/0xb0 fs/read_write.c:607 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457569 Code: 83 c4 18 c3 e8 d8 64 00 00 48 8b 04 24 48 8b 4c 24 08 48 89 01 e8 d7 2d fc ff e8 22 7a fc ff b8 02 00 00 00 48 8d 0d 2a 60 09 <01> 87 01 8b 05 22 60 09 01 83 f8 01 0f 85 8a 00 00 00 b8 01 00 00 RSP: 002b:00007f756f45ac78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457569 RDX: 0000000000000002 RSI: 0000000020000540 RDI: 0000000000000005 RBP: 000000000072bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f756f45b6d4 R13: 00000000004cb700 R14: 00000000004d8dc0 R15: 00000000ffffffff INFO: task syz-executor5:19715 blocked for more than 140 seconds. Not tainted 4.19.0-rc8+ #291 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor5 D22376 19715 5503 0x00000004 Call Trace: context_switch kernel/sched/core.c:2825 [inline] __schedule+0x86c/0x1ed0 kernel/sched/core.c:3473 schedule+0xfe/0x460 kernel/sched/core.c:3517 io_schedule+0x1c/0x70 kernel/sched/core.c:5140 bit_wait_io+0xf/0x90 kernel/sched/wait_bit.c:207 __wait_on_bit+0xb3/0x130 kernel/sched/wait_bit.c:48 out_of_line_wait_on_bit+0x213/0x3c0 kernel/sched/wait_bit.c:63 wait_on_bit_io include/linux/wait_bit.h:101 [inline] __wait_on_buffer fs/buffer.c:118 [inline] wait_on_buffer include/linux/buffer_head.h:354 [inline] __block_write_begin_int+0xa96/0x1d90 fs/buffer.c:2004 __block_write_begin fs/buffer.c:2016 [inline] block_write_begin+0xda/0x370 fs/buffer.c:2075 blkdev_write_begin+0x3c/0x50 fs/block_dev.c:585 generic_perform_write+0x3aa/0x6a0 mm/filemap.c:3139 __generic_file_write_iter+0x26e/0x630 mm/filemap.c:3264 blkdev_write_iter+0x23d/0x450 fs/block_dev.c:1916 call_write_iter include/linux/fs.h:1808 [inline] new_sync_write fs/read_write.c:474 [inline] __vfs_write+0x6b8/0x9f0 fs/read_write.c:487 vfs_write+0x1fc/0x560 fs/read_write.c:549 ksys_write+0x101/0x260 fs/read_write.c:598 __do_sys_write fs/read_write.c:610 [inline] __se_sys_write fs/read_write.c:607 [inline] __x64_sys_write+0x73/0xb0 fs/read_write.c:607 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457569 Code: 83 c4 18 c3 e8 d8 64 00 00 48 8b 04 24 48 8b 4c 24 08 48 89 01 e8 d7 2d fc ff e8 22 7a fc ff b8 02 00 00 00 48 8d 0d 2a 60 09 <01> 87 01 8b 05 22 60 09 01 83 f8 01 0f 85 8a 00 00 00 b8 01 00 00 RSP: 002b:00007f756f439c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457569 RDX: 0000000000000002 RSI: 0000000020000100 RDI: 0000000000000005 RBP: 000000000072bfa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f756f43a6d4 R13: 00000000004cb700 R14: 00000000004d8dc0 R15: 00000000ffffffff INFO: task syz-executor5:19727 blocked for more than 140 seconds. Not tainted 4.19.0-rc8+ #291 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor5 D19336 19727 5503 0x00000004 Call Trace: context_switch kernel/sched/core.c:2825 [inline] __schedule+0x86c/0x1ed0 kernel/sched/core.c:3473 schedule+0xfe/0x460 kernel/sched/core.c:3517 io_schedule+0x1c/0x70 kernel/sched/core.c:5140 wait_on_page_bit_common+0x5b4/0x890 mm/filemap.c:1100 __lock_page+0x112/0x170 mm/filemap.c:1273 lock_page include/linux/pagemap.h:483 [inline] pagecache_get_page+0x89f/0xf00 mm/filemap.c:1554 grab_cache_page_write_begin+0x75/0xa0 mm/filemap.c:3089 block_write_begin+0xae/0x370 fs/buffer.c:2071 blkdev_write_begin+0x3c/0x50 fs/block_dev.c:585 generic_perform_write+0x3aa/0x6a0 mm/filemap.c:3139 __generic_file_write_iter+0x26e/0x630 mm/filemap.c:3264 blkdev_write_iter+0x23d/0x450 fs/block_dev.c:1916 call_write_iter include/linux/fs.h:1808 [inline] new_sync_write fs/read_write.c:474 [inline] __vfs_write+0x6b8/0x9f0 fs/read_write.c:487 vfs_write+0x1fc/0x560 fs/read_write.c:549 ksys_write+0x101/0x260 fs/read_write.c:598 __do_sys_write fs/read_write.c:610 [inline] __se_sys_write fs/read_write.c:607 [inline] __x64_sys_write+0x73/0xb0 fs/read_write.c:607 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457569 Code: 83 c4 18 c3 e8 d8 64 00 00 48 8b 04 24 48 8b 4c 24 08 48 89 01 e8 d7 2d fc ff e8 22 7a fc ff b8 02 00 00 00 48 8d 0d 2a 60 