kworker/dying (4793) used greatest stack depth: 15376 bytes left INFO: task syz-executor4:19467 blocked for more than 120 seconds. Not tainted 4.15.0-rc9+ #9 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor4 D24272 19467 18741 0x80000004 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 __rwsem_down_read_failed_common kernel/locking/rwsem-xadd.c:269 [inline] rwsem_down_read_failed+0x401/0x6e0 kernel/locking/rwsem-xadd.c:286 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+0xa4/0x150 kernel/locking/rwsem.c:26 exit_mm kernel/exit.c:510 [inline] do_exit+0x4b0/0x1ad0 kernel/exit.c:852 do_group_exit+0x149/0x400 kernel/exit.c:968 get_signal+0x73f/0x16c0 kernel/signal.c:2335 do_signal+0x90/0x1eb0 arch/x86/kernel/signal.c:809 exit_to_usermode_loop+0x214/0x310 arch/x86/entry/common.c:158 prepare_exit_to_usermode arch/x86/entry/common.c:195 [inline] syscall_return_slowpath+0x490/0x550 arch/x86/entry/common.c:264 entry_SYSCALL_64_fastpath+0x9e/0xa0 RIP: 0033:0x4532ea RSP: 002b:00007ffec15e5448 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: fffffffffffffffc RBX: 0000000000000003 RCX: 00000000004532ea RDX: 0000000000000003 RSI: 0000000000021000 RDI: 0000000000000000 RBP: ffffffffffffffff R08: ffffffffffffffff R09: 0000000000000000 R10: 0000000000020022 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000021000 R14: 0000000000020022 R15: 0000000000000000 Showing all locks held in the system: 2 locks held by khungtaskd/760: #0: (rcu_read_lock){....}, at: [<0000000075503a76>] check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline] #0: (rcu_read_lock){....}, at: [<0000000075503a76>] watchdog+0x1c5/0xd60 kernel/hung_task.c:249 #1: (tasklist_lock){.+.+}, at: [<00000000b87f29d9>] debug_show_all_locks+0xd3/0x400 kernel/locking/lockdep.c:4464 1 lock held by khugepaged/766: #0: (&mm->mmap_sem){++++}, at: [<0000000040a20b56>] khugepaged_scan_mm_slot mm/khugepaged.c:1677 [inline] #0: (&mm->mmap_sem){++++}, at: [<0000000040a20b56>] khugepaged_do_scan mm/khugepaged.c:1810 [inline] #0: (&mm->mmap_sem){++++}, at: [<0000000040a20b56>] khugepaged+0x9d8/0x1400 mm/khugepaged.c:1855 1 lock held by rsyslogd/4008: #0: (&f->f_pos_lock){+.+.}, at: [<00000000f064ed5c>] __fdget_pos+0x12b/0x190 fs/file.c:770 2 locks held by getty/4130: #0: (&tty->ldisc_sem){++++}, at: [<00000000b7f26fec>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<000000009ac3c4b9>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131 2 locks held by getty/4131: #0: (&tty->ldisc_sem){++++}, at: [<00000000b7f26fec>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<000000009ac3c4b9>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131 2 locks held by getty/4132: #0: (&tty->ldisc_sem){++++}, at: [<00000000b7f26fec>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<000000009ac3c4b9>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131 2 locks held by getty/4133: #0: (&tty->ldisc_sem){++++}, at: [<00000000b7f26fec>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<000000009ac3c4b9>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131 2 locks held by getty/4134: #0: (&tty->ldisc_sem){++++}, at: [<00000000b7f26fec>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<000000009ac3c4b9>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131 2 locks held by getty/4135: #0: (&tty->ldisc_sem){++++}, at: [<00000000b7f26fec>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<000000009ac3c4b9>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131 