[PATCH 6.1 0357/1146] media: amphion: Fix error handling in vpu_driver_init()

Greg Kroah-Hartman
2022-12-28T15:45:28Z

From: Yuan Can <yuancan@huawei.com>

[ Upstream commit a95cc6d11aae16a7b2d043b073a40de81bbea689 ]

A problem about modprobe amphion-vpu failed is triggered with the
following log given:

[ 2208.634841] Error: Driver 'amphion-vpu' is already registered, aborting...
modprobe: ERROR: could not insert 'amphion_vpu': Device or resource busy

The reason is that vpu_driver_init() returns vpu_core_driver_init()
directly without checking its return value, if vpu_core_driver_init()
failed, it returns without unregister amphion_vpu_driver, resulting the
amphion-vpu can never be installed later.
A simple call graph is shown as below:

vpu_driver_init()
platform_driver_register() # register amphion_vpu_driver
vpu_core_driver_init()
platform_driver_register()
driver_register()
bus_add_driver()
dev = kzalloc(...) # OOM happened
# return without unregister amphion_vpu_driver

Fix by unregister amphion_vpu_driver when vpu_core_driver_init() returns
error.

Fixes: b50a64fc54af ("media: amphion: add amphion vpu device driver")
Signed-off-by: Yuan Can <yuancan@huawei.com>
Reviewed-by: ming_qian <ming.qian@nxp.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/media/platform/amphion/vpu_drv.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/media/platform/amphion/vpu_drv.c b/drivers/media/platform/amphion/vpu_drv.c
index 9d5a5075343d..f01ce49d27e8 100644
--- a/drivers/media/platform/amphion/vpu_drv.c
+++ b/drivers/media/platform/amphion/vpu_drv.c
@@ -245,7 +245,11 @@ static int __init vpu_driver_init(void)
if (ret)
return ret;

- return vpu_core_driver_init();
+ ret = vpu_core_driver_init();
+ if (ret)
+ platform_driver_unregister(&amphion_vpu_driver);
+
+ return ret;
}

static void __exit vpu_driver_exit(void)
--
2.35.1