From 688c05adf2783a4d434d73438d986053a9b85dd1 Mon Sep 17 00:00:00 2001
From: "google-labs-jules[bot]"
 <161369871+google-labs-jules[bot]@users.noreply.github.com>
Date: Mon, 5 Oct 2026 11:28:20 +0000
Subject: [PATCH] fix(security): limit info.json decompression size to prevent
 zip bomb DoS

Co-authored-by: TheDragonSoft <75906592+TheDragonSoft@users.noreply.github.com>
---
 src-tauri/src/core/services/downloader.rs |  4 +--
 src-tauri/src/core/services/mod_store.rs  | 33 ++++++++++++++++++++---
 2 files changed, 31 insertions(+), 6 deletions(-)

diff --git a/src-tauri/src/core/services/downloader.rs b/src-tauri/src/core/services/downloader.rs
index fc8b739..f3602a9 100644
--- a/src-tauri/src/core/services/downloader.rs
+++ b/src-tauri/src/core/services/downloader.rs
@@ -11,6 +11,7 @@ use tauri::{AppHandle, Emitter};
 use tokio::io::AsyncWriteExt;
 use tokio::sync::Semaphore;
 
+use crate::core::services::mod_store::read_entry_bounded;
 use crate::core::services::portal_client::{encode_path_component, plausible_name};
 use crate::error::AppError;
 use crate::models::{InstalledChangedPayload, InstalledChangedReason};
@@ -458,8 +459,7 @@ fn verify_mod_zip_sync(path: &Path, expected_name: &str, expected_version: &str)
             || entry_name.ends_with("\\info.json");
         if !entry.is_dir() && is_info_json {
             let name = entry_name.to_string();
-            let mut s = String::new();
-            std::io::Read::read_to_string(&mut entry, &mut s)
+            let s = read_entry_bounded(&mut entry)
                 .map_err(|e| AppError::Parse(format!("could not read info.json: {e}")))?;
             let is_root = name == "info.json";
             info_json = Some((name, s));
diff --git a/src-tauri/src/core/services/mod_store.rs b/src-tauri/src/core/services/mod_store.rs
index 340fee3..8a68728 100644
--- a/src-tauri/src/core/services/mod_store.rs
+++ b/src-tauri/src/core/services/mod_store.rs
@@ -18,6 +18,22 @@ use crate::models::{
 
 const MOD_LIST_FILE: &str = "mod-list.json";
 
+/// Maximum allowable decompressed size for an info.json entry (2 MiB).
+/// Protects against zip bomb / memory exhaustion DoS attacks during archive reading.
+pub const MAX_INFO_JSON_SIZE: u64 = 2 * 1024 * 1024;
+
+/// Read up to `MAX_INFO_JSON_SIZE` bytes from a zip entry into a String.
+pub fn read_entry_bounded<R: Read>(mut entry: R) -> Result<String, AppError> {
+    let mut s = String::new();
+    entry.by_ref().take(MAX_INFO_JSON_SIZE + 1).read_to_string(&mut s)?;
+    if s.len() > MAX_INFO_JSON_SIZE as usize {
+        return Err(AppError::Parse(format!(
+            "info.json exceeds maximum size limit of {MAX_INFO_JSON_SIZE} bytes"
+        )));
+    }
+    Ok(s)
+}
+
 // ---------------------------------------------------------------------------
 // Directory auto-detection (Phase 3)
 // ---------------------------------------------------------------------------
@@ -238,15 +254,13 @@ pub fn read_info_json(path: &Path) -> Result<InfoJson, AppError> {
         }
         let entry_name = entry.name().to_string();
         if entry_name == "info.json" || entry_name == "./info.json" {
-            let mut s = String::new();
-            entry.read_to_string(&mut s)?;
+            let s = read_entry_bounded(&mut entry)?;
             raw = Some(s);
             break;
         } else if nested.is_none()
             && (entry_name.ends_with("/info.json") || entry_name.ends_with("\\info.json"))
         {
-            let mut s = String::new();
-            entry.read_to_string(&mut s)?;
+            let s = read_entry_bounded(&mut entry)?;
             nested = Some(s);
         }
     }
@@ -1755,4 +1769,15 @@ mod tests {
 
         let _ = fs::remove_dir_all(&temp_dir);
     }
+
+    #[test]
+    fn test_oversized_info_json_rejected() {
+        let huge_data = vec![b'a'; (MAX_INFO_JSON_SIZE + 100) as usize];
+        let cursor = std::io::Cursor::new(huge_data);
+        let err = read_entry_bounded(cursor).unwrap_err();
+        assert!(
+            err.to_string().contains("exceeds maximum size limit"),
+            "expected size limit error, got: {err}"
+        );
+    }
 }