[syzbot] BUG: sleeping function called from invalid context in copy_huge_page

[syzbot <syzbot+aae069be1de40fb11825@syzkaller.appspotmail.com>]

Hello,

syzbot found the following issue on:

HEAD commit:    1da38549dd64 Merge tag 'nfsd-5.15-3' of git://git.kernel.o..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=14379148b00000
kernel config:  https://syzkaller.appspot.com/x/.config?x=76f7496a8217e5ec
dashboard link: https://syzkaller.appspot.com/bug?extid=aae069be1de40fb11825
compiler:       gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2

Unfortunately, I don't have any reproducer for this issue yet.

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+aae069be1de40fb11825@syzkaller.appspotmail.com

BUG: sleeping function called from invalid context at mm/util.c:758
in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 30700, name: syz-executor.2
2 locks held by syz-executor.2/30700:
 #0: ffff88806ee498a8 (&mm->mmap_lock#2){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:71 [inline]
 #0: ffff88806ee498a8 (&mm->mmap_lock#2){++++}-{3:3}, at: do_mbind+0x25d/0xeb0 mm/mempolicy.c:1314
 #1: ffff888145989e18 (&mapping->private_lock){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:363 [inline]
 #1: ffff888145989e18 (&mapping->private_lock){+.+.}-{2:2}, at: __buffer_migrate_page+0x3af/0xca0 mm/migrate.c:723
Preemption disabled at:
[<0000000000000000>] 0x0
CPU: 1 PID: 30700 Comm: syz-executor.2 Not tainted 5.15.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
 ___might_sleep.cold+0x1f3/0x239 kernel/sched/core.c:9538
 copy_huge_page+0x126/0x360 mm/util.c:758
 migrate_page_copy+0xfc/0x340 mm/migrate.c:619
 __buffer_migrate_page+0x8cb/0xca0 mm/migrate.c:758
 move_to_new_page+0x339/0xef0 mm/migrate.c:905
 __unmap_and_move mm/migrate.c:1070 [inline]
 unmap_and_move mm/migrate.c:1211 [inline]
 migrate_pages+0xfc5/0x39e0 mm/migrate.c:1488
 do_mbind+0xbc7/0xeb0 mm/mempolicy.c:1340
 kernel_mbind mm/mempolicy.c:1483 [inline]
 __do_sys_mbind mm/mempolicy.c:1490 [inline]
 __se_sys_mbind mm/mempolicy.c:1486 [inline]
 __x64_sys_mbind+0x233/0x2b0 mm/mempolicy.c:1486
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f408623f8d9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f40837b6188 EFLAGS: 00000246 ORIG_RAX: 00000000000000ed
RAX: ffffffffffffffda RBX: 00007f4086343f60 RCX: 00007f408623f8d9
RDX: 0000000000000000 RSI: 0000000000c00000 RDI: 0000000020012000
RBP: 00007f4086299cb4 R08: 0000000000000000 R09: 0000010000000002
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fff13d3589f R14: 00007f40837b6300 R15: 0000000000022000


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