[PATCH 4.19 270/306] nbd: prevent memory leak

[Greg Kroah-Hartman]

From: Navid Emamdoost <navid.emamdoost@xxxxxxxxx>

commit 03bf73c315edca28f47451913177e14cd040a216 upstream.

In nbd_add_socket when krealloc succeeds, if nsock's allocation fail the
reallocted memory is leak. The correct behaviour should be assigning the
reallocted memory to config->socks right after success.

Reviewed-by: Josef Bacik <josef@xxxxxxxxxxxxxx>
Signed-off-by: Navid Emamdoost <navid.emamdoost@xxxxxxxxx>
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/block/nbd.c |    5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

--- a/drivers/block/nbd.c
+++ b/drivers/block/nbd.c
@@ -984,14 +984,15 @@ static int nbd_add_socket(struct nbd_dev
 		sockfd_put(sock);
 		return -ENOMEM;
 	}
+
+	config->socks = socks;
+
 	nsock = kzalloc(sizeof(struct nbd_sock), GFP_KERNEL);
 	if (!nsock) {
 		sockfd_put(sock);
 		return -ENOMEM;
 	}
 
-	config->socks = socks;
-
 	nsock->fallback_index = -1;
 	nsock->dead = false;
 	mutex_init(&nsock->tx_lock);