From: Changbin Du <changbin.du@gmail.com>
To: Alexander Viro <viro@zeniv.linux.org.uk>,
Jakub Kici nski <kuba@kernel.org>
Cc: "David S. Miller" <davem@davemloft.net>,
netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-fsdevel@vger.kernel.org,
Changbin Du <changbin.du@gmail.com>,
Cong Wang <xiyou.wangcong@gmail.com>,
David Laight <David.Laight@ACULAB.COM>,
Christian Brauner <christian.brauner@ubuntu.com>
Subject: [PATCH v3] net: make get_net_ns return error if NET_NS is disabled
Date: Thu, 10 Jun 2021 23:39:41 +0800 [thread overview]
Message-ID: <20210610153941.118945-1-changbin.du@gmail.com> (raw)
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(-)
diff --git a/include/linux/socket.h b/include/linux/socket.h
index b8fc5c53ba6f..0d8e3dcb7f88 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 0a25f95691d9..bdc0459a595e 100644
--- a/include/net/net_namespace.h
+++ b/include/net/net_namespace.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);
diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c
index 6a0d9583d69c..9b5a767eddd5 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 27e3e7d53f8e..4f2c6d2795d0 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;
--
2.30.2
next reply other threads:[~2021-06-10 15:40 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-10 15:39 Changbin Du [this message]
2021-06-10 17:51 ` [PATCH v3] net: make get_net_ns return error if NET_NS is disabled Jakub Kicinski
2021-06-11 13:53 ` Changbin Du
2021-06-10 21:18 ` David Miller
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20210610153941.118945-1-changbin.du@gmail.com \
--to=changbin.du@gmail.com \
--cc=David.Laight@ACULAB.COM \
--cc=christian.brauner@ubuntu.com \
--cc=davem@davemloft.net \
--cc=kuba@kernel.org \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=netdev@vger.kernel.org \
--cc=viro@zeniv.linux.org.uk \
--cc=xiyou.wangcong@gmail.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).