From 72ce11ddfa4e9e1879103581a60b7e34547eaa0a Mon Sep 17 00:00:00 2001 From: Lv Yunlong Date: Mon, 26 Apr 2021 07:32:29 -0700 Subject: [PATCH] drivers/block/null_blk/main: Fix a double free in null_init. 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 Link: https://lore.kernel.org/r/20210426143229.7374-1-lyl2019@mail.ustc.edu.cn Signed-off-by: Jens Axboe --- 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 bfcab1c782b5..dae54dd1aeac 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,