INFO: task syz-executor4:12910 blocked for more than 140 seconds. Not tainted 4.19.0-rc8+ #74 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor4 D22952 12910 5607 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_access+0x36a/0x500 fs/fuse/dir.c:1082 fuse_permission+0x327/0x530 fs/fuse/dir.c:1154 do_inode_permission fs/namei.c:386 [inline] inode_permission+0x35e/0x560 fs/namei.c:451 ksys_chroot+0x10a/0x2e0 fs/open.c:496 __do_sys_chroot fs/open.c:521 [inline] __se_sys_chroot fs/open.c:519 [inline] __x64_sys_chroot+0x31/0x40 fs/open.c:519 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:00007fb999fc9c78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a1 RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 0000000000457569 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000000 RBP: 000000000072bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fb999fca6d4 R13: 00000000004bd998 R14: 00000000004cc3b8 R15: 00000000ffffffff INFO: task syz-executor4:12923 blocked for more than 140 seconds. Not tainted 4.19.0-rc8+ #74 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor4 D25632 12923 5607 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: Bad RIP value. RSP: 002b:00007fb999f87c78 EFLAGS: 00000246 ORIG_RAX: 00000000000000c3 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457569 RDX: 00000000000000de RSI: 0000000020000480 RDI: 0000000020000240 RBP: 000000000072c040 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fb999f886d4 R13: 00000000004c26e1 R14: 00000000004d38a0 R15: 00000000ffffffff Showing all locks held in the system: 1 lock held by khungtaskd/982: #0: 00000000c139a831 (rcu_read_lock){....}, at: debug_show_all_locks+0xd0/0x424 kernel/locking/lockdep.c:4435 2 locks held by rsyslogd/5355: #0: 00000000b8835b5f (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1bb/0x200 fs/file.c:766 #1: 000000000187fb08 (&rq->lock){-.-.}, at: rq_lock kernel/sched/sched.h:1824 [inline] #1: 000000000187fb08 (&rq->lock){-.-.}, at: __schedule+0x236/0x1ed0 kernel/sched/core.c:3411 2 locks held by getty/5479: #0: 000000003738f86a (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 000000006684cbde (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/5480: #0: 0000000035280aab (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 000000001c752aaa (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/5481: #0: 00000000a983cf42 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000e06d2118 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/5482: #0: 00000000132c06b2 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 000000004744c886 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/5483: #0: 000000001aeffe7e (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 0000000028bfec9d (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/5484: #0: 000000007476d7d7 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000e038aae5 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/5485: #0: 00000000219a163c (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000620f3db8 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 982 Comm: khungtaskd Not tainted 4.19.0-rc8+ #74 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+0x1c4/0x2b6 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 1 to CPUs 0: NMI backtrace for cpu 0 skipped: idling at native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:57