From a52f6b2f57b6695fa46d1b3cb37c54e16efabf53 Mon Sep 17 00:00:00 2001
From: Alexander Kappner <agk@godking.net>
Date: Wed, 28 Mar 2018 15:18:31 -0700
Subject: [PATCH] mmc: core: Prevent bus reference leak in mmc_blk_init()
commit d0a0852b9f81cf5f793bf2eae7336ed40a1a1815 upstream.
Upon module load, mmc_block allocates a bus with bus_registeri() in
mmc_blk_init(). This reference never gets freed during module unload, which
leads to subsequent re-insertions of the module fails and a WARN() splat is
triggered.
Fix the bug by dropping the reference for the bus in mmc_blk_exit().
Signed-off-by: Alexander Kappner <agk@godking.net>
Fixes: 97548575bef3 ("mmc: block: Convert RPMB to a character device")
Cc: <stable@vger.kernel.org>
Reviewed-by: Shawn Lin <shawn.lin@rock-chips.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Cc: Jisheng Zhang <Jisheng.Zhang@synaptics.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/mmc/core/block.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/mmc/core/block.c b/drivers/mmc/core/block.c
index df9903ee1fae..a9ce192828b8 100644
--- a/drivers/mmc/core/block.c
+++ b/drivers/mmc/core/block.c
@@ -2904,6 +2904,7 @@ static void __exit mmc_blk_exit(void)
mmc_unregister_driver(&mmc_driver);
unregister_blkdev(MMC_BLOCK_MAJOR, "mmc");
unregister_chrdev_region(mmc_rpmb_devt, MAX_DEVICES);
+ bus_unregister(&mmc_rpmb_bus_type);
}
module_init(mmc_blk_init);