2 locks held by getty/4136: #0: (&tty->ldisc_sem){++++}, at: [<00000000b7f26fec>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<000000009ac3c4b9>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131 1 lock held by syz-executor4/19467: #0: (&mm->mmap_sem){++++}, at: [<00000000c497fb24>] exit_mm kernel/exit.c:510 [inline] #0: (&mm->mmap_sem){++++}, at: [<00000000c497fb24>] do_exit+0x4b0/0x1ad0 kernel/exit.c:852 1 lock held by syz-executor4/19468: #0: (&mm->mmap_sem){++++}, at: [<00000000c497fb24>] exit_mm kernel/exit.c:510 [inline] #0: (&mm->mmap_sem){++++}, at: [<00000000c497fb24>] do_exit+0x4b0/0x1ad0 kernel/exit.c:852 1 lock held by syz-executor4/19469: #0: (&mm->mmap_sem){++++}, at: [<00000000c497fb24>] exit_mm kernel/exit.c:510 [inline] #0: (&mm->mmap_sem){++++}, at: [<00000000c497fb24>] do_exit+0x4b0/0x1ad0 kernel/exit.c:852 1 lock held by syz-executor4/19470: #0: (&mm->mmap_sem){++++}, at: [<00000000c497fb24>] exit_mm kernel/exit.c:510 [inline] #0: (&mm->mmap_sem){++++}, at: [<00000000c497fb24>] do_exit+0x4b0/0x1ad0 kernel/exit.c:852 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 760 Comm: khungtaskd Not tainted 4.15.0-rc9+ #9 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+0x3a/0x50 arch/x86/entry/entry_64.S:541 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 19471 Comm: syz-executor4 Not tainted 4.15.0-rc9+ #9 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__might_sleep+0x18/0x190 kernel/sched/core.c:6000 RSP: 0018:ffff8801ca6973b0 EFLAGS: 00000246 RAX: dffffc0000000000 RBX: ffff8801b6b32410 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 00000000000002eb RDI: ffffffff85eaadc0 RBP: ffff8801ca6973d0 R08: ffffffff81875792 R09: 0000000000000000 R10: ffff8801ca6977d8 R11: 0000000000000001 R12: ffffffff85eaadc0 R13: dffffc0000000000 R14: ffffffff81875792 R15: 0000000000000000 FS: 00007f532f11f700(0000) GS:ffff8801db400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000006fb45c CR3: 00000001b15f6006 CR4: 00000000001606f0 DR0: 0000000020000000 DR1: 0000000020000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 Call Trace: __mutex_lock_common kernel/locking/mutex.c:747 [inline] __mutex_lock+0x13e/0x1a80 kernel/locking/mutex.c:893 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908 perf_mmap+0x6b2/0x1b70 kernel/events/core.c:5280 call_mmap include/linux/fs.h:1777 [inline] mmap_region+0xa99/0x15a0 mm/mmap.c:1705 do_mmap+0x6c0/0xe00 mm/mmap.c:1483 do_mmap_pgoff include/linux/mm.h:2217 [inline] vm_mmap_pgoff+0x1de/0x280 mm/util.c:333 SYSC_mmap_pgoff mm/mmap.c:1533 [inline] SyS_mmap_pgoff+0x462/0x5f0 mm/mmap.c:1491 SYSC_mmap arch/x86/kernel/sys_x86_64.c:100 [inline] SyS_mmap+0x16/0x20 arch/x86/kernel/sys_x86_64.c:91 entry_SYSCALL_64_fastpath+0x29/0xa0 RIP: 0033:0x453299 RSP: 002b:00007f532f11ec58 EFLAGS: 00000212 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 00007f532f11f700 RCX: 0000000000453299 RDX: 0000000000000000 RSI: 0000000000002000 RDI: 0000000020007000 RBP: 00007ffec15e5570 R08: 0000000000000012 R09: 0000000000000000 R10: 0000000000000011 R11: 0000000000000212 R12: 0000000000000000 R13: 00007ffec15e54ef R14: 00007f532f11f9c0 R15: 0000000000000002 Code: 00 e9 1d fe ff ff e8 98 0b 5c 00 e9 f3 fd ff ff 0f 1f 00 55 48 b8 00 00 00 00 00 fc ff df 48 89 e5 41 56 41 55 41 54 49 89 fc 53 <65> 48 8b 1c 25 c0 ed 01 00 48 8d 7b 08 41 89 d6 48 83 ec 10 41