INFO: task syz-executor.0:7793 blocked for more than 143 seconds. Not tainted 5.1.0-rc5+ #77 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D27576 7793 7777 0x80000004 Call Trace: context_switch kernel/sched/core.c:2877 [inline] __schedule+0x813/0x1cc0 kernel/sched/core.c:3518 schedule+0x92/0x180 kernel/sched/core.c:3562 __rwsem_down_write_failed_common kernel/locking/rwsem-xadd.c:582 [inline] rwsem_down_write_failed+0x774/0xc30 kernel/locking/rwsem-xadd.c:611 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+0x53/0x90 kernel/locking/rwsem.c:72 lock_anon_vma_root mm/rmap.c:238 [inline] unlink_anon_vmas+0x184/0x870 mm/rmap.c:388 free_pgtables+0x1af/0x2f0 mm/memory.c:394 exit_mmap+0x2d1/0x530 mm/mmap.c:3144 __mmput kernel/fork.c:1046 [inline] mmput+0x15f/0x4c0 kernel/fork.c:1067 exit_mm kernel/exit.c:546 [inline] do_exit+0x816/0x2fa0 kernel/exit.c:863 do_group_exit+0x135/0x370 kernel/exit.c:980 get_signal+0x399/0x1d50 kernel/signal.c:2577 do_signal+0x87/0x1940 arch/x86/kernel/signal.c:816 exit_to_usermode_loop+0x244/0x2c0 arch/x86/entry/common.c:162 prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline] syscall_return_slowpath arch/x86/entry/common.c:268 [inline] do_syscall_64+0x52d/0x610 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x412c6a Code: 3a 44 00 31 c0 e8 e6 e3 00 00 e9 2e fe ff ff 90 48 89 d6 bf 69 37 44 00 31 c0 e8 d1 e3 00 00 e9 ba fd ff ff 0f 1f 40 00 48 8b c8 00 00 00 ff 15 db 6a 24 00 85 c0 89 c5 0f 85 0d fe ff ff e9 RSP: 002b:00007fff7f8e75c8 EFLAGS: 00000246 ORIG_RAX: 000000000000003d RAX: fffffffffffffe00 RBX: 0000000000001e72 RCX: 0000000000412c6a RDX: 0000000040000000 RSI: 00007fff7f8e75d4 RDI: ffffffffffffffff RBP: 00000000000000f8 R08: 0000000000001e71 R09: 0000000001726940 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000414930 R13: 00000000004149c0 R14: 0000000000000000 R15: 0000000000000000 Showing all locks held in the system: 3 locks held by kworker/u4:0/7: #0: 00000000a3a7a07d (&rq->lock){-.-.}, at: idle_balance kernel/sched/fair.c:10053 [inline] #0: 00000000a3a7a07d (&rq->lock){-.-.}, at: pick_next_task_fair+0x1214/0x19a0 kernel/sched/fair.c:7062 #1: 00000000cedeca72 (rcu_read_lock){....}, at: __update_idle_core+0x45/0x3f0 kernel/sched/fair.c:6059 #2: 000000004c010497 (&base->lock){-.-.}, at: lock_timer_base+0x56/0x1b0 kernel/time/timer.c:937 1 lock held by khungtaskd/1041: #0: 00000000cedeca72 (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x27e kernel/locking/lockdep.c:5056 2 locks held by getty/7758: #0: 000000002abd76bf (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000002eba1866 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7759: #0: 00000000fdd4def5 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000b1e2b20a (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7760: #0: 00000000be704a51 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000221f8410 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7761: #0: 000000003d0dc680 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 0000000058e06c28 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7762: #0: 00000000a10d0849 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000a9fd1bc7 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7763: #0: 000000009da989df (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000334e783f (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7764: #0: 000000009d2575df (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000b043b199 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 1 lock held by syz-executor.0/7793: #0: 00000000ea326232 (&anon_vma->rwsem){++++}, at: lock_anon_vma_root mm/rmap.c:238 [inline] #0: 00000000ea326232 (&anon_vma->rwsem){++++}, at: unlink_anon_vmas+0x184/0x870 mm/rmap.c:388 1 lock held by syz-executor.0/10388: ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1041 Comm: khungtaskd Not tainted 5.1.0-rc5+ #77 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: