INFO: task syz-executor4:5476 blocked for more than 140 seconds. Not tainted 4.19.0-rc8+ #62 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor4 D14648 5476 1 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 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3575 __mutex_lock_common kernel/locking/mutex.c:1002 [inline] __mutex_lock+0xbe7/0x1700 kernel/locking/mutex.c:1072 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087 fuse_lock_inode+0xba/0xf0 fs/fuse/inode.c:365 fuse_lookup+0x8f/0x4c0 fs/fuse/dir.c:360 __lookup_slow+0x2b5/0x540 fs/namei.c:1671 lookup_slow+0x57/0x80 fs/namei.c:1688 walk_component+0x92b/0x25c0 fs/namei.c:1810 link_path_walk.part.40+0xa61/0x1530 fs/namei.c:2141 link_path_walk fs/namei.c:2072 [inline] path_openat+0x270/0x5160 fs/namei.c:3533 do_filp_open+0x255/0x380 fs/namei.c:3564 do_sys_open+0x568/0x700 fs/open.c:1063 __do_sys_open fs/open.c:1081 [inline] __se_sys_open fs/open.c:1076 [inline] __x64_sys_open+0x7e/0xc0 fs/open.c:1076 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x455570 Code: 00 48 8b ac 24 38 01 00 00 48 81 c4 40 01 00 00 c3 3c 18 75 18 c6 84 24 60 01 00 00 01 48 8b ac 24 38 01 00 00 48 81 c4 40 01 <00> 00 c3 3c 19 0f 85 61 03 00 00 48 8b 84 24 48 01 00 00 48 8b 48 RSP: 002b:00007fffec6dcd40 EFLAGS: 00000202 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000455570 RDX: 0000000000000000 RSI: 0000000000090800 RDI: 00000000004bc2ae RBP: 00000000000015f0 R08: 0000000000000001 R09: 000000000182f940 R10: 0000000000000000 R11: 0000000000000202 R12: 000000000000000e R13: 00000000001204ab R14: 0000000000000685 R15: 0000000000000004 INFO: task syz-executor4:23663 blocked for more than 140 seconds. Not tainted 4.19.0-rc8+ #62 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor4 D23144 23663 5476 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 request_wait_answer+0x4a6/0x900 fs/fuse/dev.c:474 __fuse_request_send+0x12a/0x1d0 fs/fuse/dev.c:494 fuse_request_send+0x62/0xa0 fs/fuse/dev.c:507 fuse_simple_request+0x33d/0x730 fs/fuse/dev.c:565 fuse_lookup_name+0x3ee/0x830 fs/fuse/dir.c:323 fuse_lookup+0xff/0x4c0 fs/fuse/dir.c:361 __lookup_slow+0x2b5/0x540 fs/namei.c:1671 lookup_slow+0x57/0x80 fs/namei.c:1688 walk_component+0x92b/0x25c0 fs/namei.c:1810 link_path_walk.part.40+0xa61/0x1530 fs/namei.c:2141 link_path_walk fs/namei.c:2072 [inline] path_openat+0x270/0x5160 fs/namei.c:3533 do_filp_open+0x255/0x380 fs/namei.c:3564 do_sys_open+0x568/0x700 fs/open.c:1063 __do_sys_openat fs/open.c:1090 [inline] __se_sys_openat fs/open.c:1084 [inline] __x64_sys_openat+0x9d/0x100 fs/open.c:1084 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457569 Code: 83 c4 18 c3 e8 d8 64 00 00 48 8b 04 24 48 8b 4c 24 08 48 89 01 e8 d7 2d fc ff e8 22 7a fc ff b8 02 00 00 00 48 8d 0d 2a 60 09 <01> 87 01 8b 05 22 60 09 01 83 f8 01 0f 85 8a 00 00 00 b8 01 00 00 RSP: 002b:00007f39e7597c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 0000000000457569 RDX: 0000000000000002 RSI: 0000000020000180 RDI: ffffffffffffff9c RBP: 000000000072bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f39e75986d4 R13: 00000000004c2b98 R14: 00000000004d4218 R15: 00000000ffffffff INFO: task syz-executor4:23668 blocked for more than 140 seconds. Not tainted 4.19.0-rc8+ #62 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor4 D24968 23668 5476 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 request_wait_answer+0x4a6/0x900 fs/fuse/dev.c:474 __fuse_request_send+0x12a/0x1d0 fs/fuse/dev.c:494 fuse_request_send+0x62/0xa0 fs/fuse/dev.c:507 fuse_simple_request+0x33d/0x730 fs/fuse/dev.c:565 fuse_listxattr+0x421/0x840 fs/fuse/xattr.c:139 vfs_listxattr+0x114/0x1a0 fs/xattr.c:355 listxattr+0x74/0x150 fs/xattr.c:617 path_listxattr+0xf5/0x1a0 fs/xattr.c:641 __do_sys_llistxattr fs/xattr.c:659 [inline] __se_sys_llistxattr fs/xattr.c:656 [inline] __x64_sys_llistxattr+0x75/0xb0 fs/xattr.c:656 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457569 Code: 83 c4 18 c3 e8 d8 64 00 00 48 8b 04 24 48 8b 4c 24 08 48 89 01 e8 d7 2d fc ff e8 22 7a fc ff b8 02 00 00 00 48 8d 0d 2a 60 09 <01> 87 01 8b 05 22 60 09 01 83 f8 01 0f 85 8a 00 00 00 b8 01 00 00 RSP: 002b:00007f39e7576c78 EFLAGS: 00000246 ORIG_RAX: 00000000000000c3 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457569 RDX: 0000000000000061 RSI: 0000000020000080 RDI: 00000000200001c0 RBP: 000000000072bfa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f39e75776d4 R13: 00000000004c26e1 R14: 00000000004d38a0 R15: 00000000ffffffff INFO: task syz-executor4:23714 blocked for more than 140 seconds. Not tainted 4.19.0-rc8+ #62 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor4 D23432 23714 5476 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 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3575 __mutex_lock_common kernel/locking/mutex.c:1002 [inline] __mutex_lock+0xbe7/0x1700 kernel/locking/mutex.c:1072 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087 fuse_lock_inode+0xba/0xf0 fs/fuse/inode.c:365 fuse_lookup+0x8f/0x4c0 fs/fuse/dir.c:360 __lookup_slow+0x2b5/0x540 fs/namei.c:1671 lookup_slow+0x57/0x80 fs/namei.c:1688 walk_component+0x92b/0x25c0 fs/namei.c:1810 link_path_walk.part.40+0xa61/0x1530 fs/namei.c:2141 link_path_walk fs/namei.c:2072 [inline] path_openat+0x270/0x5160 fs/namei.c:3533 do_filp_open+0x255/0x380 fs/namei.c:3564 do_sys_open+0x568/0x700 fs/open.c:1063 __do_sys_openat fs/open.c:1090 [inline] __se_sys_openat fs/open.c:1084 [inline] __x64_sys_openat+0x9d/0x100 fs/open.c:1084 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457569 Code: 83 c4 18 c3 e8 d8 64 00 00 48 8b 04 24 48 8b 4c 24 08 48 89 01 e8 d7 2d fc ff e8 22 7a fc ff b8 02 00 00 00 48 8d 0d 2a 60 09 <01> 87 01 8b 05 22 60 09 01 83 f8 01 0f 85 8a 00 00 00 b8 01 00 00 RSP: 002b:00007f39e7555c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 0000000000457569 RDX: 0000000000000002 RSI: 0000000020000340 RDI: ffffffffffffff9c RBP: 000000000072c040 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f39e75566d4 R13: 00000000004c2bd7 R14: 00000000004d4290 R15: 00000000ffffffff Showing all locks held in the system: 1 lock held by khungtaskd/545: #0: 00000000dc8e6298 (rcu_read_lock){....}, at: debug_show_all_locks+0xd0/0x424 kernel/locking/lockdep.c:4435 1 lock held by rsyslogd/5240: #0: 00000000bf679b7d (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1bb/0x200 fs/file.c:766 2 locks held by getty/5330: #0: 00000000e99d7a9e (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000dca23dca (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/5331: #0: 000000009d11a1b7 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 000000007b164cae (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/5332: #0: 00000000045246ed (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000db31ad59 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/5333: #0: 00000000371fa9ca (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000557b6970 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/5334: #0: 000000007dbcd8a2 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 000000005f819f14 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/5335: #0: 00000000fbc83f4d (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 0000000090c67f7d (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/5336: #0: 00000000f6167784 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 0000000001728750 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by syz-executor4/5476: #0: 00000000dd8411cb (&type->i_mutex_dir_key#8){++++}, at: inode_lock_shared include/linux/fs.h:748 [inline] #0: 00000000dd8411cb (&type->i_mutex_dir_key#8){++++}, at: lookup_slow+0x49/0x80 fs/namei.c:1687 #1: 00000000b96aafe9 (&fi->mutex){+.+.}, at: fuse_lock_inode+0xba/0xf0 fs/fuse/inode.c:365 2 locks held by syz-executor4/23663: #0: 00000000dd8411cb (&type->i_mutex_dir_key#8){++++}, at: inode_lock_shared include/linux/fs.h:748 [inline] #0: 00000000dd8411cb (&type->i_mutex_dir_key#8){++++}, at: lookup_slow+0x49/0x80 fs/namei.c:1687 #1: 00000000b96aafe9 (&fi->mutex){+.+.}, at: fuse_lock_inode+0xba/0xf0 fs/fuse/inode.c:365 2 locks held by syz-executor4/23714: #0: 00000000dd8411cb (&type->i_mutex_dir_key#8){++++}, at: inode_lock_shared include/linux/fs.h:748 [inline] #0: 00000000dd8411cb (&type->i_mutex_dir_key#8){++++}, at: lookup_slow+0x49/0x80 fs/namei.c:1687 #1: 00000000b96aafe9 (&fi->mutex){+.+.}, at: fuse_lock_inode+0xba/0xf0 fs/fuse/inode.c:365 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 545 Comm: khungtaskd Not tainted 4.19.0-rc8+ #62 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