Patch "media: amphion: Fix error handling in vpu_driver_init()" has been added to the 6.1-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    media: amphion: Fix error handling in vpu_driver_init()

to the 6.1-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     media-amphion-fix-error-handling-in-vpu_driver_init.patch
and it can be found in the queue-6.1 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit a3dad3d3cc7c5422fe0bd9bee80982c888b43f91
Author: Yuan Can <yuancan@xxxxxxxxxx>
Date:   Fri Nov 11 06:09:26 2022 +0000

    media: amphion: Fix error handling in vpu_driver_init()
    
    [ 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@xxxxxxxxxx>
    Reviewed-by: ming_qian <ming.qian@xxxxxxx>
    Signed-off-by: Hans Verkuil <hverkuil-cisco@xxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

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)