From: Changbin Du changbin.du@gmail.com
[ Upstream commit ea6932d70e223e02fea3ae20a4feff05d7c1ea9a ]
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 Fixes: c62cce2caee5 ("net: add an ioctl to get a socket network namespace") 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 Acked-by: Christian Brauner christian.brauner@ubuntu.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- include/linux/socket.h | 2 -- include/net/net_namespace.h | 7 +++++++ net/core/net_namespace.c | 12 ++++++++++++ net/socket.c | 13 ------------- 4 files changed, 19 insertions(+), 15 deletions(-)
diff --git a/include/linux/socket.h b/include/linux/socket.h index 385894b4a8bb..42222a84167f 100644 --- a/include/linux/socket.h +++ b/include/linux/socket.h @@ -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 */ diff --git a/include/net/net_namespace.h b/include/net/net_namespace.h index dcaee24a4d87..14b6f7f44532 100644 --- a/include/net/net_namespace.h +++ b/include/net/net_namespace.h @@ -197,6 +197,8 @@ 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> @@ -216,6 +218,11 @@ 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 */
diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c index 43b6ac4c4439..cc8dafb25d61 100644 --- a/net/core/net_namespace.c +++ b/net/core/net_namespace.c @@ -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; diff --git a/net/socket.c b/net/socket.c index 84a8049c2b09..03259cb919f7 100644 --- a/net/socket.c +++ b/net/socket.c @@ -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;