I ran across this while auditing gvisor for 4.4 compatiblity. The source comment says:
// TODO(b/27454212): Consider supporting disabling setgroups(2), which "was
// added in Linux 3.19, but was backported to many earlier stable kernel
// series, because it addresses a security issue" - user_namespaces(7). (It
// was not backported to 3.11.10, which we are currently imitating.)
Since we're moving up to 4.4 now, this is now in scope of our emulated version.
I ran across this while auditing gvisor for 4.4 compatiblity. The source comment says:
Since we're moving up to 4.4 now, this is now in scope of our emulated version.