Fix ordering of setgid and setuid

It looks like the code to drop privileges may have been broken via
commit 37f0e1f. That commit reverted the correct order from #911, which
first drops the gid then the uid. If setuid is called first then the
target user may not have the ability to setgid.
This commit is contained in:
Teddy Reed 2020-02-10 21:29:26 -05:00 committed by Simon Ser
parent 0b709702c1
commit 31a83bd48d

View file

@ -186,12 +186,17 @@ static void log_kernel(void) {
static bool drop_permissions(void) {
if (getuid() != geteuid() || getgid() != getegid()) {
if (setuid(getuid()) != 0 || setgid(getgid()) != 0) {
sway_log(SWAY_ERROR, "Unable to drop root, refusing to start");
// Set the gid and uid in the correct order.
if (setgid(getgid()) != 0) {
sway_log(SWAY_ERROR, "Unable to drop root group, refusing to start");
return false;
}
if (setuid(getuid()) != 0) {
sway_log(SWAY_ERROR, "Unable to drop root user, refusing to start");
return false;
}
}
if (setuid(0) != -1) {
if (setgid(0) != -1 || setuid(0) != -1) {
sway_log(SWAY_ERROR, "Unable to drop root (we shouldn't be able to "
"restore it after setuid), refusing to start");
return false;