From 74061958f56a4626a3a146c72f16e43012e828f1 Mon Sep 17 00:00:00 2001
From: Phil Sutter <psutter@redhat.com>
Date: Thu, 14 Sep 2017 15:39:23 +0200
Subject: [PATCH] netns: avoid directory traversal

Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1468529
Upstream Status: iproute2.git commit 79928fd0552b5

commit 79928fd0552b520aa36a22e71144d10a32f7e4fe
Author: Matteo Croce <mcroce@redhat.com>
Date:   Thu Jul 20 00:36:32 2017 +0200

    netns: avoid directory traversal

    ip netns keeps track of created namespaces with bind mounts named
    /var/run/netns/<namespace>. No input sanitization is done, allowing creation and
    deletion of files relatives to /var/run/netns or, if the path is non existent or
    invalid, allows to create "untracked" namespaces (invisible to the tool).

    This commit denies creation or deletion of namespaces with names contaning
    "/" or matching exactly "." or "..".

    Signed-off-by: Matteo Croce <mcroce@redhat.com>
---
 ip/ipnetns.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/ip/ipnetns.c b/ip/ipnetns.c
index 0b0378a..4254994 100644
--- a/ip/ipnetns.c
+++ b/ip/ipnetns.c
@@ -766,6 +766,11 @@ static int netns_monitor(int argc, char **argv)
 	return 0;
 }
 
+static int invalid_name(const char *name)
+{
+	return strchr(name, '/') || !strcmp(name, ".") || !strcmp(name, "..");
+}
+
 int do_netns(int argc, char **argv)
 {
 	netns_nsid_socket_init();
@@ -775,6 +780,11 @@ int do_netns(int argc, char **argv)
 		return netns_list(0, NULL);
 	}
 
+	if (argc > 1 && invalid_name(argv[1])) {
+		fprintf(stderr, "Invalid netns name \"%s\"\n", argv[1]);
+		exit(-1);
+	}
+
 	if ((matches(*argv, "list") == 0) || (matches(*argv, "show") == 0) ||
 	    (matches(*argv, "lst") == 0)) {
 		netns_map_init();
-- 
1.8.3.1