This is a note to let you know that I've just added the patch titled drm/bridge: megachips: Fix error handling in i2c_register_driver() to the 5.10-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: drm-bridge-megachips-fix-error-handling-in-i2c_regis.patch and it can be found in the queue-5.10 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit aee6631aedf1b4e37252a2cb9a0b71986655257e Author: Yuan Can <yuancan@xxxxxxxxxx> Date: Tue Nov 8 09:12:26 2022 +0000 drm/bridge: megachips: Fix error handling in i2c_register_driver() [ Upstream commit 4ecff954c370b82bce45bdca2846c5c5563e8a8a ] A problem about insmod megachips-stdpxxxx-ge-b850v3-fw.ko failed is triggered with the following log given: [ 4497.981497] Error: Driver 'stdp4028-ge-b850v3-fw' is already registered, aborting... insmod: ERROR: could not insert module megachips-stdpxxxx-ge-b850v3-fw.ko: Device or resource busy The reason is that stdpxxxx_ge_b850v3_init() returns i2c_add_driver() directly without checking its return value, if i2c_add_driver() failed, it returns without calling i2c_del_driver() on the previous i2c driver, resulting the megachips-stdpxxxx-ge-b850v3-fw can never be installed later. A simple call graph is shown as below: stdpxxxx_ge_b850v3_init() i2c_add_driver(&stdp4028_ge_b850v3_fw_driver) i2c_add_driver(&stdp2690_ge_b850v3_fw_driver) i2c_register_driver() driver_register() bus_add_driver() priv = kzalloc(...) # OOM happened # return without delete stdp4028_ge_b850v3_fw_driver Fix by calling i2c_del_driver() on stdp4028_ge_b850v3_fw_driver when i2c_add_driver() returns error. Fixes: fcfa0ddc18ed ("drm/bridge: Drivers for megachips-stdpxxxx-ge-b850v3-fw (LVDS-DP++)") Signed-off-by: Yuan Can <yuancan@xxxxxxxxxx> Reviewed-by: Andrzej Hajda <andrzej.hajda@xxxxxxxxx> Tested-by: Ian Ray <ian.ray@xxxxxx> Signed-off-by: Robert Foss <robert.foss@xxxxxxxxxx> Link: https://patchwork.freedesktop.org/patch/msgid/20221108091226.114524-1-yuancan@xxxxxxxxxx Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/gpu/drm/bridge/megachips-stdpxxxx-ge-b850v3-fw.c b/drivers/gpu/drm/bridge/megachips-stdpxxxx-ge-b850v3-fw.c index 72248a565579e..e41afcc5326b1 100644 --- a/drivers/gpu/drm/bridge/megachips-stdpxxxx-ge-b850v3-fw.c +++ b/drivers/gpu/drm/bridge/megachips-stdpxxxx-ge-b850v3-fw.c @@ -444,7 +444,11 @@ static int __init stdpxxxx_ge_b850v3_init(void) if (ret) return ret; - return i2c_add_driver(&stdp2690_ge_b850v3_fw_driver); + ret = i2c_add_driver(&stdp2690_ge_b850v3_fw_driver); + if (ret) + i2c_del_driver(&stdp4028_ge_b850v3_fw_driver); + + return ret; } module_init(stdpxxxx_ge_b850v3_init);