jail: call chdir(/) after pivot_root()

pivot_root(2) man page recommend calling chdir(/), so do it

Signed-off-by: Etienne CHAMPETIER <champetier.etienne@gmail.com>

diff --git a/jail/jail.c b/jail/jail.c
index 541363a..8157a8f 100644 (file)
--- a/jail/jail.c
+++ b/jail/jail.c
@@ -162,6 +162,10 @@ static int build_jail_fs(void)
                ERROR("pivot_root failed: %s\n", strerror(errno));
                return -1;
        }
+       if (chdir("/")) {
+               ERROR("chdir(/) failed: %s\n", strerror(errno));
+               return -1;
+       }
 
        snprintf(dirbuf, sizeof(dirbuf), "/old%s", jail_root);
        rmdir(dirbuf);