io_uring/fdinfo: lock SQ thread while retrieving thread cpu/pid

mainline inclusion
from mainline-v6.7
commit 7644b1a1
category: bugfix
bugzilla: 189322, https://gitee.com/src-openeuler/kernel/issues/I8BQSX
CVE: CVE-2023-46862

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=7644b1a1c9a7ae8ab99175989bfc8676055edb46

--------------------------------

We could race with SQ thread exit, and if we do, we'll hit a NULL pointer
dereference when the thread is cleared. Grab the SQPOLL data lock before
attempting to get the task cpu and pid for fdinfo, this ensures we have a
stable view of it.

Cc: stable@vger.kernel.org
Link: https://bugzilla.kernel.org/show_bug.cgi?id=218032


Reviewed-by: Gabriel Krisman Bertazi <krisman@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Conflicts:
	io_uring/io_uring.c

Signed-off-by: Baokun Li <libaokun1@huawei.com>