INFO: task syz-executor.4:6164 blocked for more than 143 seconds. Not tainted 5.0.0+ #21 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.4 D28368 6164 12381 0x00000004 Call Trace: context_switch kernel/sched/core.c:2877 [inline] __schedule+0x817/0x1cc0 kernel/sched/core.c:3518 schedule+0x92/0x180 kernel/sched/core.c:3562 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3620 __mutex_lock_common kernel/locking/mutex.c:1002 [inline] __mutex_lock+0x726/0x1310 kernel/locking/mutex.c:1072 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087 blk_trace_setup+0x3b/0x70 kernel/trace/blktrace.c:594 sg_ioctl+0x369/0x2a10 drivers/scsi/sg.c:1117 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:509 [inline] do_vfs_ioctl+0xd6e/0x1390 fs/ioctl.c:696 ksys_ioctl+0xab/0xd0 fs/ioctl.c:713 __do_sys_ioctl fs/ioctl.c:720 [inline] __se_sys_ioctl fs/ioctl.c:718 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:718 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x458079 Code: Bad RIP value. RSP: 002b:00007f3f7fe9ac78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000458079 RDX: 0000000020000000 RSI: 00000000c0481273 RDI: 0000000000000005 RBP: 000000000073bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f3f7fe9b6d4 R13: 00000000004bf471 R14: 00000000004d0eb0 R15: 00000000ffffffff Showing all locks held in the system: 1 lock held by init/1: #0: 0000000023bbb0ba (&ei->i_mmap_sem){++++}, at: ext4_filemap_fault+0x7b/0xaf fs/ext4/inode.c:6308 1 lock held by khungtaskd/1039: #0: 0000000051826688 (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x27e kernel/locking/lockdep.c:5061 3 locks held by udevd/3874: 1 lock held by rsyslogd/7829: #0: 000000008b69195e (&ei->i_mmap_sem){++++}, at: ext4_filemap_fault+0x7b/0xaf fs/ext4/inode.c:6308 1 lock held by cron/7868: #0: 000000008b69195e (&ei->i_mmap_sem){++++}, at: ext4_filemap_fault+0x7b/0xaf fs/ext4/inode.c:6308 2 locks held by getty/7918: #0: 00000000f97b7fc4 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000002b6cae71 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7919: #0: 000000001cbb704d (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000d6f9b344 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7920: #0: 0000000042522f8c (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000c8551e67 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7921: #0: 0000000063879fe9 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000001505bf66 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7922: #0: 0000000097a4eb87 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 0000000045d34bf0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7923: #0: 00000000ad09c629 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000cf8430aa (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7924: #0: 00000000f6d232fa (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000775cd4b1 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 1 lock held by syz-fuzzer/7938: #0: 0000000093f5e00b (&ei->i_mmap_sem){++++}, at: ext4_filemap_fault+0x7b/0xaf fs/ext4/inode.c:6308 1 lock held by syz-fuzzer/7949: #0: 0000000093f5e00b (&ei->i_mmap_sem){++++}, at: ext4_filemap_fault+0x7b/0xaf fs/ext4/inode.c:6308 1 lock held by syz-executor.2/7960: #0: 00000000f3cdf467 (&ei->i_mmap_sem){++++}, at: ext4_filemap_fault+0x7b/0xaf fs/ext4/inode.c:6308 1 lock held by syz-executor.4/12381: #0: 00000000f3cdf467 (&ei->i_mmap_sem){++++}, at: ext4_filemap_fault+0x7b/0xaf fs/ext4/inode.c:6308 2 locks held by syz-executor.2/5989: 1 lock held by syz-executor.4/6164: #0: 00000000d8347b0d (&q->blk_trace_mutex){+.+.}, at: blk_trace_setup+0x3b/0x70 kernel/trace/blktrace.c:594 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1039 Comm: khungtaskd Not tainted 5.0.0+ #21 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+0x172/0x1f0 lib/dump_stack.c:113 nmi_cpu_backtrace.cold+0x63/0xa4 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1be/0x236 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:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:204 [inline] watchdog+0x9b7/0xec0 kernel/hung_task.c:288 kthread+0x357/0x430 kernel/kthread.c:253 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 Sending NMI from CPU 0 to CPUs 1: