`)n"oeVu y؝ŴZͫ) failed (rc=-13) INFO: task syz-executor7:25192 blocked for more than 120 seconds. Not tainted 4.15.0-rc6+ #245 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor7 D22496 25192 3728 0x00000004 Call Trace: context_switch kernel/sched/core.c:2799 [inline] __schedule+0x8eb/0x2060 kernel/sched/core.c:3375 schedule+0xf5/0x430 kernel/sched/core.c:3434 schedule_preempt_disabled+0x10/0x20 kernel/sched/core.c:3492 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0xaad/0x1a80 kernel/locking/mutex.c:893 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908 lo_open+0x1b/0xa0 drivers/block/loop.c:1571 __blkdev_get+0x2f9/0x10e0 fs/block_dev.c:1454 blkdev_get+0x3a1/0xad0 fs/block_dev.c:1591 blkdev_open+0x1c9/0x250 fs/block_dev.c:1749 do_dentry_open+0x667/0xd40 fs/open.c:752 vfs_open+0x107/0x220 fs/open.c:866 do_last fs/namei.c:3379 [inline] path_openat+0x1151/0x3530 fs/namei.c:3519 do_filp_open+0x25b/0x3b0 fs/namei.c:3554 do_sys_open+0x502/0x6d0 fs/open.c:1059 SYSC_open fs/open.c:1077 [inline] SyS_open+0x2d/0x40 fs/open.c:1072 entry_SYSCALL_64_fastpath+0x23/0x9a RIP: 0033:0x40ce01 RSP: 002b:00007f30e159e780 EFLAGS: 00000293 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 000000000071bea0 RCX: 000000000040ce01 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00007f30e159e830 RBP: 000000000000025d R08: 0000000000000000 R09: 0000000000000000 R10: 000000000000000c R11: 0000000000000293 R12: 00000000006f1958 R13: 00000000ffffffff R14: 00007f30e159f6d4 R15: 0000000000000000 Showing all locks held in the system: 2 locks held by khungtaskd/737: #0: (rcu_read_lock){....}, at: [<000000006f908f39>] check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline] #0: (rcu_read_lock){....}, at: [<000000006f908f39>] watchdog+0x1c5/0xd60 kernel/hung_task.c:249 #1: (tasklist_lock){.+.+}, at: [<00000000042f9077>] debug_show_all_locks+0xd3/0x400 kernel/locking/lockdep.c:4464 4 locks held by rs:main Q:Reg/3342: #0: (&f->f_pos_lock){+.+.}, at: [<00000000f853dcac>] __fdget_pos+0x12b/0x190 fs/file.c:770 #1: (sb_writers#4){.+.+}, at: [<000000008a38b9bd>] file_start_write include/linux/fs.h:2715 [inline] #1: (sb_writers#4){.+.+}, at: [<000000008a38b9bd>] vfs_write+0x407/0x510 fs/read_write.c:543 #2: (&sb->s_type->i_mutex_key#10){+.+.}, at: [<000000009f8ae320>] inode_trylock include/linux/fs.h:733 [inline] #2: (&sb->s_type->i_mutex_key#10){+.+.}, at: [<000000009f8ae320>] ext4_file_write_iter+0x21f/0x10c0 fs/ext4/file.c:232 #3: (jbd2_handle){++++}, at: [<0000000006f22b2b>] start_this_handle+0x488/0x1080 fs/jbd2/transaction.c:388 2 locks held by getty/3466: #0: (&tty->ldisc_sem){++++}, at: [<000000009cd8de47>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<000000009edb5910>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131 2 locks held by getty/3467: #0: (&tty->ldisc_sem){++++}, at: [<000000009cd8de47>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<000000009edb5910>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131 2 locks held by getty/3468: #0: (&tty->ldisc_sem){++++}, at: [<000000009cd8de47>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<000000009edb5910>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131 2 locks held by getty/3469: #0: (&tty->ldisc_sem){++++}, at: [<000000009cd8de47>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<000000009edb5910>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131 2 locks held by getty/3470: #0: (&tty->ldisc_sem){++++}, at: [<000000009cd8de47>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<000000009edb5910>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131 2 locks held by getty/3471: #0: (&tty->ldisc_sem){++++}, at: [<000000009cd8de47>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<000000009edb5910>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131 2 locks held by getty/3472: #0: (&tty->ldisc_sem){++++}, at: [<000000009cd8de47>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<000000009edb5910>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131 2 locks held by syz-executor7/25192: #0: (&bdev->bd_mutex){+.+.}, at: [<00000000ef13ac42>] __blkdev_get+0x158/0x10e0 fs/block_dev.c:1439 #1: (loop_index_mutex){+.+.}, at: [<000000004ed20a48>] lo_open+0x1b/0xa0 drivers/block/loop.c:1571 2 locks held by syz-executor7/25210: #0: (&lo->lo_ctl_mutex/1){+.+.}, at: [<00000000009f4182>] lo_ioctl+0x8b/0x1b70 drivers/block/loop.c:1355 #1: (&bdev->bd_mutex){+.+.}, at: [<0000000064a7467e>] blkdev_reread_part+0x1e/0x40 block/ioctl.c:192 1 lock held by syz-executor7/25223: #0: (&bdev->bd_mutex){+.+.}, at: [<00000000ef13ac42>] __blkdev_get+0x158/0x10e0 fs/block_dev.c:1439 1 lock held by syz-executor7/25226: #0: (&lo->lo_ctl_mutex/1){+.+.}, at: [<00000000009f4182>] lo_ioctl+0x8b/0x1b70 drivers/block/loop.c:1355 1 lock held by syz-executor7/25228: #0: (&lo->lo_ctl_mutex/1){+.+.}, at: [<00000000009f4182>] lo_ioctl+0x8b/0x1b70 drivers/block/loop.c:1355 1 lock held by syz-executor7/25230: #0: (&lo->lo_ctl_mutex/1){+.+.}, at: [<00000000009f4182>] lo_ioctl+0x8b/0x1b70 drivers/block/loop.c:1355 1 lock held by syz-executor7/25231: #0: (&bdev->bd_mutex){+.+.}, at: [<00000000ef13ac42>] __blkdev_get+0x158/0x10e0 fs/block_dev.c:1439 2 locks held by blkid/25205: #0: (&bdev->bd_mutex){+.+.}, at: [<00000000ef13ac42>] __blkdev_get+0x158/0x10e0 fs/block_dev.c:1439 #1: (loop_index_mutex){+.+.}, at: [<000000004ed20a48>] lo_open+0x1b/0xa0 drivers/block/loop.c:1571 2 locks held by syz-executor1/25213: #0: (loop_index_mutex){+.+.}, at: [<0000000037185579>] loop_control_ioctl+0x89/0x490 drivers/block/loop.c:1932 #1: (&lo->lo_ctl_mutex#2){+.+.}, at: [<00000000907fc6ab>] loop_control_ioctl+0x1a7/0x490 drivers/block/loop.c:1946 1 lock held by syz-executor1/25221: #0: (loop_index_mutex){+.+.}, at: [<0000000037185579>] loop_control_ioctl+0x89/0x490 drivers/block/loop.c:1932 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 737 Comm: khungtaskd Not tainted 4.15.0-rc6+ #245 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x194/0x257 lib/dump_stack.c:53 nmi_cpu_backtrace+0x1d2/0x210 lib/nmi_backtrace.c:103 nmi_trigger_cpumask_backtrace+0x122/0x180 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_task kernel/hung_task.c:132 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:190 [inline] watchdog+0x90c/0xd60 kernel/hung_task.c:249 kthread+0x33c/0x400 kernel/kthread.c:238 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:524 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.15.0-rc6+ #245 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:apic_eoi arch/x86/include/asm/apic.h:406 [inline] RIP: 0010:ack_APIC_irq arch/x86/include/asm/apic.h:450 [inline] RIP: 0010:smp_reschedule_interrupt+0xa2/0x670 arch/x86/kernel/smp.c:262 RSP: 0018:ffff8801db307ea0 EFLAGS: 00000046 RAX: 1ffffffff0ccc62c RBX: 1ffff1003b660fd4 RCX: 0000000000000000 RDX: dffffc0000000000 RSI: 0000000000000001 RDI: ffffffff86663160 RBP: ffff8801db307fe8 R08: ffffffff86662ae8 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000001 R13: ffff8801db307fc0 R14: ffffffff8702ffa0 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000002059000 CR3: 0000000006822001 CR4: 00000000001606e0 Call Trace: reschedule_interrupt+0xa9/0xb0 arch/x86/entry/entry_64.S:944 RIP: 0010:native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:54 RSP: 0018:ffff8801d9f77cb0 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff02 RAX: dffffc0000000000 RBX: 1ffff1003b3eef99 RCX: 0000000000000000 RDX: 1ffffffff0d19078 RSI: 0000000000000001 RDI: ffffffff868c83c0 RBP: ffff8801d9f77cb0 R08: ffffffff86662ae8 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000001 R13: ffff8801d9f77d68 R14: ffffffff8702ffa0 R15: 0000000000000000 arch_safe_halt arch/x86/include/asm/paravirt.h:93 [inline] default_idle+0xbf/0x460 arch/x86/kernel/process.c:355 arch_cpu_idle+0xa/0x10 arch/x86/kernel/process.c:346 default_idle_call+0x36/0x90 kernel/sched/idle.c:98 cpuidle_idle_call kernel/sched/idle.c:156 [inline] do_idle+0x24a/0x3b0 kernel/sched/idle.c:246 cpu_startup_entry+0x104/0x120 kernel/sched/idle.c:351 start_secondary+0x40a/0x590 arch/x86/kernel/smpboot.c:268 secondary_startup_64+0xa5/0xb0 arch/x86/kernel/head_64.S:237 Code: f2 f2 f2 f2 c7 40 14 00 f2 f2 f2 c7 40 18 f2 f2 f2 f2 c7 40 1c 00 f2 f2 f2 c7 40 20 f3 f3 f3 f3 48 89 f8 48 c1 e8 03 80 3c 10 00 <0f> 85 68 05 00 00 4c 8b 25 61 ea e5 00 48 b8 00 00 00 00 00 fc