input: syz1 as /devices/virtual/input/input223 input: syz1 as /devices/virtual/input/input224 INFO: task syz-executor.0:32406 blocked for more than 140 seconds. Not tainted 4.9.165+ #27 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D28808 32406 4318 0x00000004 ffff8801a443c740 ffff8801a011a680 ffff8801db721000 ffff8801a471df00 ffff8801db721018 ffff8801ac71f8c0 ffffffff827fbcce ffffffff82807255 ffff8801cc92ea48 00ff8801ac71f810 ffff8801db7218f0 1ffff100358e3f07 Call Trace: [] schedule+0x92/0x1c0 kernel/sched/core.c:3546 [] __rwsem_down_write_failed_common kernel/locking/rwsem-xadd.c:533 [inline] [] rwsem_down_write_failed+0x3a3/0x750 kernel/locking/rwsem-xadd.c:562 [] call_rwsem_down_write_failed+0x17/0x30 arch/x86/lib/rwsem.S:105 [] __down_write arch/x86/include/asm/rwsem.h:125 [inline] [] down_write+0x5c/0xa0 kernel/locking/rwsem.c:54 [] inode_lock include/linux/fs.h:768 [inline] [] do_last fs/namei.c:3353 [inline] [] path_openat+0xe4b/0x2f60 fs/namei.c:3581 [] do_filp_open+0x1a1/0x280 fs/namei.c:3615 [] do_sys_open+0x2f0/0x610 fs/open.c:1072 [] SYSC_open fs/open.c:1090 [inline] [] SyS_open fs/open.c:1085 [inline] [] SYSC_creat fs/open.c:1110 [inline] [] SyS_creat+0x27/0x30 fs/open.c:1108 [] do_syscall_64+0x1ad/0x570 arch/x86/entry/common.c:285 [] entry_SYSCALL_64_after_swapgs+0x5d/0xdb Showing all locks held in the system: 2 locks held by khungtaskd/24: #0: (rcu_read_lock){......}, at: [] check_hung_uninterruptible_tasks kernel/hung_task.c:168 [inline] #0: (rcu_read_lock){......}, at: [] watchdog+0x13c/0xae0 kernel/hung_task.c:239 #1: (tasklist_lock){.+.+..}, at: [] debug_show_all_locks+0x7f/0x21f kernel/locking/lockdep.c:4336 2 locks held by getty/2040: #0: (&tty->ldisc_sem){++++++}, at: [] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:377 #1: (&ldata->atomic_read_lock){+.+...}, at: [] n_tty_read+0x1fe/0x1820 drivers/tty/n_tty.c:2156 2 locks held by syz-executor.0/32406: #0: (sb_writers#4){.+.+.+}, at: [] sb_start_write include/linux/fs.h:1575 [inline] #0: (sb_writers#4){.+.+.+}, at: [] mnt_want_write+0x3f/0xb0 fs/namespace.c:391 #1: (&type->i_mutex_dir_key#3){++++++}, at: [] inode_lock include/linux/fs.h:768 [inline] #1: (&type->i_mutex_dir_key#3){++++++}, at: [] do_last fs/namei.c:3353 [inline] #1: (&type->i_mutex_dir_key#3){++++++}, at: [] path_openat+0xe4b/0x2f60 fs/namei.c:3581 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 24 Comm: khungtaskd Not tainted 4.9.165+ #27 ffff8801d98d7cc8 ffffffff81b4ba01 0000000000000001 0000000000000000 0000000000000001 ffffffff81097401 dffffc0000000000 ffff8801d98d7d00 ffffffff81b56c8c 0000000000000001 0000000000000000 0000000000000001 Call Trace: [] __dump_stack lib/dump_stack.c:15 [inline] [] dump_stack+0xc1/0x120 lib/dump_stack.c:51 [] nmi_cpu_backtrace.cold+0x47/0x87 lib/nmi_backtrace.c:99 [] nmi_trigger_cpumask_backtrace+0x124/0x155 lib/nmi_backtrace.c:60 [] arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:37 [] trigger_all_cpu_backtrace include/linux/nmi.h:58 [inline] [] check_hung_task kernel/hung_task.c:125 [inline] [] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline] [] watchdog+0x661/0xae0 kernel/hung_task.c:239 [] kthread+0x278/0x310 kernel/kthread.c:211 [] ret_from_fork+0x5c/0x70 arch/x86/entry/entry_64.S:373 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 skipped: idling at pc 0xffffffff8280ad42