kernel BUG at mm/hugetlb.c:LINE!

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit:    1a323ea5 x86: get rid of 'errret' argument to __get_user_x..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=132e940be00000
kernel config:  https://syzkaller.appspot.com/x/.config?x=8c1e98458335a7d1
dashboard link: https://syzkaller.appspot.com/bug?extid=d6ec23007e951dadf3de
compiler:       gcc (GCC) 9.0.0 20181231 (experimental)
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=12921933e00000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=172e940be00000

The bug was bisected to:

commit e950564b97fd0f541b02eb207685d0746f5ecf29
Author: Miklos Szeredi <mszeredi@xxxxxxxxxx>
Date:   Tue Jul 24 13:01:55 2018 +0000

    vfs: don't evict uninitialized inode

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=115cad33e00000
final crash:    https://syzkaller.appspot.com/x/report.txt?x=135cad33e00000
console output: https://syzkaller.appspot.com/x/log.txt?x=155cad33e00000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+d6ec23007e951dadf3de@xxxxxxxxxxxxxxxxxxxxxxxxx
Fixes: e950564b97fd ("vfs: don't evict uninitialized inode")

overlayfs: upper fs does not support xattr, falling back to index=off and metacopy=off.
------------[ cut here ]------------
kernel BUG at mm/hugetlb.c:3416!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 7036 Comm: syz-executor110 Not tainted 5.6.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:__unmap_hugepage_range+0xa26/0xbc0 mm/hugetlb.c:3416
Code: 00 48 c7 c7 60 37 35 88 e8 57 b4 a2 ff e9 b3 fd ff ff e8 cd 90 c6 ff 0f 0b e9 c4 f7 ff ff e8 c1 90 c6 ff 0f 0b e8 ba 90 c6 ff <0f> 0b e8 b3 90 c6 ff 83 8c 24 c0 00 00 00 01 48 8d bc 24 a0 00 00
RSP: 0018:ffffc900017779b0 EFLAGS: 00010293
RAX: ffff88808cf5c2c0 RBX: ffffffff8c641c08 RCX: ffffffff81ac50b4
RDX: 0000000000000000 RSI: ffffffff81ac58a6 RDI: 0000000000000007
RBP: 0000000020000000 R08: ffff88808cf5c2c0 R09: ffffed10129d8111
R10: ffffed10129d8110 R11: ffff888094ec0887 R12: 0000000000003000
R13: 0000000000000000 R14: 0000000020003000 R15: 0000000000200000
FS:  00000000013c0880(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020000140 CR3: 0000000093554000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 __unmap_hugepage_range_final+0x30/0x70 mm/hugetlb.c:3507
 unmap_single_vma+0x238/0x300 mm/memory.c:1296
 unmap_vmas+0x16f/0x2f0 mm/memory.c:1332
 exit_mmap+0x2aa/0x510 mm/mmap.c:3126
 __mmput kernel/fork.c:1082 [inline]
 mmput+0x168/0x4b0 kernel/fork.c:1103
 exit_mm kernel/exit.c:477 [inline]
 do_exit+0xa51/0x2dd0 kernel/exit.c:780
 do_group_exit+0x125/0x340 kernel/exit.c:891
 __do_sys_exit_group kernel/exit.c:902 [inline]
 __se_sys_exit_group kernel/exit.c:900 [inline]
 __x64_sys_exit_group+0x3a/0x50 kernel/exit.c:900
 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x49/0xb3
RIP: 0033:0x43efe8
Code: Bad RIP value.
RSP: 002b:00007ffdfe6c00f8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000043efe8
RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000
RBP: 00000000004be7e8 R08: 00000000000000e7 R09: ffffffffffffffd0
R10: 0000040000000011 R11: 0000000000000246 R12: 0000000000000001
R13: 00000000006d0180 R14: 0000000000000000 R15: 0000000000000000
Modules linked in:
---[ end trace 2d36245d65cb52f7 ]---
RIP: 0010:__unmap_hugepage_range+0xa26/0xbc0 mm/hugetlb.c:3416
Code: 00 48 c7 c7 60 37 35 88 e8 57 b4 a2 ff e9 b3 fd ff ff e8 cd 90 c6 ff 0f 0b e9 c4 f7 ff ff e8 c1 90 c6 ff 0f 0b e8 ba 90 c6 ff <0f> 0b e8 b3 90 c6 ff 83 8c 24 c0 00 00 00 01 48 8d bc 24 a0 00 00
RSP: 0018:ffffc900017779b0 EFLAGS: 00010293
RAX: ffff88808cf5c2c0 RBX: ffffffff8c641c08 RCX: ffffffff81ac50b4
RDX: 0000000000000000 RSI: ffffffff81ac58a6 RDI: 0000000000000007
RBP: 0000000020000000 R08: ffff88808cf5c2c0 R09: ffffed10129d8111
R10: ffffed10129d8110 R11: ffff888094ec0887 R12: 0000000000003000
R13: 0000000000000000 R14: 0000000020003000 R15: 0000000000200000
FS:  00000000013c0880(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f8cc24dd000 CR3: 0000000093554000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400


---
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