From: Serge Hallyn Date: Sat, 11 Jan 2014 03:48:30 +0000 (-0600) Subject: Fix bug in preserve_ns X-Git-Tag: lxc-1.0.0.beta2~63 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=cd43d2d1b989f8ef292151d795c51e96df1cf903;p=thirdparty%2Flxc.git 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 Acked-by: Stéphane Graber --- diff --git a/src/lxc/start.c b/src/lxc/start.c index ce88d5f48..6c07e433f 100644 --- a/src/lxc/start.c +++ b/src/lxc/start.c @@ -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);