[PATCH 6.1 0689/1146] serial: 8250_bcm7271: Fix error handling in brcmuart_init()

Greg Kroah-Hartman
2022-12-28T16:25:42Z

From: Yuan Can <yuancan@huawei.com>

[ Upstream commit 6a3ff858915fa8ca36c7eb02c87c9181ae2fc333 ]

A problem about 8250_bcm7271 create debugfs failed is triggered with the
following log given:

[ 324.516635] debugfs: Directory 'bcm7271-uart' with parent '/' already present!

The reason is that brcmuart_init() returns platform_driver_register()
directly without checking its return value, if platform_driver_register()
failed, it returns without destroy the newly created debugfs, resulting
the debugfs of 8250_bcm7271 can never be created later.

brcmuart_init()
debugfs_create_dir() # create debugfs directory
platform_driver_register()
driver_register()
bus_add_driver()
priv = kzalloc(...) # OOM happened
# return without destroy debugfs directory

Fix by removing debugfs when platform_driver_register() returns error.

Fixes: 41a469482de2 ("serial: 8250: Add new 8250-core based Broadcom STB driver")
Signed-off-by: Yuan Can <yuancan@huawei.com>
Link: https://lore.kernel.org/r/20221109072110.117291-2-yuancan@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/tty/serial/8250/8250_bcm7271.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/drivers/tty/serial/8250/8250_bcm7271.c b/drivers/tty/serial/8250/8250_bcm7271.c
index fa8ccf204d86..89bfcefbea84 100644
--- a/drivers/tty/serial/8250/8250_bcm7271.c
+++ b/drivers/tty/serial/8250/8250_bcm7271.c
@@ -1212,9 +1212,17 @@ static struct platform_driver brcmuart_platform_driver = {

static int __init brcmuart_init(void)
{
+ int ret;
+
brcmuart_debugfs_root = debugfs_create_dir(
brcmuart_platform_driver.driver.name, NULL);
- return platform_driver_register(&brcmuart_platform_driver);
+ ret = platform_driver_register(&brcmuart_platform_driver);
+ if (ret) {
+ debugfs_remove_recursive(brcmuart_debugfs_root);
+ return ret;
+ }
+
+ return 0;
}
module_init(brcmuart_init);

--
2.35.1