rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-...0: (1 GPs behind) idle=018c/1/0x40000002 softirq=168767/168768 fqs=5998
rcu: 	         hardirqs   softirqs   csw/system
rcu: 	 number:        0          0            0
rcu: 	cputime:        0          0            0   ==> 150000(ms)
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P25344/3:b..l
rcu: 	(detected by 1, t=30002 jiffies, g=346089, q=610 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
task:syz.0.5376      state:R  running task     stack:0     pid:25344 tgid:25337 ppid:23658  task_flags:0x400040 flags:0x00000005
Call trace: 
[<81a3d95c>] (__schedule) from [<81a3ea88>] (preempt_schedule_common kernel/sched/core.c:7145 [inline])
[<81a3d95c>] (__schedule) from [<81a3ea88>] (preempt_schedule+0x4c/0xb4 kernel/sched/core.c:7169)
 r10:00000003 r9:ec11dd88 r8:85f8d400 r7:8046b954 r6:00000001 r5:85ea3c00
 r4:81a47858
[<81a3ea3c>] (preempt_schedule) from [<81a47858>] (__raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline])
[<81a3ea3c>] (preempt_schedule) from [<81a47858>] (_raw_spin_unlock+0x4c/0x50 kernel/locking/spinlock.c:186)
 r7:85ea3c00 r6:0000024b r5:0000024b r4:85595380
[<81a4780c>] (_raw_spin_unlock) from [<8046b954>] (spin_unlock include/linux/spinlock.h:391 [inline])
[<81a4780c>] (_raw_spin_unlock) from [<8046b954>] (filemap_map_pages+0x4f4/0x694 mm/filemap.c:3791)
[<8046b460>] (filemap_map_pages) from [<804c75d0>] (do_fault_around mm/memory.c:5531 [inline])
[<8046b460>] (filemap_map_pages) from [<804c75d0>] (do_read_fault mm/memory.c:5564 [inline])
[<8046b460>] (filemap_map_pages) from [<804c75d0>] (do_fault mm/memory.c:5707 [inline])
[<8046b460>] (filemap_map_pages) from [<804c75d0>] (do_pte_missing mm/memory.c:4234 [inline])
[<8046b460>] (filemap_map_pages) from [<804c75d0>] (handle_pte_fault mm/memory.c:6052 [inline])
[<8046b460>] (filemap_map_pages) from [<804c75d0>] (__handle_mm_fault mm/memory.c:6195 [inline])
[<8046b460>] (filemap_map_pages) from [<804c75d0>] (handle_mm_fault+0xb98/0x14dc mm/memory.c:6364)
 r10:00000000 r9:00000040 r8:85595380 r7:00000000 r6:2024c000 r5:85ea3c00
 r4:00000014
[<804c6a38>] (handle_mm_fault) from [<804b8f84>] (faultin_page mm/gup.c:1144 [inline])
[<804c6a38>] (handle_mm_fault) from [<804b8f84>] (__get_user_pages+0x254/0x6f0 mm/gup.c:1446)
 r10:0000024c r9:2024c000 r8:85ea3c00 r7:00000000 r6:00000014 r5:85f8d400
 r4:00210008
[<804b8d30>] (__get_user_pages) from [<804bbc04>] (populate_vma_page_range+0xd8/0x220 mm/gup.c:1880)
 r10:20000000 r9:85595380 r8:ec11deb8 r7:20b36000 r6:20000000 r5:85f8d400
 r4:00000b36
[<804bbb2c>] (populate_vma_page_range) from [<804bc3e4>] (__mm_populate+0x11c/0x1b8 mm/gup.c:1983)
 r10:20000000 r9:85595404 r8:00000001 r7:85595380 r6:20b36000 r5:20b36000
 r4:85f8d400
[<804bc2c8>] (__mm_populate) from [<8049cca0>] (mm_populate include/linux/mm.h:3367 [inline])
[<804bc2c8>] (__mm_populate) from [<8049cca0>] (vm_mmap_pgoff+0x18c/0x204 mm/util.c:585)
 r10:85595380 r9:20000000 r8:00b36000 r7:ec11df18 r6:00000000 r5:06ebbeee
 r4:20000000
[<8049cb14>] (vm_mmap_pgoff) from [<804cec2c>] (ksys_mmap_pgoff+0x48/0xec mm/mmap.c:604)
 r10:000000c0 r9:85ea3c00 r8:8020029c r7:20000000 r6:00b36000 r5:06ebbeee
 r4:00008031
[<804cebe4>] (ksys_mmap_pgoff) from [<804cecec>] (__do_sys_mmap_pgoff mm/mmap.c:615 [inline])
[<804cebe4>] (ksys_mmap_pgoff) from [<804cecec>] (sys_mmap_pgoff+0x1c/0x24 mm/mmap.c:611)
 r8:8020029c r7:000000c0 r6:003063b4 r5:00000000 r4:ffffffff
[<804cecd0>] (sys_mmap_pgoff) from [<80200060>] (ret_fast_syscall+0x0/0x1c arch/arm/mm/proc-v7.S:67)
Exception stack(0xec11dfa8 to 0xec11dff0)
dfa0:                   ffffffff 00000000 20000000 00b36000 06ebbeee 00008031
dfc0: ffffffff 00000000 003063b4 000000c0 002f0000 00000000 00006364 76efa0bc
dfe0: 76ef9ec0 76ef9eb0 0001948c 001322a0