INFO: task syz-executor7:12595 blocked for more than 140 seconds. Not tainted 4.18.0-rc4+ #139 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor7 D23120 12595 9294 0x00000004 Call Trace: context_switch kernel/sched/core.c:2853 [inline] __schedule+0x87c/0x1ed0 kernel/sched/core.c:3501 schedule+0xfb/0x450 kernel/sched/core.c:3545 __rwsem_down_read_failed_common kernel/locking/rwsem-xadd.c:269 [inline] rwsem_down_read_failed+0x362/0x600 kernel/locking/rwsem-xadd.c:286 call_rwsem_down_read_failed+0x18/0x30 arch/x86/lib/rwsem.S:94 __down_read arch/x86/include/asm/rwsem.h:83 [inline] __percpu_down_read+0x16e/0x210 kernel/locking/percpu-rwsem.c:85 percpu_down_read_preempt_disable include/linux/percpu-rwsem.h:49 [inline] percpu_down_read include/linux/percpu-rwsem.h:59 [inline] __sb_start_write+0x2d7/0x300 fs/super.c:1403 file_start_write include/linux/fs.h:2737 [inline] vfs_write+0x452/0x560 fs/read_write.c:548 ksys_write+0x101/0x260 fs/read_write.c:598 __do_sys_write fs/read_write.c:610 [inline] __se_sys_write fs/read_write.c:607 [inline] __x64_sys_write+0x73/0xb0 fs/read_write.c:607 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x455e29 Code: cc 64 48 8b 0c 25 f8 ff ff ff 48 3b 61 10 0f 86 ab 04 00 00 48 83 ec 58 48 89 6c 24 50 48 8d 6c 24 50 48 8b 44 24 60 c6 00 00 <48> 8b 4c 24 68 48 89 ca 48 89 50 08 48 8b 59 20 48 01 da 31 db 31 RSP: 002b:00007f6eb478ec68 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f6eb478f6d4 RCX: 0000000000455e29 RDX: 0000000000000030 RSI: 0000000020011fd2 RDI: 0000000000000014 RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000004c2f67 R14: 00000000004d4d98 R15: 0000000000000000 INFO: task syz-executor7:12637 blocked for more than 140 seconds. Not tainted 4.18.0-rc4+ #139 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor7 D23208 12637 9294 0x00000004 Call Trace: context_switch kernel/sched/core.c:2853 [inline] __schedule+0x87c/0x1ed0 kernel/sched/core.c:3501 schedule+0xfb/0x450 kernel/sched/core.c:3545 __rwsem_down_read_failed_common kernel/locking/rwsem-xadd.c:269 [inline] rwsem_down_read_failed+0x362/0x600 kernel/locking/rwsem-xadd.c:286 call_rwsem_down_read_failed+0x18/0x30 arch/x86/lib/rwsem.S:94 __down_read arch/x86/include/asm/rwsem.h:83 [inline] __percpu_down_read+0x16e/0x210 kernel/locking/percpu-rwsem.c:85 percpu_down_read_preempt_disable include/linux/percpu-rwsem.h:49 [inline] percpu_down_read include/linux/percpu-rwsem.h:59 [inline] __sb_start_write+0x2d7/0x300 fs/super.c:1403 sb_start_write include/linux/fs.h:1554 [inline] mnt_want_write+0x3f/0xc0 fs/namespace.c:386 do_last fs/namei.c:3298 [inline] path_openat+0x26a3/0x4e10 fs/namei.c:3540 do_filp_open+0x255/0x380 fs/namei.c:3574 do_sys_open+0x584/0x760 fs/open.c:1101 ksys_open include/linux/syscalls.h:1274 [inline] __do_sys_creat fs/open.c:1159 [inline] __se_sys_creat fs/open.c:1157 [inline] __x64_sys_creat+0x61/0x80 fs/open.c:1157 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x455e29 Code: cc 64 48 8b 0c 25 f8 ff ff ff 48 3b 61 10 0f 86 ab 04 00 00 48 83 ec 58 48 89 6c 24 50 48 8d 6c 24 50 48 8b 44 24 60 c6 00 00 <48> 8b 4c 24 68 48 89 ca 48 89 50 08 48 8b 59 20 48 01 da 31 db 31 RSP: 002b:00007f6eb474cc68 EFLAGS: 00000246 ORIG_RAX: 0000000000000055 RAX: ffffffffffffffda RBX: 00007f6eb474d6d4 RCX: 0000000000455e29 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000000002009aff8 RBP: 000000000072bff0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000004bbd75 R14: 00000000004c9188 R15: 0000000000000002 INFO: task syz-executor0:12639 blocked for more than 140 seconds. Not tainted 4.18.0-rc4+ #139 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor0 D22696 12639 4558 0x00000004 Call Trace: context_switch kernel/sched/core.c:2853 [inline] __schedule+0x87c/0x1ed0 kernel/sched/core.c:3501 schedule+0xfb/0x450 kernel/sched/core.c:3545 __rwsem_down_read_failed_common kernel/locking/rwsem-xadd.c:269 [inline] rwsem_down_read_failed+0x362/0x600 kernel/locking/rwsem-xadd.c:286 call_rwsem_down_read_failed+0x18/0x30 