From 7e1b9521f5a8356553f5e58b07952bf346632ea4 Mon Sep 17 00:00:00 2001 From: Colin Ian King Date: Sat, 11 Mar 2017 19:09:45 +0000 Subject: [PATCH] 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 Signed-off-by: Mike Snitzer --- drivers/md/dm-cache-background-tracker.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/md/dm-cache-background-tracker.c b/drivers/md/dm-cache-background-tracker.c index 9b1afdfb13f0..707233891291 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); -- 2.30.2