[PATCH] nvmet: Replace sock_create with sock_create_kern

[Peijie Shao]

On 3/25/2025 5:04 AM, David Laight wrote:
> On Mon, 24 Mar 2025 11:17:08 +0800
> shaopeijie at cestc.cn wrote:
> 
>> From: Peijie Shao <shaopeijie at cestc.cn>
>>
>> Replacing sock_create() with sock_create_kern()
>> changes the socket object's label to kernel_t,
>> thereby bypassing unnecessary SELinux permission
>> checks. It also helps to avoid copy and paste bugs.
> 
> Does sock_create_kern() hold a reference on the namespace?
> It hadn't used to and sock_create() will take one.
> 
> 	David
> 
>>
>> Signed-off-by: Peijie Shao <shaopeijie at cestc.cn>
>> ---
>>   drivers/nvme/target/tcp.c | 3 ++-
>>   1 file changed, 2 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/nvme/target/tcp.c b/drivers/nvme/target/tcp.c
>> index 4f9cac8a5abe..216afacc8179 100644
>> --- a/drivers/nvme/target/tcp.c
>> +++ b/drivers/nvme/target/tcp.c
>> @@ -2049,7 +2049,8 @@ static int nvmet_tcp_add_port(struct nvmet_port *nport)
>>   	if (port->nport->inline_data_size < 0)
>>   		port->nport->inline_data_size = NVMET_TCP_DEF_INLINE_DATA_SIZE;
>>   
>> -	ret = sock_create(port->addr.ss_family, SOCK_STREAM,
>> +	ret = sock_create_kern(current->nsproxy->net_ns,
>> +				port->addr.ss_family, SOCK_STREAM,
>>   				IPPROTO_TCP, &port->sock);
>>   	if (ret) {
>>   		pr_err("failed to create a socket\n");
> 
> 
> 

Thanks for reviewing. Indeed, there is a netns UAF issue. The call path 
sock_create() -> __sock_create() -> inet_create() -> sk_alloc() takes a 
reference of the given netns, however sock_create_kern() doesn't perform 
this step.

Sorroy the patch for the host side '[PATCH] nvme-tcp: fix selinux denied 
when calling sock_sendmsg' has the same problem.

I will send a v2 patch to fix both host and target side soon, thanks.