From 2f01b482586295071079a26ef64ec7d58ecdf8a2 Mon Sep 17 00:00:00 2001
From: NK <nicolas.devillers@airbus.com>
Date: Tue, 17 Mar 2026 02:16:51 +0100
Subject: [PATCH] Validate GPT entry size before allocation and slice access

Reject entry_size outside 128-4096 range to prevent:
- panic on slice &entry[0..16] when entry_size < 16
- OOM allocation from forged u32 entry_size
GPT spec mandates minimum 128 bytes per partition entry.
---
 src/sam/partition.rs | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/src/sam/partition.rs b/src/sam/partition.rs
index 0fd7575..e33a28d 100644
--- a/src/sam/partition.rs
+++ b/src/sam/partition.rs
@@ -82,6 +82,14 @@ fn find_gpt_ntfs_partitions<R: Read + Seek>(reader: &mut R) -> Result<Vec<u64>>
     let num_entries = crate::utils::read_u32_le(&hdr, 0x50).unwrap_or(0);
     let entry_size = crate::utils::read_u32_le(&hdr, 0x54).unwrap_or(0);
 
+    // GPT spec: entry_size is typically 128 bytes; reject invalid values
+    if !(128..=4096).contains(&entry_size) {
+        return Err(crate::error::VmkatzError::DecryptionError(format!(
+            "Invalid GPT entry size: {} (expected 128-4096)",
+            entry_size,
+        )));
+    }
+
     log::debug!(
         "GPT: entry_lba={}, num_entries={}, entry_size={}",
         entry_lba,