syzbot

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WARNING: CPU: 0 PID: 2883 at mm/gup.c:388 check_vma_flags mm/gup.c:388 [inline]()
WARNING: CPU: 0 PID: 2883 at mm/gup.c:388 __get_user_pages+0xae7/0xfd0 mm/gup.c:502()
Kernel panic - not syncing: panic_on_warn set ...

CPU: 0 PID: 2883 Comm: syz-executor551 Not tainted 4.4.174+ #4
 0000000000000000 e74ea12659d4ff13 ffff8801d1dcf890 ffffffff81aad1a1
 0000000000000000 ffffffff82835ee0 ffffffff82892ea0 0000000000000184
 ffffffff8142cb27 ffff8801d1dcf970 ffffffff813a48c2 0000000041b58ab3
Call Trace:
 [<ffffffff81aad1a1>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81aad1a1>] dump_stack+0xc1/0x120 lib/dump_stack.c:51
 [<ffffffff813a48c2>] panic+0x1b9/0x37b kernel/panic.c:112
 [<ffffffff813a4ab9>] warn_slowpath_common kernel/panic.c:455 [inline]
 [<ffffffff813a4ab9>] warn_slowpath_common.cold+0x20/0x20 kernel/panic.c:435
 [<ffffffff810d3aaa>] warn_slowpath_null+0x2a/0x30 kernel/panic.c:492
 [<ffffffff8142cb27>] check_vma_flags mm/gup.c:388 [inline]
 [<ffffffff8142cb27>] __get_user_pages+0xae7/0xfd0 mm/gup.c:502
 [<ffffffff8142d73d>] __get_user_pages_locked mm/gup.c:654 [inline]
 [<ffffffff8142d73d>] get_user_pages+0x6d/0x90 mm/gup.c:864
 [<ffffffff8142eef3>] __access_remote_vm+0x1e3/0x3c0 mm/memory.c:3727
 [<ffffffff81435a16>] access_remote_vm+0x36/0x50 mm/memory.c:3787
 [<ffffffff815eaf68>] mem_rw.isra.0+0x178/0x320 fs/proc/base.c:898
 [<ffffffff815eb165>] mem_write+0x55/0x70 fs/proc/base.c:932
 [<ffffffff81496916>] __vfs_write+0x116/0x3d0 fs/read_write.c:491
 [<ffffffff81498612>] vfs_write+0x182/0x4e0 fs/read_write.c:540
 [<ffffffff8149ac4c>] SYSC_write fs/read_write.c:587 [inline]
 [<ffffffff8149ac4c>] SyS_write+0xdc/0x1c0 fs/read_write.c:579
 [<ffffffff82718ba1>] entry_SYSCALL_64_fastpath+0x1e/0x9a
Kernel Offset: disabled
Rebooting in 86400 seconds..