From 592a65f52e7fa3076d6c5f5c15ef076103b82f95 Mon Sep 17 00:00:00 2001
From: Rob Bradford <robert.bradford@intel.com>
Date: Tue, 3 May 2022 16:34:02 +0100
Subject: [PATCH] qcow: Reject files with compressed blocks early

Fixes: #3727

Signed-off-by: Rob Bradford <robert.bradford@intel.com>
---
 qcow/src/qcow.rs | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/qcow/src/qcow.rs b/qcow/src/qcow.rs
index ac84de76e..ecbb49edb 100644
--- a/qcow/src/qcow.rs
+++ b/qcow/src/qcow.rs
@@ -516,6 +516,19 @@ impl QcowFile {
 
         let l2_entries = cluster_size / size_of::<u64>() as u64;
 
+        // Check for compressed blocks
+        for l2_addr_disk in l1_table.get_values() {
+            if *l2_addr_disk != 0 {
+                if let Err(e) = Self::read_l2_cluster(&mut raw_file, *l2_addr_disk) {
+                    if let Some(os_error) = e.raw_os_error() {
+                        if os_error == ENOTSUP {
+                            return Err(Error::CompressedBlocksNotSupported);
+                        }
+                    }
+                }
+            }
+        }
+
         let mut qcow = QcowFile {
             raw_file,
             header,