From aba356616386e6e573a34c6d64ed12443686e5c8 Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Mon, 8 Aug 2016 14:20:23 -0500 Subject: ipcns: Add a limit on the number of ipc namespaces Acked-by: Kees Cook Signed-off-by: "Eric W. Biederman" --- ipc/namespace.c | 45 ++++++++++++++++++++++++++++++++++----------- 1 file changed, 34 insertions(+), 11 deletions(-) (limited to 'ipc') diff --git a/ipc/namespace.c b/ipc/namespace.c index d87e6baa1323..730914214135 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 @@ static void free_ipc_ns(struct ipc_namespace *ns) 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); -- cgit v1.2.3