Usually, PA will use the PULSE_SERVER X11 property instead of using XDG_RUNTIME_DIR, so this environment variable does not matter. If this property is not available, or if one is using the pacmd cli protocol, the client will go ahead and call pa_make_secure_dir on XDG_RUNTIME_DIR/pulse. This will either fail (if you're another regular user), or succeed (if you're root). Both scenarios are bad - failing will cause the connection to fail, and succeeding is even worse, as it can cause *other* connections to fail (as the directory ownership has changed). Instead fail and complain loudly. BugLink: https://bugs.freedesktop.org/show_bug.cgi?id=83007 Signed-off-by: David Henningsson <david.henningsson at canonical.com> --- src/pulsecore/core-util.c | 8 ++++++++ 1 file changed, 8 insertions(+) v2: Don't blame systemd anymore. Make error message translatable. diff --git a/src/pulsecore/core-util.c b/src/pulsecore/core-util.c index d7a95d6..6bb6317 100644 --- a/src/pulsecore/core-util.c +++ b/src/pulsecore/core-util.c @@ -1816,6 +1816,14 @@ char *pa_get_runtime_dir(void) { /* Use the XDG standard for the runtime directory. */ d = getenv("XDG_RUNTIME_DIR"); if (d) { + struct stat st; + if (stat(d, &st) == 0 && st.st_uid != getuid()) { + pa_log(_("XDG_RUNTIME_DIR (%s) is not owned by us (uid %d), but by uid %d!\n" + "(This could e g happen if you try to connect to a non-root PulseAudio as a root user, over the native protocol. Don't do that.)"), + d, getuid(), st.st_uid); + goto fail; + } + k = pa_sprintf_malloc("%s" PA_PATH_SEP "pulse", d); if (pa_make_secure_dir(k, m, (uid_t) -1, (gid_t) -1, true) < 0) { -- 1.9.1
