dm cache: handle kmalloc failure allocating background_tracker struct
Currently there is no kmalloc failure check on the allocation of
the background_tracker struct in btracker_create(), and so a NULL return
will lead to a NULL pointer dereference. Add a NULL check.
Detected by CoverityScan, CID#1416587 ("Dereference null return value")
Fixes: b29d4986d ("dm cache: significant rework to leverage dm-bio-prison-v2")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
diff --git a/drivers/md/dm-cache-background-tracker.c b/drivers/md/dm-cache-background-tracker.c
index 9b1afdf..7072338 100644
--- a/drivers/md/dm-cache-background-tracker.c
+++ b/drivers/md/dm-cache-background-tracker.c
@@ -33,6 +33,11 @@ struct background_tracker *btracker_create(unsigned max_work)
{
struct background_tracker *b = kmalloc(sizeof(*b), GFP_KERNEL);
+ if (!b) {
+ DMERR("couldn't create background_tracker");
+ return NULL;
+ }
+
b->max_work = max_work;
atomic_set(&b->pending_promotes, 0);
atomic_set(&b->pending_writebacks, 0);