block: bfq: swap puts in bfqg_and_blkg_put

Fix trivial use-after-free. This could be last reference to bfqg. Fixes: 8f9bebc ("block, bfq: access and cache blkg data only when safe") Acked-by: Paolo Valente <paolo.valente@linaro.org> Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Signed-off-by: Jens Axboe <axboe@kernel.dk>
mariux64 · Sep 6, 2018 · d5274b3 · d5274b3
1 parent 8b2ded1
commit d5274b3
Showing 1 changed file with 2 additions and 2 deletions.
diff --git a/block/bfq-cgroup.c b/block/bfq-cgroup.c
@@ -275,9 +275,9 @@ static void bfqg_and_blkg_get(struct bfq_group *bfqg)
 
 void bfqg_and_blkg_put(struct bfq_group *bfqg)
 {
-	bfqg_put(bfqg);
-
 	blkg_put(bfqg_to_blkg(bfqg));
+
+	bfqg_put(bfqg);
 }
 
 /* @stats = 0 */