[PATCH 4.19 038/109] net: make get_net_ns return error if NET_NS is disabled
From: Sasha Levin <sashal@kernel.org>
Date: 2021-06-28 14:54:22
Also in:
lkml
Subsystem:
networking [general], networking [sockets], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Kuniyuki Iwashima, Willem de Bruijn, Linus Torvalds
From: Changbin Du <redacted>
[ 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 <redacted>
Fixes: c62cce2caee5 ("net: add an ioctl to get a socket network namespace")
Cc: Cong Wang <redacted>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: David Laight <redacted>
Cc: Christian Brauner <redacted>
Suggested-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: Christian Brauner <redacted>
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 cc1d3f1b7656..15a7eb24f63c 100644
--- a/include/linux/socket.h
+++ b/include/linux/socket.h@@ -384,6 +384,4 @@ extern int __sys_getpeername(int fd, struct sockaddr __user *usockaddr, extern int __sys_socketpair(int family, int type, int protocol, int __user *usockvec); 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 5007eaba207d..bc88ac6c2e1d 100644
--- a/include/net/net_namespace.h
+++ b/include/net/net_namespace.h@@ -175,6 +175,8 @@ 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>
@@ -194,6 +196,11 @@ 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 c60123dff803..939d8a31eb82 100644
--- a/net/core/net_namespace.c
+++ b/net/core/net_namespace.c@@ -598,6 +598,18 @@ 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 1ed7be54815a..f14bca00ff01 100644
--- a/net/socket.c
+++ b/net/socket.c@@ -1048,19 +1048,6 @@ 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;
--
2.30.2