From: Martin Matuska <martin@matuska.org>
Date: Sat, 11 May 2019 00:36:53 +0000 (+0200)
Subject: RAR reader: fix use after free
X-Git-Tag: v3.4.0~32
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=b8592ecb;p=thirdparty%2Flibarchive.git

RAR reader: fix use after free

If read_data_compressed() returns ARCHIVE_FAILED, the caller is allowed
to continue with next archive headers. We need to set rar->start_new_table
after the ppmd7_context got freed, otherwise it won't be allocated again.

Reported by: OSS-Fuzz issue 2582
---

diff --git a/libarchive/archive_read_support_format_rar.c b/libarchive/archive_read_support_format_rar.c
index a8cc5c94d..49360876c 100644
--- a/libarchive/archive_read_support_format_rar.c
+++ b/libarchive/archive_read_support_format_rar.c
@@ -1024,8 +1024,10 @@ archive_read_format_rar_read_data(struct archive_read *a, const void **buff,
   case COMPRESS_METHOD_GOOD:
   case COMPRESS_METHOD_BEST:
     ret = read_data_compressed(a, buff, size, offset);
-    if (ret != ARCHIVE_OK && ret != ARCHIVE_WARN)
+    if (ret != ARCHIVE_OK && ret != ARCHIVE_WARN) {
       __archive_ppmd7_functions.Ppmd7_Free(&rar->ppmd7_context);
+      rar->start_new_table = 1;
+    }
     break;
 
   default: