INFO: task syz-executor0:10606 blocked for more than 140 seconds. Not tainted 4.18.0-rc8+ #180 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor0 D25408 10606 4471 0x00000004 Call Trace: context_switch kernel/sched/core.c:2853 [inline] __schedule+0x87c/0x1ec0 kernel/sched/core.c:3501 schedule+0xfb/0x450 kernel/sched/core.c:3545 __rwsem_down_write_failed_common+0x95d/0x1630 kernel/locking/rwsem-xadd.c:566 rwsem_down_write_failed+0xe/0x10 kernel/locking/rwsem-xadd.c:595 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+0xaa/0x130 kernel/locking/rwsem.c:72 inode_lock include/linux/fs.h:715 [inline] utimes_common.isra.1+0x45c/0x8e0 fs/utimes.c:90 do_utimes+0x1f7/0x380 fs/utimes.c:156 do_futimesat+0x249/0x350 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: 0033:0x456cb9 Code: 18 85 c0 75 12 48 8b 44 24 20 48 89 08 48 8b 6c 24 28 48 83 c4 30 c3 48 8b 44 24 20 48 89 04 24 48 89 4c 24 08 e8 e7 ac fb ff e1 e8 f0 31 00 00 e9 7b ff ff ff cc cc cc cc cc cc cc cc cc cc RSP: 002b:00007fdd07929c78 EFLAGS: 00000246 ORIG_RAX: 00000000000000eb RAX: ffffffffffffffda RBX: 00007fdd0792a6d4 RCX: 0000000000456cb9 RDX: 0000000000000000 RSI: 00000000200001c0 RDI: 0000000020000180 RBP: 00000000009301e0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000004d6450 R14: 00000000004c9b00 R15: 0000000000000002 Showing all locks held in the system: 1 lock held by khungtaskd/774: #0: 00000000fe73f861 (rcu_read_lock){....}, at: debug_show_all_locks+0xd0/0x428 kernel/locking/lockdep.c:4461 1 lock held by rsyslogd/4333: 2 locks held by getty/4424: #0: 0000000094d6a38e (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 0000000084b001a3 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4425: #0: 00000000b1cd11e7 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000864215c1 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4426: #0: 00000000ff123542 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000fbc9701d (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4427: #0: 000000004d1e51b9 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 0000000050e30ef2 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4428: #0: 0000000047556dc2 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000d819f80a (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4429: #0: 00000000beef994c (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000743f4a93 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4430: #0: 00000000ec126d5c (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 000000005468c746 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by syz-executor0/10537: #0: 0000000056091d24 (sb_writers#16){.+.+}, at: sb_start_write include/linux/fs.h:1554 [inline] #0: 0000000056091d24 (sb_writers#16){.+.+}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:386 #1: 0000000081e3b53d (&sb->s_type->i_mutex_key#18){++++}, at: inode_lock include/linux/fs.h:715 [inline] #1: 0000000081e3b53d (&sb->s_type->i_mutex_key#18){++++}, at: utimes_common.isra.1+0x45c/0x8e0 fs/utimes.c:90 2 locks held by syz-executor0/10606: #0: 0000000056091d24 (sb_writers#16){.+.+}, at: sb_start_write include/linux/fs.h:1554 [inline] #0: 0000000056091d24 (sb_writers#16){.+.+}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:386 #1: 0000000081e3b53d (&sb->s_type->i_mutex_key#18){++++}, at: inode_lock include/linux/fs.h:715 [inline] #1: 0000000081e3b53d (&sb->s_type->i_mutex_key#18){++++}, at: utimes_common.isra.1+0x45c/0x8e0 fs/utimes.c:90 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 774 Comm: khungtaskd Not tainted 4.18.0-rc8+ #180 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+0x1c9/0x2b4 lib/dump_stack.c:113 nmi_cpu_backtrace.cold.4+0x19/0xce lib/nmi_backtrace.c:103 nmi_trigger_cpumask_backtrace+0x151/0x192 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:138 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:196 [inline] watchdog+0x9c4/0xf80 kernel/hung_task.c:252 kthread+0x345/0x410 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:412 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:54