From: Yuan Can Date: Tue, 8 Nov 2022 09:12:26 +0000 (+0000) Subject: drm/bridge: megachips: Fix error handling in i2c_register_driver() X-Git-Tag: v6.3-rc1~28^2~31^2~160 X-Git-Url: http://git.osdn.net/view?a=commitdiff_plain;h=4ecff954c370b82bce45bdca2846c5c5563e8a8a;p=tomoyo%2Ftomoyo-test1.git drm/bridge: megachips: Fix error handling in i2c_register_driver() 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 Reviewed-by: Andrzej Hajda Tested-by: Ian Ray Signed-off-by: Robert Foss Link: https://patchwork.freedesktop.org/patch/msgid/20221108091226.114524-1-yuancan@huawei.com --- 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 97359f807bfc..cbfa05a6767b 100644 --- a/drivers/gpu/drm/bridge/megachips-stdpxxxx-ge-b850v3-fw.c +++ b/drivers/gpu/drm/bridge/megachips-stdpxxxx-ge-b850v3-fw.c @@ -440,7 +440,11 @@ 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);