INFO: task syz-executor.1:6968 blocked for more than 143 seconds. Not tainted 5.8.0-rc6-next-20200724-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.1 D24304 6968 1 0x00000004 Call Trace: context_switch kernel/sched/core.c:3533 [inline] __schedule+0x908/0x21e0 kernel/sched/core.c:4289 schedule+0xd0/0x2a0 kernel/sched/core.c:4364 rwsem_down_write_slowpath+0x603/0xc60 kernel/locking/rwsem.c:1235 __down_write kernel/locking/rwsem.c:1389 [inline] down_write+0x137/0x150 kernel/locking/rwsem.c:1532 inode_lock include/linux/fs.h:771 [inline] vfs_unlink+0xcd/0x600 fs/namei.c:3822 do_unlinkat+0x3b8/0x660 fs/namei.c:3895 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:384 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45c117 Code: Bad RIP value. RSP: 002b:00007ffd0ef32f88 EFLAGS: 00000246 ORIG_RAX: 0000000000000057 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000045c117 RDX: 00007ffd0ef32fa0 RSI: 00007ffd0ef32fa0 RDI: 00007ffd0ef33030 RBP: 0000000000000b19 R08: 0000000000000000 R09: 000000000000000f R10: 0000000000000008 R11: 0000000000000246 R12: 00007ffd0ef340c0 R13: 0000000000e7e940 R14: 0000000000000000 R15: 00007ffd0ef340c0 Showing all locks held in the system: 1 lock held by khungtaskd/1162: #0: ffffffff89c52bc0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:5817 2 locks held by systemd-journal/3894: 1 lock held by in:imklog/6509: #0: ffff8880960bb630 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:930 2 locks held by agetty/6747: #0: ffff8880a6720098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:267 #1: ffffc90000f442e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x223/0x1a30 drivers/tty/n_tty.c:2156 3 locks held by syz-executor.1/6968: #0: ffff888098e5a450 (sb_writers#4){.+.+}-{0:0}, at: sb_start_write include/linux/fs.h:1644 [inline] #0: ffff888098e5a450 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x3a/0xb0 fs/namespace.c:368 #1: ffff888025cd0848 (&type->i_mutex_dir_key#3/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:806 [inline] #1: ffff888025cd0848 (&type->i_mutex_dir_key#3/1){+.+.}-{3:3}, at: do_unlinkat+0x27d/0x660 fs/namei.c:3881 #2: ffff888025e925c8 (&sb->s_type->i_mutex_key#10){++++}-{3:3}, at: inode_lock include/linux/fs.h:771 [inline] #2: ffff888025e925c8 (&sb->s_type->i_mutex_key#10){++++}-{3:3}, at: vfs_unlink+0xcd/0x600 fs/namei.c:3822 2 locks held by syz-executor.1/17196: #0: ffff888098e5a450 (sb_writers#4){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2785 [inline] #0: ffff888098e5a450 (sb_writers#4){.+.+}-{0:0}, at: vfs_write+0x568/0x6f0 fs/read_write.c:591 #1: ffff888025e925c8 (&sb->s_type->i_mutex_key#10){++++}-{3:3}, at: inode_lock include/linux/fs.h:771 [inline] #1: ffff888025e925c8 (&sb->s_type->i_mutex_key#10){++++}-{3:3}, at: ext4_buffered_write_iter+0xb3/0x4a0 fs/ext4/file.c:264 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1162 Comm: khungtaskd Not tainted 5.8.0-rc6-next-20200724-syzkaller #0 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+0x18f/0x20d lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x44/0xd7 lib/nmi_backtrace.c:105 nmi_trigger_cpumask_backtrace+0x1b3/0x223 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:147 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:253 [inline] watchdog+0xd89/0xf30 kernel/hung_task.c:339 kthread+0x3b5/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 3894 Comm: systemd-journal Not tainted 5.8.0-rc6-next-20200724-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:lock_is_held_type+0xcc/0xf0 kernel/locking/lockdep.c:5039 Code: 08 00 00 83 e8 01 66 85 c0 89 82 cc 08 00 00 75 27 4c 89 ff e8 b5 8c 6c f9 48 83 c4 08 44 89 e0 5b 5d 41 5c 41 5d 41 5e 41 5f 45 31 e4 eb c4 41 bc 01 00 00 00 eb e1 0f 0b c7 82 cc 08 00 00 RSP: 0018:ffffc90001647f00 EFLAGS: 00000092 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 1ffffffff1306328 RDX: dffffc0000000000 RSI: 00000000ffffffff RDI: 0000000000000086 RBP: ffffc90001647f58 R08: 0000000000000000 R09: ffffffff8ab8eecf R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000001 R13: ffffffff87ec7067 R14: 0000000000000000 R15: 0000000000000000 FS: 00007f898ecaa8c0(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f898c24d000 CR3: 0000000093005000 CR4: 00000000001506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_is_held include/linux/lockdep.h:265 [inline] rcu_read_lock_sched_held+0x3a/0xb0 kernel/rcu/update.c:123 trace_irq_disable include/trace/events/preemptirq.h:36 [inline] trace_hardirqs_off_finish kernel/trace/trace_preemptirq.c:67 [inline] trace_hardirqs_off_finish+0x26b/0x2d0 kernel/trace/trace_preemptirq.c:61 enter_from_user_mode arch/x86/entry/common.c:102 [inline] do_syscall_64+0x17/0xe0 arch/x86/entry/common.c:374 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7f898e23a210 Code: Bad RIP value. RSP: 002b:00007ffdec7e9f38 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 00007ffdec7ec9b0 RCX: 00007f898e23a210 RDX: 0000000000002000 RSI: 00007ffdec7ea7b0 RDI: 0000000000000009 RBP: 0000000000000000 R08: 0000000000000008 R09: 00007ffdec7f80f0 R10: 0000000000053766 R11: 0000000000000246 R12: 00007ffdec7ea7b0 R13: 00007ffdec7ec908 R14: 000055bfbd944958 R15: 0005ab4de87d8dfd