ipcns: Add a limit on the number of ipc namespaces
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
diff --git a/ipc/namespace.c b/ipc/namespace.c
index d87e6ba..7309142 100644
--- a/ipc/namespace.c
+++ b/ipc/namespace.c
@@ -16,39 +16,61 @@
#include "util.h"
+static struct ucounts *inc_ipc_namespaces(struct user_namespace *ns)
+{
+ return inc_ucount(ns, current_euid(), UCOUNT_IPC_NAMESPACES);
+}
+
+static void dec_ipc_namespaces(struct ucounts *ucounts)
+{
+ dec_ucount(ucounts, UCOUNT_IPC_NAMESPACES);
+}
+
static struct ipc_namespace *create_ipc_ns(struct user_namespace *user_ns,
struct ipc_namespace *old_ns)
{
struct ipc_namespace *ns;
+ struct ucounts *ucounts;
int err;
+ err = -ENFILE;
+ ucounts = inc_ipc_namespaces(user_ns);
+ if (!ucounts)
+ goto fail;
+
+ err = -ENOMEM;
ns = kmalloc(sizeof(struct ipc_namespace), GFP_KERNEL);
if (ns == NULL)
- return ERR_PTR(-ENOMEM);
+ goto fail_dec;
err = ns_alloc_inum(&ns->ns);
- if (err) {
- kfree(ns);
- return ERR_PTR(err);
- }
+ if (err)
+ goto fail_free;
ns->ns.ops = &ipcns_operations;
atomic_set(&ns->count, 1);
ns->user_ns = get_user_ns(user_ns);
+ ns->ucounts = ucounts;
err = mq_init_ns(ns);
- if (err) {
- put_user_ns(ns->user_ns);
- ns_free_inum(&ns->ns);
- kfree(ns);
- return ERR_PTR(err);
- }
+ if (err)
+ goto fail_put;
sem_init_ns(ns);
msg_init_ns(ns);
shm_init_ns(ns);
return ns;
+
+fail_put:
+ put_user_ns(ns->user_ns);
+ ns_free_inum(&ns->ns);
+fail_free:
+ kfree(ns);
+fail_dec:
+ dec_ipc_namespaces(ucounts);
+fail:
+ return ERR_PTR(err);
}
struct ipc_namespace *copy_ipcs(unsigned long flags,
@@ -96,6 +118,7 @@
msg_exit_ns(ns);
shm_exit_ns(ns);
+ dec_ipc_namespaces(ns->ucounts);
put_user_ns(ns->user_ns);
ns_free_inum(&ns->ns);
kfree(ns);