kworker/u4:0(7): getblk(): executed=9 bh_count=0 bh_state=0 kworker/u4:0(7): getblk(): executed=9 bh_count=0 bh_state=0 kworker/u4:0(7): getblk(): executed=9 bh_count=0 bh_state=0 kworker/u4:0(7): getblk(): executed=9 bh_count=0 bh_state=0 kworker/u4:0(7): getblk(): executed=9 bh_count=0 bh_state=0 INFO: task syz-executor3:21587 blocked for more than 140 seconds. Not tainted 4.20.0-next-20190102 #3 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor3 D25768 21587 13189 0x00000004 Call Trace: context_switch kernel/sched/core.c:2831 [inline] __schedule+0x897/0x1e60 kernel/sched/core.c:3472 schedule+0xfe/0x350 kernel/sched/core.c:3516 wb_wait_for_completion+0x1e0/0x2d0 fs/fs-writeback.c:221 sync_inodes_sb+0x335/0x490 fs/fs-writeback.c:2417 sync_inodes_one_sb+0x57/0x70 fs/sync.c:74 iterate_supers+0x149/0x290 fs/super.c:723 ksys_sync+0xdf/0x1d0 fs/sync.c:113 __ia32_sys_sync+0xe/0x20 fs/sync.c:124 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457ec9 Code: Bad RIP value. RSP: 002b:00007fe25450ac78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 000000000073bf08 RCX: 0000000000457ec9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 000000000073bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fe25450b6d4 R13: 00000000004c4101 R14: 00000000004daff0 R15: 00000000ffffffff INFO: task syz-executor3:21597 blocked for more than 140 seconds. Not tainted 4.20.0-next-20190102 #3 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor3 D22136 21597 13189 0x00000004 Call Trace: context_switch kernel/sched/core.c:2831 [inline] __schedule+0x897/0x1e60 kernel/sched/core.c:3472 schedule+0xfe/0x350 kernel/sched/core.c:3516 wb_wait_for_completion+0x1e0/0x2d0 fs/fs-writeback.c:221 sync_inodes_sb+0x335/0x490 fs/fs-writeback.c:2417 sync_inodes_one_sb+0x57/0x70 fs/sync.c:74 iterate_supers+0x149/0x290 fs/super.c:723 ksys_sync+0xdf/0x1d0 fs/sync.c:113 __ia32_sys_sync+0xe/0x20 fs/sync.c:124 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457ec9 Code: Bad RIP value. RSP: 002b:00007fe2544e9c78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 000000000073bfa8 RCX: 0000000000457ec9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 000000000073bfa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fe2544ea6d4 R13: 00000000004c4101 R14: 00000000004daff0 R15: 00000000ffffffff Showing all locks held in the system: 5 locks held by kworker/u4:0/7: 1 lock held by khungtaskd/1041: #0: 00000000e09accd0 (rcu_read_lock){....}, at: debug_show_all_locks+0xc6/0x41d kernel/locking/lockdep.c:4389 1 lock held by rsyslogd/7867: #0: 0000000016aa6b77 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1b3/0x1f0 fs/file.c:795 2 locks held by getty/7958: #0: 000000008ed64caf (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000e5f34e70 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x30a/0x1eb0 drivers/tty/n_tty.c:2154 2 locks held by getty/7959: #0: 00000000da432e87 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000430b8981 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x30a/0x1eb0 drivers/tty/n_tty.c:2154 2 locks held by getty/7960: #0: 00000000feb60ef3 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000c79434c6 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x30a/0x1eb0 drivers/tty/n_tty.c:2154 2 locks held by getty/7961: #0: 0000000096a99b89 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 0000000088ebd3e6 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x30a/0x1eb0 drivers/tty/n_tty.c:2154 2 locks held by getty/7962: #0: 00000000b0d21f17 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 0000000058981a42 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x30a/0x1eb0 drivers/tty/n_tty.c:2154 2 locks held by getty/7963: #0: 0000000066ecf36c (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000251613b0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x30a/0x1eb0 drivers/tty/n_tty.c:2154 2 locks held by getty/7964: #0: 000000005751f846 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000de95f6ff (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x30a/0x1eb0 drivers/tty/n_tty.c:2154 1 lock held by syz-executor3/21587: #0: 00000000066bd4a1 (&type->s_umount_key#50){++++}, at: iterate_supers+0xe2/0x290 fs/super.c:721 1 lock held by syz-executor3/21597: #0: 00000000066bd4a1 (&type->s_umount_key#50){++++}, at: iterate_supers+0xe2/0x290 fs/super.c:721 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1041 Comm: khungtaskd Not tainted 4.20.0-next-20190102 #3 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+0x1db/0x2d0 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+0xbbb/0x1170 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 0 to CPUs 1: NMI backtrace for cpu 1 INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.860 msecs CPU: 1 PID: 7 Comm: kworker/u4:0 Not tainted 4.20.0-next-20190102 #3 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: writeback wb_workfn (flush-7:0) RIP: 0010:__sanitizer_cov_trace_const_cmp4+0x1/0x20 kernel/kcov.c:188 Code: fe ff ff 5d c3 0f 1f 40 00 55 0f b7 d6 0f b7 f7 bf 03 00 00 00 48 89 e5 48 8b 4d 08 e8 d8 fe ff ff 5d c3 66 0f 1f 44 00 00 55 <89> f2 89 fe bf 05 00 00 00 48 89 e5 48 8b 4d 08 e8 ba fe ff ff 5d RSP: 0000:ffff8880a9466920 EFLAGS: 00000246 RAX: ffff8880a94581c0 RBX: 0000000000000001 RCX: ffffffff81a03ab9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffff8880a9466af0 R08: ffff8880a94581c0 R09: 0000000000000005 R10: 0000000000000000 R11: ffff8880ae72dc7b R12: ffffea00023b5e80 R13: dffffc0000000000 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffff600400 CR3: 00000000a50ce000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: find_get_page_flags include/linux/pagemap.h:279 [inline] __find_get_block_slow fs/buffer.c:205 [inline] __find_get_block fs/buffer.c:1325 [inline] __find_get_block+0x615/0xf20 fs/buffer.c:1319 __getblk_slow fs/buffer.c:1058 [inline] __getblk_gfp+0x3c5/0x1130 fs/buffer.c:1351 __bread_gfp+0x2f/0x300 fs/buffer.c:1385 sb_bread include/linux/buffer_head.h:307 [inline] fat_clusters_flush+0x127/0x3c0 fs/fat/misc.c:70 fat_write_inode fs/fat/inode.c:905 [inline] fat_write_inode+0x111/0x190 fs/fat/inode.c:897 write_inode fs/fs-writeback.c:1176 [inline] __writeback_single_inode+0xef1/0x1620 fs/fs-writeback.c:1375 writeback_sb_inodes+0x762/0x1260 fs/fs-writeback.c:1580 __writeback_inodes_wb+0x16d/0x3d0 fs/fs-writeback.c:1649 wb_writeback+0xa2d/0xf70 fs/fs-writeback.c:1758 wb_check_old_data_flush fs/fs-writeback.c:1860 [inline] wb_do_writeback fs/fs-writeback.c:1913 [inline] wb_workfn+0xf7f/0x16f0 fs/fs-writeback.c:1942 process_one_work+0xd0c/0x1ce0 kernel/workqueue.c:2153 worker_thread+0x143/0x14a0 kernel/workqueue.c:2296 kthread+0x357/0x430 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352