INFO: task syz-executor.2:9101 blocked for more than 143 seconds. Not tainted 5.2.0-rc4 #25 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.2 D27408 9101 9092 0x80004004 Call Trace: context_switch kernel/sched/core.c:2818 [inline] __schedule+0x7cb/0x1560 kernel/sched/core.c:3445 schedule+0xa8/0x260 kernel/sched/core.c:3509 __rwsem_down_write_failed_common kernel/locking/rwsem-xadd.c:601 [inline] rwsem_down_write_failed+0x7a1/0xc60 kernel/locking/rwsem-xadd.c:633 __down_write kernel/locking/rwsem.h:227 [inline] down_write+0x93/0xa0 kernel/locking/rwsem.c:68 lock_anon_vma_root mm/rmap.c:238 [inline] unlink_anon_vmas+0x184/0x870 mm/rmap.c:388 free_pgtables+0xe6/0x2f0 mm/memory.c:381 exit_mmap+0x2bc/0x510 mm/mmap.c:3146 __mmput kernel/fork.c:1059 [inline] mmput+0x15f/0x4c0 kernel/fork.c:1080 exit_mm kernel/exit.c:547 [inline] do_exit+0x816/0x2fa0 kernel/exit.c:864 do_group_exit+0x135/0x370 kernel/exit.c:981 get_signal+0x471/0x24b0 kernel/signal.c:2640 do_signal+0x87/0x1900 arch/x86/kernel/signal.c:815 exit_to_usermode_loop+0x244/0x2c0 arch/x86/entry/common.c:164 prepare_exit_to_usermode arch/x86/entry/common.c:199 [inline] syscall_return_slowpath arch/x86/entry/common.c:279 [inline] do_syscall_64+0x58e/0x680 arch/x86/entry/common.c:304 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x41320a Code: 86 cd 00 00 00 48 89 d3 31 d2 48 f7 f3 48 c7 41 30 00 00 00 00 48 c7 41 40 ff ff ff ff 48 89 41 38 48 c7 41 48 00 00 00 00 48 41 50 00 00 00 00 48 8b 41 38 48 89 04 24 e8 82 16 01 00 48 8b RSP: 002b:00007fffaece57b8 EFLAGS: 00000246 ORIG_RAX: 000000000000003d RAX: fffffffffffffe00 RBX: 000000000000238e RCX: 000000000041320a RDX: 0000000040000000 RSI: 00007fffaece57c4 RDI: ffffffffffffffff RBP: 00000000000000f8 R08: 000000000000238d R09: 0000555556044940 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000075c9a8 R13: 00007fffaece5a48 R14: 0000000000000000 R15: 0000000000000000 Showing all locks held in the system: 1 lock held by khungtaskd/1043: #0: 0000000072f26752 (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x27e kernel/locking/lockdep.c:5149 2 locks held by getty/9054: #0: 00000000f68d499b (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000005f74cb3b (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/9055: #0: 000000008378da72 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 0000000055c9b300 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/9056: #0: 00000000a3e3e128 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000004cf1a984 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/9057: #0: 00000000c3adc4f5 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000433b6b8d (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/9058: #0: 0000000039cab31c (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000c1218f6e (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/9059: #0: 000000009189e419 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 0000000089127836 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/9060: #0: 000000005450d957 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000147a8d59 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 1 lock held by syz-executor.2/9101: #0: 00000000c5bff859 (&anon_vma->rwsem){++++}, at: lock_anon_vma_root mm/rmap.c:238 [inline] #0: 00000000c5bff859 (&anon_vma->rwsem){++++}, at: unlink_anon_vmas+0x184/0x870 mm/rmap.c:388 1 lock held by syz-executor.2/17795: ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1043 Comm: khungtaskd Not tainted 5.2.0-rc4 #25 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:205 [inline] watchdog+0x9b7/0xec0 kernel/hung_task.c:289 kthread+0x354/0x420 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 skipped: idling at native_safe_halt+0xe/0x10 arch/x86/include/asm/irqflags.h:60