INFO: task syz-executor.1:18499 blocked for more than 143 seconds. Not tainted 5.1.0-rc3+ #48 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.1 D29880 18499 7818 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 __rwsem_down_read_failed_common kernel/locking/rwsem-xadd.c:285 [inline] rwsem_down_read_failed+0x213/0x420 kernel/locking/rwsem-xadd.c:302 call_rwsem_down_read_failed+0x18/0x30 arch/x86/lib/rwsem.S:94 __down_read arch/x86/include/asm/rwsem.h:83 [inline] down_read+0x49/0x90 kernel/locking/rwsem.c:26 __get_super.part.0+0x203/0x2e0 fs/super.c:788 __get_super include/linux/spinlock.h:329 [inline] __get_super_thawed+0x13a/0x2d0 fs/super.c:825 get_super_thawed+0x18/0x20 fs/super.c:849 quotactl_block fs/quota/quota.c:818 [inline] kernel_quotactl+0x1e8/0x1540 fs/quota/quota.c:872 __do_sys_quotactl fs/quota/quota.c:893 [inline] __se_sys_quotactl fs/quota/quota.c:890 [inline] __x64_sys_quotactl+0x97/0xf0 fs/quota/quota.c:890 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x4582b9 Code: Bad RIP value. RSP: 002b:00007fe259bf4c78 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3 RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 00000000004582b9 RDX: 0000000000000000 RSI: 0000000020000140 RDI: 0000000000000000 RBP: 000000000073bfa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fe259bf56d4 R13: 00000000004c4e92 R14: 00000000004d8c90 R15: 00000000ffffffff Showing all locks held in the system: 1 lock held by khungtaskd/1042: #0: 000000006a55786e (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x27e kernel/locking/lockdep.c:5061 1 lock held by rsyslogd/7667: #0: 00000000ba3e46c6 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:801 2 locks held by getty/7779: #0: 00000000623c13d4 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000cb469d88 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7780: #0: 00000000a2ddb63b (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000f4573b34 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7781: #0: 0000000004c21d5e (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000110a5d89 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7782: #0: 000000008ff8486e (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000ce3a1e83 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7783: #0: 00000000dce2d186 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000001583c096 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7784: #0: 000000004d3d87bf (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000005e2ab709 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7785: #0: 00000000afc202ed (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000a4710f82 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by syz-executor.1/18489: 1 lock held by syz-executor.1/18499: #0: 00000000a7e4f213 (&type->s_umount_key#68){.+.+}, at: __get_super.part.0+0x203/0x2e0 fs/super.c:788 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1042 Comm: khungtaskd Not tainted 5.1.0-rc3+ #48 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: