INFO: task syz-executor1:31523 blocked for more than 120 seconds. Not tainted 4.15.0-rc8+ #8 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor1 D23120 31523 31305 0x80000000 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 SYSC_exit_group kernel/exit.c:979 [inline] SyS_exit_group+0x1d/0x20 kernel/exit.c:977 entry_SYSCALL_64_fastpath+0x29/0xa0 RIP: 0033:0x453299 RSP: 002b:00007ffe8b8eb438 EFLAGS: 00000202 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 00007f55944bc700 RCX: 0000000000453299 RDX: 0000000000000001 RSI: 00000000007214f8 RDI: 0000000000000000 RBP: 00007ffe8b8eb280 R08: 0000000000000000 R09: 00000000006fb968 R10: 000000000071c010 R11: 0000000000000202 R12: 0000000000000000 R13: 00007ffe8b8eb1ff R14: 00007f55944bc9c0 R15: 0000000000000008 Showing all locks held in the system: 2 locks held by khungtaskd/760: #0: (rcu_read_lock){....}, at: [<000000004f04fff0>] check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline] #0: (rcu_read_lock){....}, at: [<000000004f04fff0>] watchdog+0x1c5/0xd60 kernel/hung_task.c:249 #1: (tasklist_lock){.+.+}, at: [<000000001fe0c4eb>] debug_show_all_locks+0xd3/0x400 kernel/locking/lockdep.c:4464 1 lock held by khugepaged/766: #0: (&mm->mmap_sem){++++}, at: [<000000005d3236a6>] khugepaged_scan_mm_slot mm/khugepaged.c:1677 [inline] #0: (&mm->mmap_sem){++++}, at: [<000000005d3236a6>] khugepaged_do_scan mm/khugepaged.c:1810 [inline] #0: (&mm->mmap_sem){++++}, at: [<000000005d3236a6>] khugepaged+0x9d8/0x1400 mm/khugepaged.c:1855 1 lock held by rsyslogd/3531: #0: (&f->f_pos_lock){+.+.}, at: [<0000000028aa3c97>] __fdget_pos+0x12b/0x190 fs/file.c:770 2 locks held by getty/3653: #0: (&tty->ldisc_sem){++++}, at: [<0000000052a0e5be>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000d60387f0>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131 2 locks held by getty/3654: #0: (&tty->ldisc_sem){++++}, at: [<0000000052a0e5be>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000d60387f0>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131 2 locks held by getty/3655: #0: (&tty->ldisc_sem){++++}, at: [<0000000052a0e5be>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000d60387f0>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131 2 locks held by getty/3656: #0: (&tty->ldisc_sem){++++}, at: [<0000000052a0e5be>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000d60387f0>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131 2 locks held by getty/3657: #0: (&tty->ldisc_sem){++++}, at: [<0000000052a0e5be>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000d60387f0>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131 2 locks held by getty/3658: #0: (&tty->ldisc_sem){++++}, at: [<0000000052a0e5be>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000d60387f0>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131 2 locks held by getty/3659: #0: (&tty->ldisc_sem){++++}, at: [<0000000052a0e5be>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000d60387f0>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131 1 lock held by syz-executor1/31523: #0: (&mm->mmap_sem){++++}, at: [<000000001c09ebc1>] exit_mm kernel/exit.c:510 [inline] #0: (&mm->mmap_sem){++++}, at: [<000000001c09ebc1>] do_exit+0x4b0/0x1ad0 kernel/exit.c:852 1 lock held by syz-executor1/31533: #0: (&mm->mmap_sem){++++}, at: [<000000001c09ebc1>] exit_mm kernel/exit.c:510 [inline] #0: (&mm->mmap_sem){++++}, at: [<000000001c09ebc1>] do_exit+0x4b0/0x1ad0 kernel/exit.c:852 1 lock held by syz-executor1/31539: #0: (&mm->mmap_sem){++++}, at: [<000000001c09ebc1>] exit_mm kernel/exit.c:510 [inline] #0: (&mm->mmap_sem){++++}, at: [<000000001c09ebc1>] do_exit+0x4b0/0x1ad0 kernel/exit.c:852 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 760 Comm: khungtaskd Not tainted 4.15.0-rc8+ #8 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: 31527 Comm: syz-executor1 Not tainted 4.15.0-rc8+ #8 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:atomic_inc arch/x86/include/asm/atomic.h:92 [inline] RIP: 0010:__lock_acquire+0x210/0x3e00 kernel/locking/lockdep.c:3318 RSP: 0018:ffff8801b2feef00 EFLAGS: 00000002 RAX: ffffffff87cc09a0 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 1ffff1003858486f RSI: 0000000000000000 RDI: ffff8801c2c24378 RBP: ffff8801b2fef290 R08: ffffffff818756c2 R09: 0000000000000000 R10: 0000000000000000 R11: ffff8801c2c24370 R12: 0000000000000000 R13: 0000000000000001 R14: 0000000000000000 R15: ffff8801af6c0040 FS: 00007f55944fe700(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000006fb45c CR3: 00000001bdbbb004 CR4: 00000000001606f0 DR0: 0000000020000000 DR1: 0000000020000000 DR2: 0000000020000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 Call Trace: lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:3914 __mutex_lock_common kernel/locking/mutex.c:756 [inline] __mutex_lock+0x16f/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:00007f55944fdc58 EFLAGS: 00000212 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 000000000071bea0 RCX: 0000000000453299 RDX: 0000000000000000 RSI: 0000000000002000 RDI: 0000000020006000 RBP: 0000000000000431 R08: 0000000000000014 R09: 0000000000000000 R10: 0000000000000011 R11: 0000000000000212 R12: 00000000006f5538 R13: 00000000ffffffff R14: 00007f55944fe6d4 R15: 0000000000000000 Code: fc ff ff 8b 8d e0 fc ff ff 44 8b 8d d8 fc ff ff 4c 8b 85 d0 fc ff ff 44 8b 95 c8 fc ff ff 0f 84 9b 07 00 00 f0 ff 80 38 01 00 00 <49> 8d bf 70 08 00 00 48 ba 00 00 00 00 00 fc ff df 48 89 fe 48