syz-executor0(20008): getblk(): executed=9 bh_count=0 bh_state=0 kworker/u4:4(30359): getblk(): executed=9 bh_count=0 bh_state=0 syz-executor0(20008): getblk(): executed=9 bh_count=0 bh_state=0 kworker/u4:4(30359): getblk(): executed=9 bh_count=0 bh_state=0 syz-executor0(20008): getblk(): executed=9 bh_count=0 bh_state=0 INFO: task syz-executor0:20014 blocked for more than 140 seconds. Not tainted 4.19.0-rc8-next-20181019+ #98 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor0 D23800 20014 5588 0x00000004 Call Trace: context_switch kernel/sched/core.c:2831 [inline] __schedule+0x8cf/0x21d0 kernel/sched/core.c:3480 schedule+0xfe/0x460 kernel/sched/core.c:3524 __rwsem_down_write_failed_common+0xc9a/0x15e0 kernel/locking/rwsem-xadd.c:577 rwsem_down_write_failed+0xe/0x10 kernel/locking/rwsem-xadd.c:606 call_rwsem_down_write_failed+0x17/0x30 arch/x86/lib/rwsem.S:117 __down_write arch/x86/include/asm/rwsem.h:142 [inline] down_write+0xa5/0x130 kernel/locking/rwsem.c:72 inode_lock include/linux/fs.h:764 [inline] do_last fs/namei.c:3321 [inline] path_openat+0x15c4/0x5150 fs/namei.c:3534 do_filp_open+0x255/0x380 fs/namei.c:3564 do_sys_open+0x568/0x700 fs/open.c:1063 __do_sys_openat fs/open.c:1090 [inline] __se_sys_openat fs/open.c:1084 [inline] __x64_sys_openat+0x9d/0x100 fs/open.c:1084 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:00007fcf75fe3c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 0000000000457569 RDX: 0000000000002761 RSI: 0000000020001b40 RDI: ffffffffffffffff RBP: 000000000072bfa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fcf75fe46d4 R13: 00000000004c2b12 R14: 00000000004d4140 R15: 00000000ffffffff Showing all locks held in the system: 1 lock held by khungtaskd/982: #0: 000000002eae59f3 (rcu_read_lock){....}, at: debug_show_all_locks+0xd0/0x424 kernel/locking/lockdep.c:4379 1 lock held by rsyslogd/5457: #0: 00000000d76f35b2 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1bb/0x200 fs/file.c:766 2 locks held by getty/5546: #0: 0000000087805cbb (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 0000000098d3d826 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/5547: #0: 00000000ae4f719d (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 000000005f39f7f5 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/5548: #0: 00000000e04f13d5 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 000000007e9fc90d (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/5549: #0: 000000001dfcbca9 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 000000001eb4a98a (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/5550: #0: 00000000574f46ef (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000dee0a6fa (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/5551: #0: 00000000c50792e3 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 000000005c6b3f19 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/5552: #0: 00000000ed7e39ce (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000c17db5e9 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 1 lock held by syz-executor0/5588: #0: 0000000098ad7050 (&sb->s_type->i_mutex_key#25){++++}, at: inode_lock_shared include/linux/fs.h:779 [inline] #0: 0000000098ad7050 (&sb->s_type->i_mutex_key#25){++++}, at: lookup_slow+0x49/0x80 fs/namei.c:1687 4 locks held by kworker/u4:4/30359: 3 locks held by syz-executor0/20008: 2 locks held by syz-executor0/20014: #0: 00000000b4a04a13 (sb_writers#17){.+.+}, at: sb_start_write include/linux/fs.h:1602 [inline] #0: 00000000b4a04a13 (sb_writers#17){.+.+}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:359 #1: 0000000098ad7050 (&sb->s_type->i_mutex_key#25){++++}, at: inode_lock include/linux/fs.h:764 [inline] #1: 0000000098ad7050 (&sb->s_type->i_mutex_key#25){++++}, at: do_last fs/namei.c:3321 [inline] #1: 0000000098ad7050 (&sb->s_type->i_mutex_key#25){++++}, at: path_openat+0x15c4/0x5150 fs/namei.c:3534 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 982 Comm: khungtaskd Not tainted 4.19.0-rc8-next-20181019+ #98 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+0x244/0x39d lib/dump_stack.c:113 nmi_cpu_backtrace.cold.2+0x5c/0xa1 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1e8/0x22a 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+0xb39/0x1050 kernel/hung_task.c:265 kthread+0x35a/0x440 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 Sending NMI from CPU 0 to CPUs 1: INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 2.565 msecs NMI backtrace for cpu 1 CPU: 1 PID: 30359 Comm: kworker/u4:4 Not tainted 4.19.0-rc8-next-20181019+ #98 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: writeback wb_workfn (flush-7:0) RIP: 0010:__read_once_size include/linux/compiler.h:179 [inline] RIP: 0010:xa_entry include/linux/xarray.h:555 [inline] RIP: 0010:xas_descend+0x118/0x510 lib/xarray.c:198 Code: 00 0f 85 88 03 00 00 48 8b 03 48 89 85 18 ff ff ff 44 89 e0 4d 8d 74 c5 28 48 b8 00 00 00 00 00 fc ff df 4c 89 f2 48 c1 ea 03 <80> 3c 02 00 0f 85 4e 03 00 00 49 8d 47 80 4d 8b 36 48 ba 00 00 00 RSP: 0018:ffff8801858ad9a0 EFLAGS: 00000a02 RAX: dffffc0000000000 RBX: ffff8801858adb90 RCX: 0000000000000006 RDX: 1ffff10029117c5e RSI: ffffffff87bbb8bd RDI: ffff8801858adb98 RBP: ffff8801858ada88 R08: ffff880186638380 R09: ffffed003b5e5b4f R10: ffffed003b5e5b4f R11: ffff8801daf2da7b R12: 0000000000000001 R13: ffff8801488be2c0 R14: ffff8801488be2f0 R15: ffff8801858ada60 FS: 0000000000000000(0000) GS:ffff8801daf00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000000045753f CR3: 0000000184087000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: xas_load+0x145/0x1e0 lib/xarray.c:234 find_get_entry+0x3ca/0x1120 mm/filemap.c:1415 pagecache_get_page+0x12f/0xf00 mm/filemap.c:1518 find_get_page_flags include/linux/pagemap.h:278 [inline] __find_get_block_slow fs/buffer.c:205 [inline] __find_get_block+0x635/0xf10 fs/buffer.c:1325 __getblk_slow fs/buffer.c:1058 [inline] __getblk_gfp+0x3d3/0x1030 fs/buffer.c:1351 __bread_gfp+0x2d/0x310 fs/buffer.c:1385 sb_bread include/linux/buffer_head.h:307 [inline] __fat_write_inode+0x347/0xb60 fs/fat/inode.c:860 fat_write_inode+0x97/0x180 fs/fat/inode.c:909 write_inode fs/fs-writeback.c:1176 [inline] __writeback_single_inode+0xf4a/0x1650 fs/fs-writeback.c:1375 writeback_sb_inodes+0x71f/0x1210 fs/fs-writeback.c:1580 __writeback_inodes_wb+0x1b9/0x340 fs/fs-writeback.c:1649 wb_writeback+0xa64/0xfb0 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+0xffe/0x1780 fs/fs-writeback.c:1942 process_one_work+0xc8b/0x1c40 kernel/workqueue.c:2153 worker_thread+0x17f/0x1390 kernel/workqueue.c:2296 kthread+0x35a/0x440 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352