arch/x86/lib/rwsem.S:94 __down_read arch/x86/include/asm/rwsem.h:83 [inline] __percpu_down_read+0x16e/0x210 kernel/locking/percpu-rwsem.c:85 percpu_down_read_preempt_disable include/linux/percpu-rwsem.h:49 [inline] percpu_down_read include/linux/percpu-rwsem.h:59 [inline] __sb_start_write+0x2d7/0x300 fs/super.c:1403 sb_start_write include/linux/fs.h:1554 [inline] mnt_want_write_file+0x123/0x330 fs/namespace.c:497 ext4_ioctl+0x1b97/0x4210 fs/ext4/ioctl.c:694 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0x1de/0x1720 fs/ioctl.c:684 ksys_ioctl+0xa9/0xd0 fs/ioctl.c:701 __do_sys_ioctl fs/ioctl.c:708 [inline] __se_sys_ioctl fs/ioctl.c:706 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:706 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x455e29 Code: cc 64 48 8b 0c 25 f8 ff ff ff 48 3b 61 10 0f 86 ab 04 00 00 48 83 ec 58 48 89 6c 24 50 48 8d 6c 24 50 48 8b 44 24 60 c6 00 00 <48> 8b 4c 24 68 48 89 ca 48 89 50 08 48 8b 59 20 48 01 da 31 db 31 RSP: 002b:00007fbff2797c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fbff27986d4 RCX: 0000000000455e29 RDX: 0000000020000040 RSI: 0000000040087602 RDI: 0000000000000014 RBP: 000000000072bf48 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000004bd78d R14: 00000000004cbe70 R15: 0000000000000001 Showing all locks held in the system: 1 lock held by khungtaskd/901: #0: 000000000f11074e (rcu_read_lock){....}, at: debug_show_all_locks+0xd0/0x428 kernel/locking/lockdep.c:4461 2 locks held by rs:main Q:Reg/4421: #0: 0000000015fda81d (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1bb/0x200 fs/file.c:766 #1: 00000000e9b30dc9 (sb_writers#6){++++}, at: file_start_write include/linux/fs.h:2737 [inline] #1: 00000000e9b30dc9 (sb_writers#6){++++}, at: vfs_write+0x452/0x560 fs/read_write.c:548 1 lock held by rsyslogd/4423: #0: 00000000e90c9559 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1bb/0x200 fs/file.c:766 2 locks held by getty/4513: #0: 00000000ae46c1ea (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000c66a67f7 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4514: #0: 00000000bed6c706 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000d1cd0055 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4515: #0: 0000000009b995b1 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 0000000053321102 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4516: #0: 000000001473218a (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000f5e2f8ad (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4517: #0: 00000000459f0e1d (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000c09548e9 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4518: #0: 000000001e0245b5 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 000000001103d49a (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4519: #0: 000000000dcef7ea (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000b1a34a2a (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by syz-executor7/12595: #0: 00000000d724b631 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1bb/0x200 fs/file.c:766 #1: 00000000e9b30dc9 (sb_writers#6){++++}, at: file_start_write include/linux/fs.h:2737 [inline] #1: 00000000e9b30dc9 (sb_writers#6){++++}, at: vfs_write+0x452/0x560 fs/read_write.c:548 1 lock held by syz-executor7/12637: #0: 00000000e9b30dc9 (sb_writers#6){++++}, at: sb_start_write include/linux/fs.h:1554 [inline] #0: 00000000e9b30dc9 (sb_writers#6){++++}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:386 1 lock held by syz-executor0/12639: #0: 00000000e9b30dc9 (sb_writers#6){++++}, at: sb_start_write include/linux/fs.h:1554 [inline] #0: 00000000e9b30dc9 (sb_writers#6){++++}, at: mnt_want_write_file+0x123/0x330 fs/namespace.c:497 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 901 Comm: khungtaskd Not tainted 4.18.0-rc4+ #139 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 1 to CPUs 0: NMI backtrace for cpu 0 skipped: idling at native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:54