9pnet: p9_errstr2errno: server reported unknown error f <>>“90z7dW 9pnet: p9_errstr2errno: server reported unknown error f <>>“90z7dW INFO: task syz-executor4:1002 blocked for more than 140 seconds. Not tainted 4.19.0-rc8+ #69 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor4 D24704 1002 5520 0x00000004 Call Trace: context_switch kernel/sched/core.c:2825 [inline] __schedule+0x86c/0x1ed0 kernel/sched/core.c:3473 schedule+0xfe/0x460 kernel/sched/core.c:3517 d_wait_lookup fs/dcache.c:2428 [inline] d_alloc_parallel+0x1474/0x1f40 fs/dcache.c:2510 __lookup_slow+0x1e6/0x540 fs/namei.c:1654 lookup_slow+0x57/0x80 fs/namei.c:1688 walk_component+0x92b/0x25c0 fs/namei.c:1810 lookup_last fs/namei.c:2273 [inline] path_lookupat.isra.43+0x212/0xc00 fs/namei.c:2318 filename_lookup+0x26a/0x520 fs/namei.c:2348 user_path_at_empty+0x40/0x50 fs/namei.c:2608 user_path_at include/linux/namei.h:57 [inline] do_utimes+0x1d0/0x380 fs/utimes.c:152 do_futimesat+0x250/0x350 fs/utimes.c:212 __do_sys_utimes fs/utimes.c:225 [inline] __se_sys_utimes fs/utimes.c:222 [inline] __x64_sys_utimes+0x59/0x80 fs/utimes.c:222 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:00007f157e5e3c78 EFLAGS: 00000246 ORIG_RAX: 00000000000000eb RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 0000000000457569 RDX: 0000000000000000 RSI: 00000000200001c0 RDI: 0000000020000180 RBP: 000000000072c180 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f157e5e46d4 R13: 00000000004c4f46 R14: 00000000004d8508 R15: 00000000ffffffff Showing all locks held in the system: 1 lock held by khungtaskd/960: #0: 000000003758648f (rcu_read_lock){....}, at: debug_show_all_locks+0xd0/0x424 kernel/locking/lockdep.c:4435 1 lock held by rsyslogd/5288: #0: 00000000dd9f8604 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1bb/0x200 fs/file.c:766 2 locks held by getty/5378: #0: 00000000c76d9a8c (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 000000003729cd4e (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/5379: #0: 00000000c862e95b (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000a56d57b9 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/5380: #0: 000000004289141c (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000614f2345 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/5381: #0: 00000000611692e1 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000d4e39f9d (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/5382: #0: 000000001f1bcf1b (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000748b1b2e (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/5383: #0: 000000001e8f3f74 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000dc235d17 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/5384: #0: 0000000071a76a31 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 0000000090c8a0b4 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 1 lock held by syz-executor4/937: #0: 000000008c706e08 (&sb->s_type->i_mutex_key#21){++++}, at: inode_lock_shared include/linux/fs.h:748 [inline] #0: 000000008c706e08 (&sb->s_type->i_mutex_key#21){++++}, at: lookup_slow+0x49/0x80 fs/namei.c:1687 1 lock held by syz-executor4/1002: #0: 000000008c706e08 (&sb->s_type->i_mutex_key#21){++++}, at: inode_lock_shared include/linux/fs.h:748 [inline] #0: 000000008c706e08 (&sb->s_type->i_mutex_key#21){++++}, at: lookup_slow+0x49/0x80 fs/namei.c:1687 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 960 Comm: khungtaskd Not tainted 4.19.0-rc8+ #69 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+0x1c4/0x2b4 lib/dump_stack.c:113 nmi_cpu_backtrace.cold.3+0x63/0xa2 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1b3/0x1ed 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+0xb3e/0x1050 kernel/hung_task.c:265 kthread+0x35a/0x420 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:413 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 skipped: idling at native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:57