Node 0 DMA: 9*4kB (U) 7*8kB (UM) 1*16kB (M) 0*32kB 1*64kB (U) 1*128kB (M) 2*256kB (UM) 2*512kB (UM) 1*1024kB (M) 2*2048kB (M) 1*4096kB (M) = 11052kB
Node 0 DMA32: 1180*4kB (MEH) 534*8kB (UMEH) 265*16kB (UMEH) 129*32kB (UMEH) 77*64kB (UMEH) 44*128kB (UMEH) 16*256kB (UMH) 4*512kB (UM) 2*1024kB (MH) 0*2048kB 0*4096kB = 36112kB
INFO: task syz-executor.1:7970 blocked for more than 140 seconds.
      Not tainted 4.14.262-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.1  D24824  7970   7964 0x00000000
Node 0 Normal: 0*4kB 0*8kB 0*16kB 0*32kB 0*64kB 0*128kB 0*256kB 0*512kB 0*1024kB 0*2048kB 0*4096kB = 0kB
Call Trace:
 context_switch kernel/sched/core.c:2811 [inline]
 __schedule+0x88b/0x1de0 kernel/sched/core.c:3387
Node 1 
 schedule+0x8d/0x1b0 kernel/sched/core.c:3431
 __rwsem_down_write_failed_common kernel/locking/rwsem-xadd.c:588 [inline]
 rwsem_down_write_failed+0x343/0x6d0 kernel/locking/rwsem-xadd.c:617
Normal: 
 call_rwsem_down_write_failed+0x13/0x20 arch/x86/lib/rwsem.S:105
6*4kB (UME) 6*8kB (UM) 4*16kB (UM) 3*32kB (UE) 2*64kB (UM) 3*128kB (ME) 4*256kB (UM) 2*512kB (M) 3*1024kB (UME) 1*2048kB (M) 11*4096kB (M) = 52968kB
 __down_write arch/x86/include/asm/rwsem.h:126 [inline]
 down_write+0x4f/0x90 kernel/locking/rwsem.c:56
 namespace_lock fs/namespace.c:1455 [inline]
 do_umount fs/namespace.c:1626 [inline]
 SYSC_umount fs/namespace.c:1754 [inline]
 SyS_umount+0x625/0xeb0 fs/namespace.c:1723
Node 0 hugepages_total=0 hugepages_free=0 hugepages_surp=0 hugepages_size=1048576kB
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x7f26dd223457
RSP: 002b:00007fff16397c38 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f26dd223457
RDX: 00007fff16397d09 RSI: 000000000000000a RDI: 00007fff16397d00
RBP: 00007fff16397d00 R08: 00000000ffffffff R09: 00007fff16397ad0
R10: 0000555555dcd91b R11: 0000000000000246 R12: 00007f26dd27b1ea
R13: 00007fff16398dc0 R14: 0000555555dcd810 R15: 00007fff16398e00
INFO: task syz-executor.5:9514 blocked for more than 140 seconds.
      Not tainted 4.14.262-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.5  D28976  9514   7966 0x00000000