From 17d9d73ee92eeb1a08b0a56659d010d8120af33a Mon Sep 17 00:00:00 2001
From: Wei-Cheng Pan <legnaleurc@gmail.com>
Date: Fri, 26 Apr 2024 13:58:34 +0900
Subject: [PATCH] fix: OOB in rar delta filter

---
 libarchive/archive_read_support_format_rar.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/libarchive/archive_read_support_format_rar.c b/libarchive/archive_read_support_format_rar.c
index 79669a8f4..619ee81e2 100644
--- a/libarchive/archive_read_support_format_rar.c
+++ b/libarchive/archive_read_support_format_rar.c
@@ -3612,7 +3612,15 @@ execute_filter_delta(struct rar_filter *filter, struct rar_virtual_machine *vm)
   {
     uint8_t lastbyte = 0;
     for (idx = i; idx < length; idx += numchannels)
+    {
+      /*
+       * The src block should not overlap with the dst block.
+       * If so it would be better to consider this archive is broken.
+       */
+      if (src >= dst)
+        return 0;
       lastbyte = dst[idx] = lastbyte - *src++;
+    }
   }
 
   filter->filteredblockaddress = length;