Re: [PATCH v2] nbd: Fix memory leak in nbd_add_socket
From: Markus Elfring <hidden>
Date: 2020-06-20 12:06:27
Also in:
kernel-janitors, lkml
If we add first socket to nbd, config->socks is malloced but num_connections does not update(nsock's allocation fail), the memory is leaked. Cause in later nbd_config_put(), will only free config->socks when num_connections is not 0. Let nsock's allocation first to avoid this.
I suggest to improve this change description. Can an other wording variant be nicer? …
quoted hunk
+++ b/drivers/block/nbd.c@@ -1037,21 +1037,22 @@ static int nbd_add_socket(struct nbd_device *nbd, unsigned long arg, return -EBUSY; } + nsock = kzalloc(sizeof(struct nbd_sock), GFP_KERNEL);
Please use the following code variant. https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/process/coding-style.rst?id=4333a9b0b67bb4e8bcd91bdd80da80b0ec151162#n854 + nsock = kzalloc(sizeof(*nsock), GFP_KERNEL); …
quoted hunk
if (!socks) { sockfd_put(sock); + kfree(nsock); return -ENOMEM; }
Please take another software design possibility into account.
if (!socks) {
- sockfd_put(sock);
- return -ENOMEM;
+ kfree(nsock);
+ goto put_socket;
}
Regards,
Markus