| Message ID | 20210610153941.118945-1-changbin.du@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v3] net: make get_net_ns return error if NET_NS is disabled | expand |
On Thu, 10 Jun 2021 23:39:41 +0800 Changbin Du wrote: > 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. I'm assuming you went from EOPNOTSUPP to EINVAL to follow what the existing helpers in the header do? Acked-by: Jakub Kicinski <kuba@kernel.org> Thanks!
From: Changbin Du <changbin.du@gmail.com> Date: Thu, 10 Jun 2021 23:39:41 +0800 > 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> As this is a bug fix please rebase on the 'net' tree and provide a proper Fixes: tag. Thank you.
On Thu, Jun 10, 2021 at 10:51:12AM -0700, Jakub Kicinski wrote: > On Thu, 10 Jun 2021 23:39:41 +0800 Changbin Du wrote: > > 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. > > I'm assuming you went from EOPNOTSUPP to EINVAL to follow what the > existing helpers in the header do? > yes, make them behaviour in the same manner. > Acked-by: Jakub Kicinski <kuba@kernel.org> > > Thanks!
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;
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(-)