INFO: task syz-executor.4:30126 blocked for more than 140 seconds.
      Not tainted 4.14.111+ #54
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.4  D28808 30126   1961 0x80000000
Call Trace:
 schedule+0x92/0x1c0 kernel/sched/core.c:3498
 __rwsem_down_read_failed_common kernel/locking/rwsem-xadd.c:276 [inline]
 rwsem_down_read_failed+0x21f/0x3c0 kernel/locking/rwsem-xadd.c:293
 call_rwsem_down_read_failed+0x14/0x30 arch/x86/lib/rwsem.S:94
 __down_read arch/x86/include/asm/rwsem.h:66 [inline]
 down_read+0x45/0xa0 kernel/locking/rwsem.c:26
 exit_mm kernel/exit.c:511 [inline]
 do_exit+0x503/0x2960 kernel/exit.c:861
INFO: task syz-executor.4:30127 blocked for more than 140 seconds.
      Not tainted 4.14.111+ #54
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.4  D28280 30127   1961 0x80000000
Call Trace:
 schedule+0x92/0x1c0 kernel/sched/core.c:3498
 __rwsem_down_read_failed_common kernel/locking/rwsem-xadd.c:276 [inline]
 rwsem_down_read_failed+0x21f/0x3c0 kernel/locking/rwsem-xadd.c:293
 call_rwsem_down_read_failed+0x14/0x30 arch/x86/lib/rwsem.S:94
 __down_read arch/x86/include/asm/rwsem.h:66 [inline]
 down_read+0x45/0xa0 kernel/locking/rwsem.c:26
 exit_mm kernel/exit.c:511 [inline]
 do_exit+0x503/0x2960 kernel/exit.c:861

Showing all locks held in the system:
1 lock held by khungtaskd/23:
 #0:  (tasklist_lock){.+.+}, at: [<        (ptrval)>] debug_show_all_locks+0x7c/0x21a kernel/locking/lockdep.c:4544
2 locks held by getty/1750:
 #0:  (&tty->ldisc_sem){++++}, at: [<        (ptrval)>] tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:275
 #1:  (&ldata->atomic_read_lock){+.+.}, at: [<        (ptrval)>] n_tty_read+0x1f7/0x1700 drivers/tty/n_tty.c:2156
1 lock held by syz-executor.4/30126:
 #0:  (&mm->mmap_sem){++++}, at: [<        (ptrval)>] exit_mm kernel/exit.c:511 [inline]
 #0:  (&mm->mmap_sem){++++}, at: [<        (ptrval)>] do_exit+0x503/0x2960 kernel/exit.c:861
1 lock held by syz-executor.4/30127:
 #0:  (&mm->mmap_sem){++++}, at: [<        (ptrval)>] exit_mm kernel/exit.c:511 [inline]
 #0:  (&mm->mmap_sem){++++}, at: [<        (ptrval)>] do_exit+0x503/0x2960 kernel/exit.c:861

=============================================

NMI backtrace for cpu 1
CPU: 1 PID: 23 Comm: khungtaskd Not tainted 4.14.111+ #54
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0xb9/0x10e lib/dump_stack.c:53
 nmi_cpu_backtrace.cold+0x47/0x86 lib/nmi_backtrace.c:101
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 30131 Comm: syz-executor.4 Not tainted 4.14.111+ #54
task:         (ptrval) task.stack:         (ptrval)
RIP: 0010:__read_once_size include/linux/compiler.h:183 [inline]
RIP: 0010:atomic64_read arch/x86/include/asm/atomic64_64.h:22 [inline]
RIP: 0010:atomic_long_read include/asm-generic/atomic-long.h:45 [inline]
RIP: 0010:__mutex_unlock_slowpath+0xa5/0x7d0 kernel/locking/mutex.c:1027
RSP: 0018:ffff8881bcdafb90 EFLAGS: 00000246
RAX: 1ffff110385f438c RBX: dffffc0000000000 RCX: 1ffff11037f356e4
RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000000000246
RBP: ffff8881c2fa1c60 R08: 0000000000000001 R09: 0000000000000001
R10: ffff8881bcdafc68 R11: 0000000000000001 R12: 1ffff110379b5f76
R13: ffff8881d2a0e328 R14: ffff8881bcdafbd0 R15: 0000000000000000
FS:  00007ff63230e700(0000) GS:ffff8881d7400000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f68e1b8b000 CR3: 00000001c31d0003 CR4: 00000000001606b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 perf_mmap+0x637/0x1390 kernel/events/core.c:5429
 call_mmap include/linux/fs.h:1789 [inline]
 mmap_region+0x7c9/0xf00 mm/mmap.c:1731
 do_mmap+0x548/0xb80 mm/mmap.c:1509
 do_mmap_pgoff include/linux/mm.h:2167 [inline]
 vm_mmap_pgoff+0x177/0x1c0 mm/util.c:333
 SYSC_mmap_pgoff mm/mmap.c:1559 [inline]
 SyS_mmap_pgoff+0xf4/0x1b0 mm/mmap.c:1517
 do_syscall_64+0x19b/0x4b0 arch/x86/entry/common.c:289
Code: 00 00 31 c0 4c 89 74 24 48 48 c7 44 24 50 00 00 00 00 48 c7 44 24 40 01 00 00 00 e8 96 19 9c fe 48 89 e8 48 c1 e8 03 80 3c 18 00 <0f> 85 9e 05 00 00 49 c7 c5 e0 c5 a0 b5 48 8b 5d 00 49 b9 00 00