The patch below does not apply to the 5.14-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@xxxxxxxxxxxxxxx>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 8468f45091d2866affed6f6a7aecc20779139173 Mon Sep 17 00:00:00 2001
From: Coly Li <colyli@xxxxxxx>
Date: Wed, 3 Nov 2021 14:49:17 +0800
Subject: [PATCH] bcache: fix use-after-free problem in bcache_device_free()
In bcache_device_free(), pointer disk is referenced still in
ida_simple_remove() after blk_cleanup_disk() gets called on this
pointer. This may cause a potential panic by use-after-free on the
disk pointer.
This patch fixes the problem by calling blk_cleanup_disk() after
ida_simple_remove().
Fixes: bc70852fd104 ("bcache: convert to blk_alloc_disk/blk_cleanup_disk")
Signed-off-by: Coly Li <colyli@xxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Cc: Hannes Reinecke <hare@xxxxxxx>
Cc: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx # v5.14+
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
Link: https://lore.kernel.org/r/20211103064917.67383-1-colyli@xxxxxxx
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c
index 84a48eed8e24..a7bb3355b776 100644
--- a/drivers/md/bcache/super.c
+++ b/drivers/md/bcache/super.c
@@ -885,9 +885,9 @@ static void bcache_device_free(struct bcache_device *d)
bcache_device_detach(d);
if (disk) {
- blk_cleanup_disk(disk);
ida_simple_remove(&bcache_device_idx,
first_minor_to_idx(disk->first_minor));
+ blk_cleanup_disk(disk);
}
bioset_exit(&d->bio_split);
