RDX: 04000000000000eb RSI: 000000002000d180 RDI: 0000000000000006 RBP: 000000000076bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000008 R13: 00000000000008d2 R14: 00000000004cb36d R15: 000000000000005c INFO: task syz-executor.1:7512 blocked for more than 140 seconds. Not tainted 4.14.172-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.1 D25440 7512 1 0x00000004 Call Trace: schedule+0x8d/0x1b0 kernel/sched/core.c:3428 __rwsem_down_write_failed_common kernel/locking/rwsem-xadd.c:588 [inline] rwsem_down_write_failed+0x5c3/0xbb0 kernel/locking/rwsem-xadd.c:617 call_rwsem_down_write_failed+0x13/0x20 arch/x86/lib/rwsem.S:105 __down_write arch/x86/include/asm/rwsem.h:126 [inline] down_write+0x4f/0x90 kernel/locking/rwsem.c:56 inode_lock include/linux/fs.h:718 [inline] vfs_unlink+0xc0/0x480 fs/namei.c:4018 do_unlinkat+0x315/0x5d0 fs/namei.c:4092 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x45c1c7 RSP: 002b:00007ffd2feffa38 EFLAGS: 00000246 ORIG_RAX: 0000000000000057 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000045c1c7 RDX: 00007ffd2feffa50 RSI: 00007ffd2feffa50 RDI: 00007ffd2feffae0 RBP: 0000000000000b9a R08: 0000000000000000 R09: 0000000000000009 R10: 0000000000000003 R11: 0000000000000246 R12: 00007ffd2ff00b70 R13: 0000000001c64940 R14: 0000000000000000 R15: 00007ffd2ff00b70 Showing all locks held in the system: 1 lock held by khungtaskd/1057: #0: (tasklist_lock){.+.+}, at: [] debug_show_all_locks+0x7c/0x21a kernel/locking/lockdep.c:4544 2 locks held by getty/7466: #0: (&tty->ldisc_sem){++++}, at: [] tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:284 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e4/0x16f0 drivers/tty/n_tty.c:2156 2 locks held by getty/7467: #0: (&tty->ldisc_sem){++++}, at: [] tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:284 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e4/0x16f0 drivers/tty/n_tty.c:2156 2 locks held by getty/7468: #0: (&tty->ldisc_sem){++++}, at: [] tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:284 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e4/0x16f0 drivers/tty/n_tty.c:2156 2 locks held by getty/7469: #0: (&tty->ldisc_sem){++++}, at: [] tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:284 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e4/0x16f0 drivers/tty/n_tty.c:2156 2 locks held by getty/7470: #0: (&tty->ldisc_sem){++++}, at: [] tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:284 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e4/0x16f0 drivers/tty/n_tty.c:2156 2 locks held by getty/7471: #0: (&tty->ldisc_sem){++++}, at: [] tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:284 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e4/0x16f0 drivers/tty/n_tty.c:2156 2 locks held by getty/7472: #0: (&tty->ldisc_sem){++++}, at: [] tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:284 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e4/0x16f0 drivers/tty/n_tty.c:2156 3 locks held by syz-executor.1/7512: #0: (sb_writers#4){.+.+}, at: [] sb_start_write include/linux/fs.h:1548 [inline] #0: (sb_writers#4){.+.+}, at: [] mnt_want_write+0x3a/0xb0 fs/namespace.c:386 #1: (&type->i_mutex_dir_key#3/1){+.+.}, at: [] inode_lock_nested include/linux/fs.h:753 [inline] #1: (&type->i_mutex_dir_key#3/1){+.+.}, at: [] do_unlinkat+0x201/0x5d0 fs/namei.c:4078 #2: (&sb->s_type->i_mutex_key#9){++++}, at: [] inode_lock include/linux/fs.h:718 [inline] #2: (&sb->s_type->i_mutex_key#9){++++}, at: [] vfs_unlink+0xc0/0x480 fs/namei.c:4018 2 locks held by syz-executor.1/32643: #0: (sb_writers#4){.+.+}, at: [] file_start_write include/linux/fs.h:2707 [inline] #0: (sb_writers#4){.+.+}, at: [] vfs_write+0x3a6/0x4e0 fs/read_write.c:543 #1: (&sb->s_type->i_mutex_key#9){++++}, at: [] inode_trylock include/linux/fs.h:738 [inline] #1: (&sb->s_type->i_mutex_key#9){++++}, at: [] ext4_file_write_iter+0x1d5/0xdc0 fs/ext4/file.c:236 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1057 Comm: khungtaskd Not tainted 4.14.172-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x13e/0x194 lib/dump_stack.c:58 nmi_cpu_backtrace.cold+0x57/0x93 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x139/0x17e lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:140 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:195 [inline] watchdog+0x5e2/0xb80 kernel/hung_task.c:274 kthread+0x30d/0x420 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 skipped: idling at pc 0xffffffff86401cbe