lkml.org 
[lkml]   [2020]   [Jun]   [21]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH v2] nbd: Fix memory leak in nbd_add_socket
From
Date

On 2020/6/20 20:05, Markus Elfring wrote:
>> 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?

em, how about this?


When adding first socket to nbd, if nsock's allocation fails, config->socks

is malloced but num_connections does not update, memory leak will
occur(Function

nbd_config_put will only free config->socks when num_connections is not 0).

>
>
> …
>> +++ 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);
>
>
> …
>> 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
>
> .
>

\
 
 \ /
  Last update: 2020-06-22 05:27    [W:0.038 / U:0.280 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site