random: sshd: uninitialized urandom read (32 bytes read) random: sshd: uninitialized urandom read (32 bytes read) random: sshd: uninitialized urandom read (32 bytes read) random: sshd: uninitialized urandom read (32 bytes read) random: sshd: uninitialized urandom read (32 bytes read) INFO: task syz-executor842:4559 blocked for more than 140 seconds. Not tainted 4.18.0-rc6+ #160 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor842 D23528 4559 4556 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_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] fuse_reverse_inval_entry+0xae/0x6d0 fs/fuse/dir.c:969 fuse_notify_inval_entry fs/fuse/dev.c:1491 [inline] fuse_notify fs/fuse/dev.c:1764 [inline] fuse_dev_do_write+0x2b97/0x3700 fs/fuse/dev.c:1848 fuse_dev_write+0x19a/0x240 fs/fuse/dev.c:1928 call_write_iter include/linux/fs.h:1793 [inline] new_sync_write fs/read_write.c:474 [inline] __vfs_write+0x6c6/0x9f0 fs/read_write.c:487 vfs_write+0x1f8/0x560 fs/read_write.c:549 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: 0033:0x445869 Code: Bad RIP value. RSP: 002b:00007ffa2ef7fda8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00000000006dac24 RCX: 0000000000445869 RDX: 0000000000000029 RSI: 00000000200000c0 RDI: 0000000000000003 RBP: 00000000006dac20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0030656c69662f2e R13: 64695f70756f7267 R14: 2f30656c69662f2e R15: 0000000000000001 INFO: task syz-executor842:4560 blocked for more than 140 seconds. Not tainted 4.18.0-rc6+ #160 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor842 D26008 4560 4556 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 request_wait_answer+0x4c8/0x920 fs/fuse/dev.c:463 __fuse_request_send+0x12a/0x1d0 fs/fuse/dev.c:483 fuse_request_send+0x62/0xa0 fs/fuse/dev.c:496 fuse_simple_request+0x33d/0x730 fs/fuse/dev.c:554 fuse_lookup_name+0x3ee/0x830 fs/fuse/dir.c:323 fuse_lookup+0xf9/0x4c0 fs/fuse/dir.c:360 __lookup_hash+0x12e/0x190 fs/namei.c:1505 filename_create+0x1e5/0x5b0 fs/namei.c:3646 user_path_create fs/namei.c:3703 [inline] do_mkdirat+0xda/0x310 fs/namei.c:3842 __do_sys_mkdirat fs/namei.c:3861 [inline] __se_sys_mkdirat fs/namei.c:3859 [inline] __x64_sys_mkdirat+0x76/0xb0 fs/namei.c:3859 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x445869 Code: Bad RIP value. RSP: 002b:00007ffa2ef5eda8 EFLAGS: 00000297 ORIG_RAX: 0000000000000102 RAX: ffffffffffffffda RBX: 00000000006dac3c RCX: 0000000000445869 RDX: 0000000000000000 RSI: 0000000020000500 RDI: 00000000ffffff9c RBP: 00000000006dac38 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000297 R12: 0030656c69662f2e R13: 64695f70756f7267 R14: 2f30656c69662f2e R15: 0000000000000001 Showing all locks held in the system: 1 lock held by khungtaskd/901: #0: (____ptrval____) (rcu_read_lock){....}, at: debug_show_all_locks+0xd0/0x428 kernel/locking/lockdep.c:4461 1 lock held by rsyslogd/4441: #0: (____ptrval____) (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1bb/0x200 fs/file.c:766 2 locks held by getty/4531: #0: (____ptrval____) (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (____ptrval____) (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4532: #0: (____ptrval____) (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (____ptrval____) (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4533: #0: (____ptrval____) (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (____ptrval____) (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4534: #0: (____ptrval____) (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (____ptrval____) (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4535: #0: (____ptrval____) (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (____ptrval____) (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4536: #0: (____ptrval____) (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (____ptrval____) (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4537: #0: (____ptrval____) (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (____ptrval____) (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by syz-executor842/4559: #0: (____ptrval____) (&fc->killsb){.+.+}, at: fuse_notify_inval_entry fs/fuse/dev.c:1488 [inline] #0: (____ptrval____) (&fc->killsb){.+.+}, at: fuse_notify fs/fuse/dev.c:1764 [inline] #0: (____ptrval____) (&fc->killsb){.+.+}, at: fuse_dev_do_write+0x2b2d/0x3700 fs/fuse/dev.c:1848 #1: (____ptrval____) (&type->i_mutex_dir_key#4){+.+.}, at: inode_lock include/linux/fs.h:715 [inline] #1: (____ptrval____) (&type->i_mutex_dir_key#4){+.+.}, at: fuse_reverse_inval_entry+0xae/0x6d0 fs/fuse/dir.c:969 3 locks held by syz-executor842/4560: #0: (____ptrval____) (sb_writers#9){.+.+}, at: sb_start_write include/linux/fs.h:1554 [inline] #0: (____ptrval____) (sb_writers#9){.+.+}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:386 #1: (____ptrval____) (&type->i_mutex_dir_key#3/1){+.+.}, at: inode_lock_nested include/linux/fs.h:750 [inline] #1: (____ptrval____) (&type->i_mutex_dir_key#3/1){+.+.}, at: filename_create+0x1b2/0x5b0 fs/namei.c:3645 #2: (____ptrval____) (&fi->mutex){+.+.}, at: fuse_lock_inode+0xaf/0xe0 fs/fuse/inode.c:363 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 901 Comm: khungtaskd Not tainted 4.18.0-rc6+ #160 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