grub2/0013-grub-core-lib-xzembed-xz_dec_stream.c-hash_validate-.patch

From 4942f9b133e52828d2441309beea0e9278e8b80c Mon Sep 17 00:00:00 2001
From: Vladimir 'phcoder' Serbinenko <phcoder@gmail.com>
Date: Sun, 22 Jul 2012 16:27:03 +0200
Subject: [PATCH 013/471] 	* grub-core/lib/xzembed/xz_dec_stream.c
 (hash_validate): Fix behaviour 	if hash function is unavailable. 
 (dec_stream_header): Likewise.

---
 ChangeLog                             |  6 ++++++
 grub-core/lib/xzembed/xz_dec_stream.c | 15 ++++++++++-----
 2 files changed, 16 insertions(+), 5 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 38374a3..892d31b 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,11 @@
 2012-07-22  Vladimir Serbinenko  <phcoder@gmail.com>
 
+	* grub-core/lib/xzembed/xz_dec_stream.c (hash_validate): Fix behaviour
+	if hash function is unavailable.
+	(dec_stream_header): Likewise.
+
+2012-07-22  Vladimir Serbinenko  <phcoder@gmail.com>
+
 	* grub-core/normal/autofs.c (autoload_fs_module): Save and restore
 	filter state.
 
diff --git a/grub-core/lib/xzembed/xz_dec_stream.c b/grub-core/lib/xzembed/xz_dec_stream.c
index 0d79b1f..6170b0c 100644
--- a/grub-core/lib/xzembed/xz_dec_stream.c
+++ b/grub-core/lib/xzembed/xz_dec_stream.c
@@ -403,18 +403,25 @@ static enum xz_ret hash_validate(struct xz_dec *s, struct xz_buf *b,
 	}
 #endif
 
-	do {
+	if (b->in_pos == b->in_size)
+		return XZ_OK;
+
+	if (!crc32 && s->hash_size == 0)
+		s->pos += 8;
+
+	while (s->pos < (crc32 ? 32 : s->hash_size * 8)) {
 		if (b->in_pos == b->in_size)
 			return XZ_OK;
 
 #ifndef GRUB_EMBED_DECOMPRESSOR
-		if (hash && s->hash_value[s->pos / 8] != b->in[b->in_pos++])
+		if (hash && s->hash_value[s->pos / 8] != b->in[b->in_pos])
 			return XZ_DATA_ERROR;
 #endif
+		b->in_pos++;
 
 		s->pos += 8;
 
-	} while (s->pos < (crc32 ? 32 : s->hash_size * 8));
+	}
 
 #ifndef GRUB_EMBED_DECOMPRESSOR
 	if (s->hash)
@@ -529,8 +536,6 @@ static enum xz_ret dec_stream_header(struct xz_dec *s)
 			s->hash->init(s->index.hash.hash_context);
  			s->hash->init(s->block.hash.hash_context);
 		}
-		if (!s->hash)
-			return XZ_OPTIONS_ERROR;
 #endif
 	}
 	else
-- 
1.8.2.1