@@ -438,6 +438,4 @@ extern int __sys_socketpair(int family, int type, int protocol,
int __user *usockvec);
extern int __sys_shutdown_sock(struct socket *sock, int how);
extern int __sys_shutdown(int fd, int how);
-
-extern struct ns_common *get_net_ns(struct ns_common *ns);
#endif /* _LINUX_SOCKET_H */
@@ -185,6 +185,7 @@ void net_ns_get_ownership(const struct net *net, kuid_t *uid, kgid_t *gid);
void net_ns_barrier(void);
+struct ns_common *get_net_ns(struct ns_common *ns);
struct net *get_net_ns_by_fd(int fd);
#else /* CONFIG_NET_NS */
#include <linux/sched.h>
@@ -206,6 +207,11 @@ static inline void net_ns_get_ownership(const struct net *net,
static inline void net_ns_barrier(void) {}
+static inline struct ns_common *get_net_ns(struct ns_common *ns)
+{
+ return ERR_PTR(-EINVAL);
+}
+
static inline struct net *get_net_ns_by_fd(int fd)
{
return ERR_PTR(-EINVAL);
@@ -641,6 +641,18 @@ void __put_net(struct net *net)
}
EXPORT_SYMBOL_GPL(__put_net);
+/**
+ * get_net_ns - increment the refcount of the network namespace
+ * @ns: common namespace (net)
+ *
+ * Returns the net's common namespace.
+ */
+struct ns_common *get_net_ns(struct ns_common *ns)
+{
+ return &get_net(container_of(ns, struct net, ns))->ns;
+}
+EXPORT_SYMBOL_GPL(get_net_ns);
+
struct net *get_net_ns_by_fd(int fd)
{
struct file *file;
@@ -1072,19 +1072,6 @@ static long sock_do_ioctl(struct net *net, struct socket *sock,
* what to do with it - that's up to the protocol still.
*/
-/**
- * get_net_ns - increment the refcount of the network namespace
- * @ns: common namespace (net)
- *
- * Returns the net's common namespace.
- */
-
-struct ns_common *get_net_ns(struct ns_common *ns)
-{
- return &get_net(container_of(ns, struct net, ns))->ns;
-}
-EXPORT_SYMBOL_GPL(get_net_ns);
-
static long sock_ioctl(struct file *file, unsigned cmd, unsigned long arg)
{
struct socket *sock;
There is a panic in socket ioctl cmd SIOCGSKNS when NET_NS is not enabled. The reason is that nsfs tries to access ns->ops but the proc_ns_operations is not implemented in this case. [7.670023] Unable to handle kernel NULL pointer dereference at virtual address 00000010 [7.670268] pgd = 32b54000 [7.670544] [00000010] *pgd=00000000 [7.671861] Internal error: Oops: 5 [#1] SMP ARM [7.672315] Modules linked in: [7.672918] CPU: 0 PID: 1 Comm: systemd Not tainted 5.13.0-rc3-00375-g6799d4f2da49 #16 [7.673309] Hardware name: Generic DT based system [7.673642] PC is at nsfs_evict+0x24/0x30 [7.674486] LR is at clear_inode+0x20/0x9c The same to tun SIOCGSKNS command. To fix this problem, we make get_net_ns() return -EINVAL when NET_NS is disabled. Meanwhile move it to right place net/core/net_namespace.c. Signed-off-by: Changbin Du <changbin.du@gmail.com> Cc: Cong Wang <xiyou.wangcong@gmail.com> Cc: Jakub Kicinski <kuba@kernel.org> Cc: David Laight <David.Laight@ACULAB.COM> Cc: Christian Brauner <christian.brauner@ubuntu.com> Suggested-by: Jakub Kicinski <kuba@kernel.org> --- Patch "net: make get_net_ns_by_fd inline if NET_NS is disabled" must be applied first. --- include/linux/socket.h | 2 -- include/net/net_namespace.h | 6 ++++++ net/core/net_namespace.c | 12 ++++++++++++ net/socket.c | 13 ------------- 4 files changed, 18 insertions(+), 15 deletions(-)