mainline inclusion
from mainline-5.9-rc1
commit 51a4cc11
category: feature
bugzilla: https://bugzilla.openeuler.org/show_bug.cgi?id=27
CVE: NA
---------------------------

If we're in the error path failing links and we have a link that has
grabbed a reference to the fs_struct, then we cannot safely drop our
reference to the table if we already hold the completion lock. This
adds a hardirq dependency to the fs_struct->lock, which it currently
doesn't have.

Defer the final cleanup and free of such requests to avoid adding this
dependency.

Reported-by: syzbot+ef4b654b49ed7ff049bf@syzkaller.appspotmail.com
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Conflicts:
	fs/io_uring.c
[adopt patch ecfc5177 ("io_uring: fix potential use after free on
fallback request free") lead this conflict]
Signed-off-by: Nyangerkun <yangerkun@huawei.com>
Reviewed-by: Nzhangyi (F) <yi.zhang@huawei.com>
Signed-off-by: NCheng Jian <cj.chengjian@huawei.com>