From 7917222486d0042a1800f25e12a9fa1f162c2eb0 Mon Sep 17 00:00:00 2001
From: Robert Swiecki <robert@swiecki.net>
Date: Wed, 21 Jun 2017 18:29:02 +0200
Subject: [PATCH] mount: Use /tmp/nsjail.[tmp|root].<orig_euid>

---
 cmdline.c | 1 +
 common.h  | 1 +
 mount.c   | 7 +++++--
 3 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/cmdline.c b/cmdline.c
index 5584662..458edf3 100644
--- a/cmdline.c
+++ b/cmdline.c
@@ -353,6 +353,7 @@ bool cmdlineParse(int argc, char *argv[], struct nsjconf_t * nsjconf)
       .iface_vs_gw = "0.0.0.0",
       .kafel_file = NULL,
       .kafel_string = NULL,
+      .orig_euid = geteuid(),
   };
   /*  *INDENT-ON* */
 
diff --git a/common.h b/common.h
index 62d78eb..f16c12d 100644
--- a/common.h
+++ b/common.h
@@ -164,6 +164,7 @@ struct nsjconf_t {
 	size_t cgroup_pids_max;
 	FILE *kafel_file;
 	char *kafel_string;
+	uid_t orig_euid;
 	 TAILQ_HEAD(udmaplist, idmap_t) uids;
 	 TAILQ_HEAD(gdmaplist, idmap_t) gids;
 	 TAILQ_HEAD(envlist, charptr_t) envs;
diff --git a/mount.c b/mount.c
index ba55951..296b50b 100644
--- a/mount.c
+++ b/mount.c
@@ -254,7 +254,8 @@ static bool mountInitNsInternal(struct nsjconf_t *nsjconf)
 		return false;
 	}
 
-	const char *const destdir = "/tmp/nsjail.root";
+	char destdir[PATH_MAX];
+	snprintf(destdir, sizeof(destdir), "/tmp/nsjail.root.%d", (int)nsjconf->orig_euid);
 	if (mkdir(destdir, 0755) == -1 && errno != EEXIST) {
 		PLOG_E("Couldn't create '%s' directory. Maybe remove it?", destdir);
 		return false;
@@ -263,7 +264,9 @@ static bool mountInitNsInternal(struct nsjconf_t *nsjconf)
 		PLOG_E("mount('%s', 'tmpfs')", destdir);
 		return false;
 	}
-	const char *const tmpdir = "/tmp/nsjail.tmp";
+
+	char tmpdir[PATH_MAX];
+	snprintf(tmpdir, sizeof(tmpdir), "/tmp/nsjail.tmp.%d", (int)nsjconf->orig_euid);
 	if (mkdir(tmpdir, 0755) == -1 && errno != EEXIST) {
 		PLOG_E("Couldn't create '%s' directory. Maybe remove it?", tmpdir);
 		return false;