stable inclusion
from stable-v5.10.149
commit 29f50bcf0f8b9e49c3c9b0e08fcae2ec3a88cc9f
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/I5W7AX
CVE: CVE-2022-3535

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

[ Upstream commit 0152dfee ]

When mvpp2 is unloaded, the driver specific debugfs directory is not
removed, which technically leads to a memory leak. However, this
directory is only created when the first device is probed, so the
hardware is present. Removing the module is only something a developer
would to when e.g. testing out changes, so the module would be
reloaded. So this memory leak is minor.

The original attempt in commit fe2c9c61 ("net: mvpp2: debugfs: fix
memory leak when using debugfs_lookup()") that was labelled as a memory
leak fix was not, it fixed a refcount leak, but in doing so created a
problem when the module is reloaded - the directory already exists, but
mvpp2_root is NULL, so we lose all debugfs entries. This fix has been
reverted.

This is the alternative fix, where we remove the offending directory
whenever the driver is unloaded.

Fixes: 21da57a2 ("net: mvpp2: add a debugfs interface for the Header Parser")
Signed-off-by: NRussell King (Oracle) <rmk+kernel@armlinux.org.uk>
Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: NMarcin Wojtas <mw@semihalf.com>
Link: https://lore.kernel.org/r/E1ofOAB-00CzkG-UO@rmk-PC.armlinux.org.ukSigned-off-by: NJakub Kicinski <kuba@kernel.org>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NHui Tang <tanghui20@huawei.com>
Reviewed-by: NZhang Qiao <zhangqiao22@huawei.com>
Reviewed-by: NXiu Jianfeng <xiujianfeng@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>