[PATCH] block: free q->flush_rq in blk_init_allocated_queue error paths

[PATCH] block: free q->flush_rq in blk_init_allocated_queue error paths

[Jens Axboe]

Hi Linus,

Turns out there was a potential leak in the error path of the flush
fixup from the last pull, which Dave Jones spotted.

Can you apply this to your current tree before tagging 3.14? Thanks!

From: Dave Jones <davej@redhat.com>

Commit 7982e90c3a ("block: fix q->flush_rq NULL pointer crash on
dm-mpath flush") moved an allocation to blk_init_allocated_queue(),
but neglected to free that allocation on the error paths that
follow.

Signed-off-by: Dave Jones <davej@fedoraproject.org>
Acked-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

diff --git a/block/blk-core.c b/block/blk-core.c
index 4cd5ffc18442..bfe16d5af9f9 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -713,7 +713,7 @@ blk_init_allocated_queue(struct request_queue *q, request_fn_proc *rfn,
 		return NULL;
 
 	if (blk_init_rl(&q->root_rl, q, GFP_KERNEL))
-		return NULL;
+		goto fail;
 
 	q->request_fn		= rfn;
 	q->prep_rq_fn		= NULL;
@@ -737,12 +737,16 @@ blk_init_allocated_queue(struct request_queue *q, request_fn_proc *rfn,
 	/* init elevator */
 	if (elevator_init(q, NULL)) {
 		mutex_unlock(&q->sysfs_lock);
-		return NULL;
+		goto fail;
 	}
 
 	mutex_unlock(&q->sysfs_lock);
 
 	return q;
+
+fail:
+	kfree(q->flush_rq);
+	return NULL;
 }
 EXPORT_SYMBOL(blk_init_allocated_queue);
 

-- 
Jens Axboe