Protect sys-tuner socket access at create (#7230)

automerge

sys-tuner/Cargo.toml

@@ -12,6 +12,7 @@ publish = true
 [dependencies]
 clap = "2.33.0"
 log = "0.4.8"
+libc = "0.2.66"
 semver = "0.9.0"
 solana-logger = { path = "../logger", version = "0.22.0" }
 

sys-tuner/src/main.rs

@@ -56,6 +56,7 @@ fn tune_system() {
 #[cfg(unix)]
 fn main() {
     solana_logger::setup();
+    unsafe { libc::umask(0o077) };
     if let Err(e) = std::fs::remove_file(solana_sys_tuner::SOLANA_SYS_TUNER_PATH) {
         if e.kind() != std::io::ErrorKind::NotFound {
             panic!("Failed to remove stale socket file: {:?}", e)