This is a note to let you know that I've just added the patch titled
drivers/block/null_blk/main: Fix a double free in null_init.
to the 5.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
drivers-block-null_blk-main-fix-a-double-free-in-nul.patch
and it can be found in the queue-5.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 749ce6bf5999221983f06ff7a6024617bf007f2a
Author: Lv Yunlong <lyl2019@xxxxxxxxxxxxxxxx>
Date: Mon Apr 26 07:32:29 2021 -0700
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 <lyl2019@xxxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20210426143229.7374-1-lyl2019@xxxxxxxxxxxxxxxx
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/block/null_blk_zoned.c b/drivers/block/null_blk_zoned.c
index 172f720b8d63..f5df82c26c16 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)
