From: Lv Yunlong lyl2019@mail.ustc.edu.cn
[ 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: 2984c8684f962 ("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 --- drivers/block/null_blk/zoned.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/drivers/block/null_blk/zoned.c b/drivers/block/null_blk/zoned.c index fce0a54df0e5..8e0656964f1c 100644 --- a/drivers/block/null_blk/zoned.c +++ b/drivers/block/null_blk/zoned.c @@ -180,6 +180,7 @@ int null_register_zoned_dev(struct nullb *nullb) void null_free_zoned_dev(struct nullb_device *dev) { kvfree(dev->zones); + dev->zones = NULL; }
int null_report_zones(struct gendisk *disk, sector_t sector,