[PATCH 5.0 116/346] bcache: avoid potential memleak of list of journal_replay(s) in the CACHE_SYNC branch of run_cache_set

[Greg Kroah-Hartman]

[ Upstream commit 95f18c9d1310730d075499a75aaf13bcd60405a7 ]

In the CACHE_SYNC branch of run_cache_set(), LIST_HEAD(journal) is used
to collect journal_replay(s) and filled by bch_journal_read().

If all goes well, bch_journal_replay() will release the list of
jounal_replay(s) at the end of the branch.

If something goes wrong, code flow will jump to the label "err:" and leave
the list unreleased.

This patch will release the list of journal_replay(s) in the case of
error detected.

v1 -> v2:
* Move the release code to the location after label 'err:' to
  simply the change.

Signed-off-by: Shenghui Wang <shh...@foxmail.com>
Signed-off-by: Coly Li <col...@suse.de>
Signed-off-by: Jens Axboe <ax...@kernel.dk>
Signed-off-by: Sasha Levin <sas...@kernel.org>
---
 drivers/md/bcache/super.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c
index ee36e6b3bcad3..acf8e2e3890c7 100644
--- a/drivers/md/bcache/super.c
+++ b/drivers/md/bcache/super.c
@@ -1782,6 +1782,8 @@ static void run_cache_set(struct cache_set *c)
        struct cache *ca;
        struct closure cl;
        unsigned int i;
+       LIST_HEAD(journal);
+       struct journal_replay *l;
 
        closure_init_stack(&cl);
 
@@ -1939,6 +1941,12 @@ static void run_cache_set(struct cache_set *c)
        set_bit(CACHE_SET_RUNNING, &c->flags);
        return;
 err:
+       while (!list_empty(&journal)) {
+               l = list_first_entry(&journal, struct journal_replay, list);
+               list_del(&l->list);
+               kfree(l);
+       }
+
        closure_sync(&cl);
        /* XXX: test this, it's broken */
        bch_cache_set_error(c, "%s", err);
-- 
2.20.1