Re: [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@xxxxxxxx wrote:
>
> > From: Peijie Shao <shaopeijie@xxxxxxxx>
> >
> > 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@xxxxxxxx>
> > ---
> >   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.