INFO: task syz-executor2:15424 blocked for more than 140 seconds. Not tainted 5.0.0-rc1+ #23 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor2 D20328 15424 1 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 __rwsem_down_write_failed_common+0xa4d/0x1620 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:757 [inline] vfs_unlink+0xd1/0x500 fs/namei.c:3990 do_unlinkat+0x52a/0x9e0 fs/namei.c:4062 __do_sys_unlink fs/namei.c:4109 [inline] __se_sys_unlink fs/namei.c:4107 [inline] __x64_sys_unlink+0x42/0x50 fs/namei.c:4107 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457c17 Code: 67 35 20 01 48 89 4c 24 10 e8 15 b2 fc ff 48 8b 44 24 20 48 8d 50 01 48 8b 44 24 28 0f b6 4c 24 1f 48 83 fa 40 7d 1b 84 c9 74 <0b> 0f b6 98 c0 00 00 00 84 db 75 0c 48 8b 1d 8e 28 1e 01 48 85 db RSP: 002b:0000000000a4eca8 EFLAGS: 00000246 ORIG_RAX: 0000000000000057 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000457c17 RDX: 0000000000a4ecc0 RSI: 0000000000a4ecc0 RDI: 0000000000a4ed50 RBP: 00000000000008a6 R08: 0000000000000000 R09: 000000000000000b R10: 0000000000000005 R11: 0000000000000246 R12: 0000000000a4fde0 R13: 0000000000e35940 R14: 0000000000000000 R15: 0000000000000002 Showing all locks held in the system: 1 lock held by khungtaskd/1038: #0: 000000005f53174c (rcu_read_lock){....}, at: debug_show_all_locks+0xc6/0x41d kernel/locking/lockdep.c:4389 1 lock held by rsyslogd/7829: #0: 00000000adf2e95d (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1b3/0x1f0 fs/file.c:795 2 locks held by getty/7919: #0: 00000000fd1fb218 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000246e1411 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x30a/0x1eb0 drivers/tty/n_tty.c:2154 2 locks held by getty/7920: #0: 000000009f91adba (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000d1001c4b (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x30a/0x1eb0 drivers/tty/n_tty.c:2154 2 locks held by getty/7921: #0: 000000000240c927 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000003afc56eb (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x30a/0x1eb0 drivers/tty/n_tty.c:2154 2 locks held by getty/7922: #0: 000000009e452bb0 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000006167ea5d (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x30a/0x1eb0 drivers/tty/n_tty.c:2154 2 locks held by getty/7923: #0: 000000007f4653db (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000002fdd2a3d (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x30a/0x1eb0 drivers/tty/n_tty.c:2154 2 locks held by getty/7924: #0: 000000000ed004aa (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 0000000073f3e572 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x30a/0x1eb0 drivers/tty/n_tty.c:2154 2 locks held by getty/7925: #0: 00000000ca8af5d4 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000006eb873ff (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x30a/0x1eb0 drivers/tty/n_tty.c:2154 3 locks held by syz-executor2/15424: #0: 00000000ad877061 (sb_writers#5){.+.+}, at: sb_start_write include/linux/fs.h:1602 [inline] #0: 00000000ad877061 (sb_writers#5){.+.+}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:357 #1: 00000000594f2824 (&type->i_mutex_dir_key#4/1){+.+.}, at: inode_lock_nested include/linux/fs.h:792 [inline] #1: 00000000594f2824 (&type->i_mutex_dir_key#4/1){+.+.}, at: do_unlinkat+0x394/0x9e0 fs/namei.c:4048 #2: 0000000034d17044 (&sb->s_type->i_mutex_key#12){+.+.}, at: inode_lock include/linux/fs.h:757 [inline] #2: 0000000034d17044 (&sb->s_type->i_mutex_key#12){+.+.}, at: vfs_unlink+0xd1/0x500 fs/namei.c:3990 1 lock held by syz-executor0/25510: #0: 0000000050f6c678 (&sig->cred_guard_mutex){+.+.}, at: prepare_bprm_creds fs/exec.c:1407 [inline] #0: 0000000050f6c678 (&sig->cred_guard_mutex){+.+.}, at: __do_execve_file.isra.0+0x45d/0x2700 fs/exec.c:1750 1 lock held by syz-executor0/25562: #0: 000000009e5f00e9 (&sig->cred_guard_mutex){+.+.}, at: prepare_bprm_creds fs/exec.c:1407 [inline] #0: 000000009e5f00e9 (&sig->cred_guard_mutex){+.+.}, at: __do_execve_file.isra.0+0x45d/0x2700 fs/exec.c:1750 1 lock held by syz-executor0/25767: #0: 000000008a5af9b1 (&sig->cred_guard_mutex){+.+.}, at: prepare_bprm_creds fs/exec.c:1407 [inline] #0: 000000008a5af9b1 (&sig->cred_guard_mutex){+.+.}, at: __do_execve_file.isra.0+0x45d/0x2700 fs/exec.c:1750 1 lock held by syz-executor0/26124: #0: 000000008ca44ffd (&sig->cred_guard_mutex){+.+.}, at: prepare_bprm_creds fs/exec.c:1407 [inline] #0: 000000008ca44ffd (&sig->cred_guard_mutex){+.+.}, at: __do_execve_file.isra.0+0x45d/0x2700 fs/exec.c:1750 1 lock held by syz-executor0/26146: #0: 00000000bcaf44f6 (&sig->cred_guard_mutex){+.+.}, at: prepare_bprm_creds fs/exec.c:1407 [inline] #0: 00000000bcaf44f6 (&sig->cred_guard_mutex){+.+.}, at: __do_execve_file.isra.0+0x45d/0x2700 fs/exec.c:1750 1 lock held by syz-executor2/26223: #0: 00000000871569b8 (&sig->cred_guard_mutex){+.+.}, at: prepare_bprm_creds fs/exec.c:1407 [inline] #0: 00000000871569b8 (&sig->cred_guard_mutex){+.+.}, at: __do_execve_file.isra.0+0x45d/0x2700 fs/exec.c:1750 1 lock held by syz-executor2/26249: #0: 0000000056f4444f (&sig->cred_guard_mutex){+.+.}, at: prepare_bprm_creds fs/exec.c:1407 [inline] #0: 0000000056f4444f (&sig->cred_guard_mutex){+.+.}, at: __do_execve_file.isra.0+0x45d/0x2700 fs/exec.c:1750 3 locks held by syz-executor2/2939: #0: 00000000b8400d49 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1b3/0x1f0 fs/file.c:795 #1: 00000000ad877061 (sb_writers#5){.+.+}, at: file_start_write include/linux/fs.h:2815 [inline] #1: 00000000ad877061 (sb_writers#5){.+.+}, at: vfs_write+0x429/0x580 fs/read_write.c:548 #2: 0000000034d17044 (&sb->s_type->i_mutex_key#12){+.+.}, at: inode_lock include/linux/fs.h:757 [inline] #2: 0000000034d17044 (&sb->s_type->i_mutex_key#12){+.+.}, at: generic_file_write_iter+0xe5/0x6a0 mm/filemap.c:3358 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1038 Comm: khungtaskd Not tainted 5.0.0-rc1+ #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+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 skipped: idling at native_safe_halt+0x2/0x10 arch/x86/include/asm/irqflags.h:57