From: Lv Yunlong Date: Mon, 26 Apr 2021 14:32:29 +0000 (-0700) Subject: drivers/block/null_blk/main: Fix a double free in null_init. X-Git-Tag: v5.10.37~184 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=5378c92425f3dfdc6306de98ad9ad9edfe98880a;p=thirdparty%2Fkernel%2Fstable.git 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: 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 Signed-off-by: Sasha Levin --- diff --git a/drivers/block/null_blk_zoned.c b/drivers/block/null_blk_zoned.c index 172f720b8d637..f5df82c26c16f 100644 --- a/drivers/block/null_blk_zoned.c +++ b/drivers/block/null_blk_zoned.c @@ -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)