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| author | Eric W. Biederman <ebiederm@xmission.com> | 2016-08-08 14:20:23 -0500 |
|---|---|---|
| committer | Eric W. Biederman <ebiederm@xmission.com> | 2016-08-08 14:42:03 -0500 |
| commit | aba356616386e6e573a34c6d64ed12443686e5c8 (patch) | |
| tree | 6dd896d8191f5893ba69251e6916b22929579a8e | |
| parent | f7af3d1c03136275b876f58644599b120cf4ffdd (diff) | |
| download | linux-aba356616386e6e573a34c6d64ed12443686e5c8.tar.gz | |
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>
| -rw-r--r-- | include/linux/ipc_namespace.h | 1 | ||||
| -rw-r--r-- | include/linux/user_namespace.h | 1 | ||||
| -rw-r--r-- | ipc/namespace.c | 45 | ||||
| -rw-r--r-- | kernel/ucount.c | 1 |
4 files changed, 37 insertions, 11 deletions
diff --git a/include/linux/ipc_namespace.h b/include/linux/ipc_namespace.h index d10e54f03c09..848e5796400e 100644 --- a/include/linux/ipc_namespace.h +++ b/include/linux/ipc_namespace.h @@ -58,6 +58,7 @@ struct ipc_namespace { /* user_ns which owns the ipc ns */ struct user_namespace *user_ns; + struct ucounts *ucounts; struct ns_common ns; }; diff --git a/include/linux/user_namespace.h b/include/linux/user_namespace.h index f9df7dd2609a..e1d672186f00 100644 --- a/include/linux/user_namespace.h +++ b/include/linux/user_namespace.h @@ -28,6 +28,7 @@ enum ucount_type { UCOUNT_USER_NAMESPACES, UCOUNT_PID_NAMESPACES, UCOUNT_UTS_NAMESPACES, + UCOUNT_IPC_NAMESPACES, UCOUNT_COUNTS, }; 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); diff --git a/kernel/ucount.c b/kernel/ucount.c index 866850e2eb92..fbab75424da6 100644 --- a/kernel/ucount.c +++ b/kernel/ucount.c @@ -70,6 +70,7 @@ static struct ctl_table user_table[] = { UCOUNT_ENTRY("max_user_namespaces"), UCOUNT_ENTRY("max_pid_namespaces"), UCOUNT_ENTRY("max_uts_namespaces"), + UCOUNT_ENTRY("max_ipc_namespaces"), { } }; #endif /* CONFIG_SYSCTL */ |