drivers/block/null_blk/main: Fix a double free in null_init.

[ Upstream commit 72ce11ddfa4e9e1879103581a60b7e34547eaa0a ]

In null_init, null_add_dev(dev) is called.
In null_add_dev, it calls null_free_zoned_dev(dev) to free dev->zones
via kvfree(dev->zones) in out_cleanup_zone branch and returns err.
Then null_init accept the err code and then calls null_free_dev(dev).

But in null_free_dev(dev), dev->zones is freed again by
null_free_zoned_dev().

My patch set dev->zones to NULL in null_free_zoned_dev() after
kvfree(dev->zones) is called, to avoid the double free.

Fixes: 2984c8684f ("nullb: factor disk parameters")
Signed-off-by: Lv Yunlong <lyl2019@mail.ustc.edu.cn>
Link: https://lore.kernel.org/r/20210426143229.7374-1-lyl2019@mail.ustc.edu.cn
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Lv Yunlong 2021-04-26 07:32:29 -07:00 committed by Greg Kroah-Hartman
parent 94f1bdf01b
commit 5378c92425

View File

@ -149,6 +149,7 @@ void null_free_zoned_dev(struct nullb_device *dev)
{
bitmap_free(dev->zone_locks);
kvfree(dev->zones);
dev->zones = NULL;
}
static inline void null_lock_zone(struct nullb_device *dev, unsigned int zno)