From 815b73bdccae648f776ba98187f860fbdc1aa729 Mon Sep 17 00:00:00 2001
From: Andreas Kling <kling@serenityos.org>
Date: Tue, 14 Apr 2020 12:51:02 +0200
Subject: [PATCH] Kernel: Simplify sys$setgroups(0, ...)

If we're dropping all groups, just clear the extra_gids and return.
---
 Kernel/Process.cpp | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/Kernel/Process.cpp b/Kernel/Process.cpp
index c59029b902..0470e5f3fc 100644
--- a/Kernel/Process.cpp
+++ b/Kernel/Process.cpp
@@ -2727,6 +2727,11 @@ int Process::sys$setgroups(ssize_t count, const gid_t* user_gids)
     if (count && !validate_read(user_gids, count))
         return -EFAULT;
 
+    if (!count) {
+        m_extra_gids.clear();
+        return 0;
+    }
+
     Vector<gid_t> gids;
     gids.resize(count);
     copy_from_user(gids.data(), user_gids, sizeof(gid_t) * count);