ceph: Only allow mounts in the initial network namespace

Today ceph opens tcp sockets from a delayed work callback.  Delayed
work happens from kernel threads which are always in the initial
network namespace.   Therefore fail early if someone attempts
to mount a ceph filesystem from something other than the initial
network namespace.

Cc: Sage Weil <sage@inktank.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>

diff --git a/net/ceph/ceph_common.c b/net/ceph/ceph_common.c
index ee71ea26777ae892fafd13a8338b3f556d9f427b..1deb29af82fd2b10a2b578c4a11c362fa83d4ecf 100644 (file)
--- a/net/ceph/ceph_common.c
+++ b/net/ceph/ceph_common.c
@@ -15,6 +15,8 @@
 #include <linux/slab.h>
 #include <linux/statfs.h>
 #include <linux/string.h>
+#include <linux/nsproxy.h>
+#include <net/net_namespace.h>
 
 
 #include <linux/ceph/ceph_features.h>
@@ -292,6 +294,9 @@ ceph_parse_options(char *options, const char *dev_name,
        int err = -ENOMEM;
        substring_t argstr[MAX_OPT_ARGS];
 
+       if (current->nsproxy->net_ns != &init_net)
+               return ERR_PTR(-EINVAL);
+
        opt = kzalloc(sizeof(*opt), GFP_KERNEL);
        if (!opt)
                return ERR_PTR(-ENOMEM);