stable inclusion
from stable-v5.10.121
commit 2401f1cf3dee6974d799a4387f0c5d98cec29326
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I5L6CQ

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=2401f1cf3dee6974d799a4387f0c5d98cec29326

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

commit fc873834 upstream.

The bug is here:
	if (!rdev)

The list iterator value 'rdev' will *always* be set and non-NULL
by rdev_for_each(), so it is incorrect to assume that the iterator
value will be NULL if the list is empty or no element found.
Otherwise it will bypass the NULL check and lead to invalid memory
access passing the check.

To fix the bug, use a new variable 'iter' as the list iterator,
while using the original variable 'rdev' as a dedicated pointer to
point to the found element.

Cc: stable@vger.kernel.org
Fixes: 2aa82191 ("md-cluster: Perform a lazy update")
Acked-by: NGuoqing Jiang <guoqing.jiang@linux.dev>
Signed-off-by: NXiaomeng Tong <xiam0nd.tong@gmail.com>
Acked-by: NGoldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: NSong Liu <song@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>
Acked-by: NXie XiuQi <xiexiuqi@huawei.com>