mmc: queue: Improve error handling during allocation of bounce buffers

Allocation of previous bounce buffer in mmc_init_queue when the current
bounce buffer allocation fails was leading to a crash later in
__blk_segment_map_sg. Error handling is improved by allocating previous
bounce buffer only if the current bounce buffer allocation succeeds.

Signed-off-by: Bhuvanesh Surachari <bhuvanesh_surachari@mentor.com>
Signed-off-by: Harish Jenny K N <harish_kandiga@mentor.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

1 files changed, 9 insertions, 7 deletions

diff --git a/drivers/mmc/card/queue.c b/drivers/mmc/card/queue.c
index cfa6110632c3..236d194c2883 100644
--- a/drivers/mmc/card/queue.c
+++ b/drivers/mmc/card/queue.c
@@ -232,13 +232,15 @@ int mmc_init_queue(struct mmc_queue *mq, struct mmc_card *card,
                         if (!mqrq_cur->bounce_buf) {
                                 pr_warn("%s: unable to allocate bounce cur buffer\n",
                                         mmc_card_name(card));
-                        }
-                        mqrq_prev->bounce_buf = kmalloc(bouncesz, GFP_KERNEL);
-                        if (!mqrq_prev->bounce_buf) {
-                                pr_warn("%s: unable to allocate bounce prev buffer\n",
-                                        mmc_card_name(card));
-                                kfree(mqrq_cur->bounce_buf);
-                                mqrq_cur->bounce_buf = NULL;
+                        } else {
+                                mqrq_prev->bounce_buf =
+                                                kmalloc(bouncesz, GFP_KERNEL);
+                                if (!mqrq_prev->bounce_buf) {
+                                        pr_warn("%s: unable to allocate bounce prev buffer\n",
+                                                mmc_card_name(card));
+                                        kfree(mqrq_cur->bounce_buf);
+                                        mqrq_cur->bounce_buf = NULL;
+                                }
                         }
                 }