09 <01> 87 01 8b 05 22 60 09 01 83 f8 01 0f 85 8a 00 00 00 b8 01 00 00 RSP: 002b:00007f756f418c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457569 RDX: 0000000000000002 RSI: 0000000020000100 RDI: 0000000000000003 RBP: 000000000072c040 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f756f4196d4 R13: 00000000004cb700 R14: 00000000004d8dc0 R15: 00000000ffffffff INFO: task syz-executor5:19777 blocked for more than 140 seconds. Not tainted 4.19.0-rc8+ #291 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor5 D24512 19777 5503 0x00000004 Call Trace: context_switch kernel/sched/core.c:2825 [inline] __schedule+0x86c/0x1ed0 kernel/sched/core.c:3473 schedule+0xfe/0x460 kernel/sched/core.c:3517 io_schedule+0x1c/0x70 kernel/sched/core.c:5140 wait_on_page_bit_common+0x5b4/0x890 mm/filemap.c:1100 __lock_page+0x112/0x170 mm/filemap.c:1273 lock_page include/linux/pagemap.h:483 [inline] pagecache_get_page+0x89f/0xf00 mm/filemap.c:1554 grab_cache_page_write_begin+0x75/0xa0 mm/filemap.c:3089 block_write_begin+0xae/0x370 fs/buffer.c:2071 blkdev_write_begin+0x3c/0x50 fs/block_dev.c:585 generic_perform_write+0x3aa/0x6a0 mm/filemap.c:3139 __generic_file_write_iter+0x26e/0x630 mm/filemap.c:3264 blkdev_write_iter+0x23d/0x450 fs/block_dev.c:1916 call_write_iter include/linux/fs.h:1808 [inline] new_sync_write fs/read_write.c:474 [inline] __vfs_write+0x6b8/0x9f0 fs/read_write.c:487 vfs_write+0x1fc/0x560 fs/read_write.c:549 ksys_write+0x101/0x260 fs/read_write.c:598 __do_sys_write fs/read_write.c:610 [inline] __se_sys_write fs/read_write.c:607 [inline] __x64_sys_write+0x73/0xb0 fs/read_write.c:607 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457569 Code: Bad RIP value. RSP: 002b:00007f756f3f7c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457569 RDX: 0000000000000002 RSI: 0000000020000540 RDI: 0000000000000003 RBP: 000000000072c0e0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f756f3f86d4 R13: 00000000004cb700 R14: 00000000004d8dc0 R15: 00000000ffffffff Showing all locks held in the system: 1 lock held by khungtaskd/982: #0: 000000006d1d1811 (rcu_read_lock){....}, at: debug_show_all_locks+0xd0/0x424 kernel/locking/lockdep.c:4435 1 lock held by rsyslogd/5229: #0: 000000008aa16a96 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1bb/0x200 fs/file.c:766 2 locks held by getty/5319: #0: 000000006c0ba8b5 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 000000003c86aa17 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/5320: #0: 0000000057bb7933 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000070f5340 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/5321: #0: 00000000578f77e0 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 0000000091272a91 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/5322: #0: 000000000eb5a258 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000a34cc00e (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/5323: #0: 00000000edb91c3a (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000ca521f16 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/5324: #0: 000000001774e32c (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000eea9fbca (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/5325: #0: 00000000499274e8 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000af38afd4 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 982 Comm: khungtaskd Not tainted 4.19.0-rc8+ #291 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+0x1c4/0x2b4 lib/dump_stack.c:113 nmi_cpu_backtrace.cold.3+0x63/0xa2 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1b3/0x1ed 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:144 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:204 [inline] watchdog+0xb3e/0x1050 kernel/hung_task.c:265 kthread+0x35a/0x420 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:413 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 skipped: idling at native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:57