Fix bug in preserve_ns

If /proc/self/ns does not exist, then preserve_ns was failing to
initialize the saved_ns[i] to -1.  This caused attach_ns() to try
and attach, and of course fail.

Initialize the saved ns values before returning an error.

The return values of preserve_ns and attach_ns were also being
ignored.  Honor them.

Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>
Acked-by: Stéphane Graber <stgraber@ubuntu.com>
This commit is contained in:
Serge Hallyn 2014-01-10 21:48:30 -06:00 committed by Stéphane Graber
parent dad87e3bd1
commit cd43d2d1b9

View File

@ -98,14 +98,14 @@ static int preserve_ns(int ns_fd[LXC_NS_MAX], int clone_flags) {
int i, saved_errno;
char path[MAXPATHLEN];
if (access("/proc/self/ns", X_OK)) {
ERROR("Does this kernel version support 'attach'?");
return -1;
}
for (i = 0; i < LXC_NS_MAX; i++)
ns_fd[i] = -1;
if (access("/proc/self/ns", X_OK)) {
WARN("Kernel does not support attach; preserve_ns ignored");
return 0;
}
for (i = 0; i < LXC_NS_MAX; i++) {
if ((clone_flags & ns_info[i].clone_flag) == 0)
continue;
@ -788,8 +788,10 @@ static int lxc_spawn(struct lxc_handler *handler)
if (handler->pinfd == -1)
INFO("failed to pin the container's rootfs");
preserve_ns(saved_ns_fd, preserve_mask);
attach_ns(handler->conf->inherit_ns_fd);
if (preserve_ns(saved_ns_fd, preserve_mask) < 0)
goto out_delete_net;
if (attach_ns(handler->conf->inherit_ns_fd) < 0)
goto out_delete_net;
/* Create a process in a new set of namespaces */
handler->pid = lxc_clone(do_start, handler, handler->clone_flags);
@ -798,7 +800,8 @@ static int lxc_spawn(struct lxc_handler *handler)
goto out_delete_net;
}
attach_ns(saved_ns_fd);
if (attach_ns(saved_ns_fd))
WARN("failed to restore saved namespaces");
lxc_sync_fini_child(handler);