syz-executor0(25385): getblk(): executed=9 bh_count=0 bh_state=0 syz-executor0(25384): getblk(): executed=9 bh_count=0 bh_state=0 kworker/u4:5(7341): getblk(): executed=9 bh_count=0 bh_state=0 syz-executor0(25385): getblk(): executed=9 bh_count=0 bh_state=0 syz-executor0(25384): getblk(): executed=9 bh_count=0 bh_state=0 INFO: task syz-executor0:25358 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 D16552 25358 5541 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] generic_file_write_iter+0xed/0x870 mm/filemap.c:3198 call_write_iter include/linux/fs.h:1844 [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: fd b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 cb b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f5235913c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457569 RDX: 0000000000000020 RSI: 0000000020000040 RDI: 0000000000000004 RBP: 000000000072bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f52359146d4 R13: 00000000004cb4d0 R14: 00000000004d8b50 R15: 00000000ffffffff INFO: task syz-executor0:25371 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 D17704 25371 5541 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 kworker/u4:5(7341): getblk(): executed=9 bh_count=0 bh_state=0 __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_open fs/open.c:1081 [inline] __se_sys_open fs/open.c:1076 [inline] __x64_sys_open+0x7e/0xc0 fs/open.c:1076 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457569 Code: fd b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 cb b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f52358f2c78 EFLAGS: 00000246 syz-executor0(25385): getblk(): executed=9 bh_count=0 bh_state=0 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457569 RDX: 0000000000000000 RSI: 0000000000141042 RDI: 00000000200001c0 RBP: 000000000072bfa0 R08: 0000000000000000 R09: 0000000000000000 syz-executor0(25384): getblk(): executed=9 bh_count=0 bh_state=0 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f52358f36d4 R13: 00000000004ef97f R14: 00000000004d3fd8 R15: 00000000ffffffff Showing all locks held in the system: 1 lock held by khungtaskd/981: #0: 000000000d682a32 (rcu_read_lock){....}, at: debug_show_all_locks+0xd0/0x424 kernel/locking/lockdep.c:4379 1 lock held by rsyslogd/5408: #0: 000000001e45a368 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1bb/0x200 fs/file.c:766 2 locks held by getty/5499: #0: 00000000153f190f (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000b1804c62 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/5500: #0: 0000000014c808d3 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000579edd65 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/5501: #0: 00000000af1daf99 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000335fdaa7 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/5502: #0: 00000000bb3e3b87 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000c19ae9c3 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/5503: #0: 00000000f574680d (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 000000004a61a5ef (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/5504: #0: 00000000c3add7d9 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000764dee22 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/5505: #0: 00000000dc9ffeb1 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 0000000052908df5 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 4 locks held by kworker/u4:5/7341: 3 locks held by syz-executor0/25358: #0: 00000000d072d68f (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1bb/0x200 fs/file.c:766 #1: 000000008480959c (sb_writers#15){.+.+}, at: file_start_write include/linux/fs.h:2805 [inline] #1: 000000008480959c (sb_writers#15){.+.+}, at: vfs_write+0x42a/0x560 fs/read_write.c:548 #2: 00000000b623cc3d (&sb->s_type->i_mutex_key#22){++++}, at: inode_lock include/linux/fs.h:764 [inline] #2: 00000000b623cc3d (&sb->s_type->i_mutex_key#22){++++}, at: generic_file_write_iter+0xed/0x870 mm/filemap.c:3198 2 locks held by syz-executor0/25371: #0: 000000008480959c (sb_writers#15){.+.+}, at: sb_start_write include/linux/fs.h:1602 [inline] #0: 000000008480959c (sb_writers#15){.+.+}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:359 #1: 000000006793ec1f (&sb->s_type->i_mutex_key#22){++++}, at: inode_lock include/linux/fs.h:764 [inline] #1: 000000006793ec1f (&sb->s_type->i_mutex_key#22){++++}, at: do_last fs/namei.c:3321 [inline] #1: 000000006793ec1f (&sb->s_type->i_mutex_key#22){++++}, at: path_openat+0x15c4/0x5150 fs/namei.c:3534 3 locks held by syz-executor0/25384: 3 locks held by syz-executor0/25385: ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 981 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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 7341 Comm: kworker/u4:5 Not tainted 4.19.0-rc8-next-20181019+ #98 INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.923 msecs Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: writeback wb_workfn (flush-7:0) RIP: 0010:get_current arch/x86/include/asm/current.h:15 [inline] RIP: 0010:debug_lockdep_rcu_enabled.part.3+0x18/0x60 kernel/rcu/update.c:249 Code: 00 00 00 eb dc 0f 0b b8 ff ff ff ff 5d c3 0f 1f 40 00 48 b8 00 00 00 00 00 fc ff df 55 48 89 e5 53 65 48 8b 1c 25 40 ee 01 00 <48> 8d bb 7c 08 00 00 48 89 fa 48 c1 ea 03 0f b6 14 02 48 89 f8 83 RSP: 0018:ffff880185e45978 EFLAGS: 00000202 RAX: dffffc0000000000 RBX: ffff8801c26460c0 RCX: ffffffff87bbbc2b RDX: 0000000000000004 RSI: ffffffff87bbbc3e RDI: ffffffff89703920 RBP: ffff880185e45980 R08: ffff8801c26460c0 R09: ffffed003b5c5b4f R10: ffffed003b5c5b4f R11: ffff8801dae2da7b R12: 0000000000000001 R13: ffff8801c4d4c300 R14: 000000156e000203 R15: ffff880185e45a60 FS: 0000000000000000(0000) GS:ffff8801dae00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffff600400 CR3: 00000001c7e66000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: debug_lockdep_rcu_enabled kernel/rcu/update.c:248 [inline] rcu_read_lock_held+0x77/0xc0 kernel/rcu/update.c:275 xa_entry include/linux/xarray.h:555 [inline] xas_descend+0x413/0x510 lib/xarray.c:198 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_start_all fs/fs-writeback.c:1882 [inline] wb_do_writeback fs/fs-writeback.c:1908 [inline] wb_workfn+0xedf/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