bcache: Fix a null ptr deref in journal replay

Signed-off-by: Kent Overstreet <kmo@daterainc.com>

1 files changed, 5 insertions, 1 deletions

diff --git a/drivers/md/bcache/journal.c b/drivers/md/bcache/journal.c
index e38c5997bf12..97e6a92da999 100644
--- a/drivers/md/bcache/journal.c
+++ b/drivers/md/bcache/journal.c
@@ -287,9 +287,13 @@ void bch_journal_mark(struct cache_set *c, struct list_head *list)
                      k < bset_bkey_last(&i->j);
                      k = bkey_next(k)) {
                         unsigned j;
+                        struct bucket *g;
 
                         for (j = 0; j < KEY_PTRS(k); j++) {
-                                struct bucket *g = PTR_BUCKET(c, k, j);
+                                if (!ptr_available(c, k, j))
+                                        continue;
+
+                                g = PTR_BUCKET(c, k, j);
                                 atomic_inc(&g->pin);
 
                                 if (g->prio == BTREE_PRIO &&