On Mon, May 31, 2021 at 08:30:58AM +0000, David Laight wrote:
From: Cong Wang
Sent: 29 May 2021 20:15
On Fri, May 28, 2021 at 11:08 PM Changbin Du changbin.du@gmail.com wrote:
diff --git a/net/socket.c b/net/socket.c index 27e3e7d53f8e..644b46112d35 100644 --- a/net/socket.c +++ b/net/socket.c @@ -1149,11 +1149,15 @@ static long sock_ioctl(struct file *file, unsigned cmd, unsigned long arg) mutex_unlock(&vlan_ioctl_mutex); break; case SIOCGSKNS: +#ifdef CONFIG_NET_NS err = -EPERM; if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) break;
err = open_related_ns(&net->ns, get_net_ns);+#else
err = -ENOTSUPP;+#endif
I wonder if it is easier if we just reject ns->ops==NULL case in open_related_ns(). For 1) we can save an ugly #ifdef here; 2) drivers/net/tun.c has the same bugs.
If CONFIG_NET_NS is unset then why not make both ns_capable() and open_related_ns() unconditionally return -ENOTSUPP?
Here is the new fix that reject creating indoe for disabled ns. --- a/fs/nsfs.c +++ b/fs/nsfs.c @@ -62,6 +62,10 @@ static int __ns_get_path(struct path *path, struct ns_common *ns) struct inode *inode; unsigned long d;
+ /* In case the namespace is not actually enabled. */ + if (!ns->ops) + return -EOPNOTSUPP;
David
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