[18/18] bcache: avoid potential memleak of list of journal_replay(s) in the CACHE_SYNC branch of run_cache_set

Commit Message

Coly Li April 24, 2019, 4:48 p.m. UTC

From: Shenghui Wang <[e-mail]>

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 <[e-mail]>
Signed-off-by: Coly Li <[e-mail]>
---
 drivers/md/bcache/super.c | 8 ++++++++
 1 file changed, 8 insertions(+)

Patch

diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c
index 3f34b96ebbc3..0ffe9acee9d8 100644
--- a/drivers/md/bcache/super.c
+++ b/drivers/md/bcache/super.c
@@ -1790,6 +1790,8 @@  static int 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);
 
@@ -1949,6 +1951,12 @@  static int run_cache_set(struct cache_set *c)
 	set_bit(CACHE_SET_RUNNING, &c->flags);
 	return 0;
 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);