net: make get_net_ns return error if NET_NS is disabled
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 <[email protected]>
Fixes: c62cce2caee5 ("net: add an ioctl to get a socket network namespace")
Cc: Cong Wang <[email protected]>
Cc: Jakub Kicinski <[email protected]>
Cc: David Laight <[email protected]>
Cc: Christian Brauner <[email protected]>
Suggested-by: Jakub Kicinski <[email protected]>
Acked-by: Christian Brauner <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
diff --git a/include/net/net_namespace.h b/include/net/net_namespace.h
index fa58871..6412d78 100644
--- a/include/net/net_namespace.h
+++ b/include/net/net_namespace.h
@@ -184,6 +184,8 @@ struct net *copy_net_ns(unsigned long flags, struct user_namespace *user_ns,
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);
#else /* CONFIG_NET_NS */
#include <linux/sched.h>
#include <linux/nsproxy.h>
@@ -203,6 +205,11 @@ 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);
+}
#endif /* CONFIG_NET_NS */
