ISOFS: Unable to identify CD-ROM format. Unknown ioctl 1074294798 INFO: task syz-executor4:12954 blocked for more than 140 seconds. Not tainted 4.18.0-rc8+ #183 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor4 D24576 12954 4422 0x00000004 Call Trace: context_switch kernel/sched/core.c:2853 [inline] __schedule+0x87c/0x1ec0 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] vfs_removexattr+0x82/0x1c0 fs/xattr.c:391 removexattr+0xd3/0x130 fs/xattr.c:691 path_removexattr+0x1b9/0x210 fs/xattr.c:705 __do_sys_removexattr fs/xattr.c:719 [inline] __se_sys_removexattr fs/xattr.c:716 [inline] __x64_sys_removexattr+0x59/0x80 fs/xattr.c:716 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457089 Code: 08 e8 3b a9 fb ff 48 8b 44 24 20 48 8b 4c 24 18 48 8b 54 24 38 48 8b 7c 24 48 eb 8d 48 8b 6c 24 50 48 83 c4 58 c3 48 89 04 24 <48> 89 5c 24 08 e8 0d a9 fb ff 48 8b 44 24 40 48 8b 4c 24 48 48 8b RSP: 002b:00007fbc28d50c78 EFLAGS: 00000246 ORIG_RAX: 00000000000000c5 RAX: ffffffffffffffda RBX: 00007fbc28d516d4 RCX: 0000000000457089 RDX: 0000000000000000 RSI: 0000000020000180 RDI: 0000000020000080 RBP: 0000000000930140 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000004d3408 R14: 00000000004c3451 R15: 0000000000000001 Showing all locks held in the system: 1 lock held by khungtaskd/774: #0: 000000003a8bafe8 (rcu_read_lock){....}, at: debug_show_all_locks+0xd0/0x428 kernel/locking/lockdep.c:4461 3 locks held by rsyslogd/4281: 2 locks held by getty/4371: #0: 0000000035b0d981 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000fcd27c6d (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4372: #0: 00000000e777641d (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 000000001fe04640 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4373: #0: 00000000ab604bb3 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000932256fe (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4374: #0: 00000000dbfed4a0 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 000000003eb6245a (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4375: #0: 00000000c9ebf46a (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000cbb59956 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4376: #0: 0000000075211740 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000c9ba6aa9 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4377: #0: 00000000dd77078a (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 0000000086a765d0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by syz-executor4/12947: #0: 00000000295c8bf0 (sb_writers#17){.+.+}, at: sb_start_write include/linux/fs.h:1554 [inline] #0: 00000000295c8bf0 (sb_writers#17){.+.+}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:386 #1: 0000000013e76334 (&sb->s_type->i_mutex_key#23){++++}, at: inode_lock include/linux/fs.h:715 [inline] #1: 0000000013e76334 (&sb->s_type->i_mutex_key#23){++++}, at: vfs_removexattr+0x82/0x1c0 fs/xattr.c:391 2 locks held by syz-executor4/12954: #0: 00000000295c8bf0 (sb_writers#17){.+.+}, at: sb_start_write include/linux/fs.h:1554 [inline] #0: 00000000295c8bf0 (sb_writers#17){.+.+}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:386 #1: 0000000013e76334 (&sb->s_type->i_mutex_key#23){++++}, at: inode_lock include/linux/fs.h:715 [inline] #1: 0000000013e76334 (&sb->s_type->i_mutex_key#23){++++}, at: vfs_removexattr+0x82/0x1c0 fs/xattr.c:391 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 774 Comm: khungtaskd Not tainted 4.18.0-rc8+ #183 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 0 to CPUs 1: NMI backtrace for cpu 1 skipped: idling at native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:54