media: platform: exynos4-is: Fix error handling in fimc_md_init()

[ Upstream commit b434422c45282a0573d8123239abc41fa72665d4 ]

A problem about modprobe s5p_fimc failed is triggered with the
following log given:

 [  272.075275] Error: Driver 'exynos4-fimc' is already registered, aborting...
 modprobe: ERROR: could not insert 's5p_fimc': Device or resource busy

The reason is that fimc_md_init() returns platform_driver_register()
directly without checking its return value, if platform_driver_register()
failed, it returns without unregister fimc_driver, resulting the
s5p_fimc can never be installed later.
A simple call graph is shown as below:

 fimc_md_init()
   fimc_register_driver() # register fimc_driver
   platform_driver_register()
     platform_driver_register()
       driver_register()
         bus_add_driver()
           dev = kzalloc(...) # OOM happened
   # return without unregister fimc_driver

Fix by unregister fimc_driver when platform_driver_register() returns
error.

Fixes: d3953223b0 ("[media] s5p-fimc: Add the media device driver")
Signed-off-by: Yuan Can <yuancan@huawei.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Yuan Can 2022-11-11 06:08:53 +00:00 committed by Greg Kroah-Hartman
parent 7b02c50d39
commit 9ca9d7fd7d
2 changed files with 6 additions and 2 deletions

View File

@ -1231,7 +1231,7 @@ int __init fimc_register_driver(void)
return platform_driver_register(&fimc_driver); return platform_driver_register(&fimc_driver);
} }
void __exit fimc_unregister_driver(void) void fimc_unregister_driver(void)
{ {
platform_driver_unregister(&fimc_driver); platform_driver_unregister(&fimc_driver);
} }

View File

@ -1581,7 +1581,11 @@ static int __init fimc_md_init(void)
if (ret) if (ret)
return ret; return ret;
return platform_driver_register(&fimc_md_driver); ret = platform_driver_register(&fimc_md_driver);
if (ret)
fimc_unregister_driver();
return ret;
} }
static void __exit fimc_md_exit(void) static void __exit fimc_md_exit(void)