xorg-wrapper: when starting the server as root, reset its environmentHEADmaster

When the server is privileged, we shouldn't be passing the user's
environment directly.

Clearing the environment is recommended by the libdbus maintainers, see
https://bugs.freedesktop.org/show_bug.cgi?id=52202

v2: rename envp to empty_envp (Jeremy)
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=83849
Signed-off-by: Julien Cristau <jcristau@debian.org>

1 files changed, 5 insertions, 1 deletions

diff --git a/hw/xfree86/xorg-wrapper.c b/hw/xfree86/xorg-wrapper.c
index 75d120ab6..6f658d7e2 100644
--- a/hw/xfree86/xorg-wrapper.c
+++ b/hw/xfree86/xorg-wrapper.c
@@ -194,6 +194,7 @@ int main(int argc, char *argv[])
     int total_cards = 0;
     int allowed = CONSOLE_ONLY;
     int needs_root_rights = -1;
+    char *const empty_envp[1] = { NULL, };
 
     progname = argv[0];
 
@@ -271,7 +272,10 @@ int main(int argc, char *argv[])
     }
 
     argv[0] = buf;
-    (void) execv(argv[0], argv);
+    if (getuid() == geteuid())
+        (void) execv(argv[0], argv);
+    else
+        (void) execve(argv[0], argv, empty_envp);
     fprintf(stderr, "%s: Failed to execute %s: %s\n",
         progname, buf, strerror(errno));
     exit(1);