From: "Russell King (Oracle)" rmk+kernel@armlinux.org.uk

mainline inclusion from mainline-v6.0-rc7 commit 0152dfee235e87660f52a117fc9f70dc55956bb4 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/I5W7AX CVE: CVE-2022-3535

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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 fe2c9c61f668 ("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: 21da57a23125 ("net: mvpp2: add a debugfs interface for the Header Parser") Signed-off-by: Russell King (Oracle) rmk+kernel@armlinux.org.uk Reviewed-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Reviewed-by: Marcin Wojtas mw@semihalf.com Link: https://lore.kernel.org/r/E1ofOAB-00CzkG-UO@rmk-PC.armlinux.org.uk Signed-off-by: Jakub Kicinski kuba@kernel.org

Conflicts: drivers/net/ethernet/marvell/mvpp2/mvpp2.h drivers/net/ethernet/marvell/mvpp2/mvpp2_debugfs.c Signed-off-by: Hui Tang tanghui20@huawei.com Reviewed-by: Zhang Qiao zhangqiao22@huawei.com Reviewed-by: Xiu Jianfeng xiujianfeng@huawei.com Signed-off-by: Yongqiang Liu liuyongqiang13@huawei.com --- drivers/net/ethernet/marvell/mvpp2/mvpp2.h | 1 + drivers/net/ethernet/marvell/mvpp2/mvpp2_debugfs.c | 10 ++++++++-- drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c | 13 ++++++++++++- 3 files changed, 21 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/marvell/mvpp2/mvpp2.h b/drivers/net/ethernet/marvell/mvpp2/mvpp2.h index 46911b67b039..23f60bc5d48f 100644 --- a/drivers/net/ethernet/marvell/mvpp2/mvpp2.h +++ b/drivers/net/ethernet/marvell/mvpp2/mvpp2.h @@ -1107,5 +1107,6 @@ void mvpp2_percpu_write_relaxed(struct mvpp2 *priv, int cpu, u32 offset, void mvpp2_dbgfs_init(struct mvpp2 *priv, const char *name);

void mvpp2_dbgfs_cleanup(struct mvpp2 *priv); +void mvpp2_dbgfs_exit(void);

#endif diff --git a/drivers/net/ethernet/marvell/mvpp2/mvpp2_debugfs.c b/drivers/net/ethernet/marvell/mvpp2/mvpp2_debugfs.c index f9744a61e5dd..d77414e1e704 100644 --- a/drivers/net/ethernet/marvell/mvpp2/mvpp2_debugfs.c +++ b/drivers/net/ethernet/marvell/mvpp2/mvpp2_debugfs.c @@ -660,6 +660,13 @@ static int mvpp2_dbgfs_port_init(struct dentry *parent, return 0; }

+static struct dentry *mvpp2_root; + +void mvpp2_dbgfs_exit(void) +{ + debugfs_remove(mvpp2_root); +} + void mvpp2_dbgfs_cleanup(struct mvpp2 *priv) { debugfs_remove_recursive(priv->dbgfs_dir); @@ -667,10 +674,9 @@ void mvpp2_dbgfs_cleanup(struct mvpp2 *priv)

void mvpp2_dbgfs_init(struct mvpp2 *priv, const char *name) { - struct dentry *mvpp2_dir, *mvpp2_root; + struct dentry *mvpp2_dir; int ret, i;

- mvpp2_root = debugfs_lookup(MVPP2_DRIVER_NAME, NULL); if (!mvpp2_root) { mvpp2_root = debugfs_create_dir(MVPP2_DRIVER_NAME, NULL); if (IS_ERR(mvpp2_root)) diff --git a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c index 04bee450eb3d..beb79455adc7 100644 --- a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c +++ b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c @@ -5412,7 +5412,18 @@ static struct platform_driver mvpp2_driver = { }, };

-module_platform_driver(mvpp2_driver); +static int __init mvpp2_driver_init(void) +{ + return platform_driver_register(&mvpp2_driver); +} +module_init(mvpp2_driver_init); + +static void __exit mvpp2_driver_exit(void) +{ + platform_driver_unregister(&mvpp2_driver); + mvpp2_dbgfs_exit(); +} +module_exit(mvpp2_driver_exit);

MODULE_DESCRIPTION("Marvell PPv2 Ethernet Driver - www.marvell.com"); MODULE_AUTHOR("Marcin Wojtas mw@semihalf.com");