From 5ac09433262095470f39fc5ea318ea9411923a06 Mon Sep 17 00:00:00 2001
From: Dominik George <dominik.george@teckids.org>
Date: Tue, 11 May 2021 20:02:52 +0200
Subject: [PATCH] Fix NullPointerException for getpwnam/getuid structs on
unknown users
---
src/cache.rs | 10 +++++++++-
src/nss.rs | 13 +++++++++++--
2 files changed, 20 insertions(+), 3 deletions(-)
diff --git a/src/cache.rs b/src/cache.rs
index f5fa9d9..040ec37 100644
--- a/src/cache.rs
+++ b/src/cache.rs
@@ -63,9 +63,17 @@ impl Cache {
Ok(nam) => nam,
Err(_) => return Err("Invalid username in lookup")
};
+ let pw;
+ unsafe {
+ pw = getpwnam(nam.as_ptr());
+ };
+ if pw.is_null() {
+ error!("Failed to lookup user {}", username);
+ return Err("Failed to lookup user");
+ }
let target_euid;
unsafe {
- target_euid = (*getpwnam(nam.as_ptr())).pw_uid;
+ target_euid = (*pw).pw_uid;
};
if target_euid == current_euid {
diff --git a/src/nss.rs b/src/nss.rs
index 9d76fce..9588e03 100644
--- a/src/nss.rs
+++ b/src/nss.rs
@@ -59,10 +59,19 @@ fn nss_hook_prepare() -> Config {
fn get_current_user() -> String {
let euid;
- let euser;
+ let pw;
unsafe {
euid = geteuid();
- euser = CStr::from_ptr((*getpwuid(euid)).pw_name);
+ pw = getpwuid(euid);
+ };
+ if pw.is_null() {
+ error!("Failed to look up user name for UID {}", euid);
+ return "nobody".to_string();
+ }
+
+ let euser;
+ unsafe {
+ euser = CStr::from_ptr((*pw).pw_name);
};
euser.to_str().ok().unwrap().to_string()
}
--
GitLab