dovecot-2.1-pigeonhole: lib-sieve: Fixed code block read bounds ...

[pigeonhole at rename-it.nl]

details:   http://hg.rename-it.nl/dovecot-2.1-pigeonhole/rev/0ad4ca692650
changeset: 1696:0ad4ca692650
user:      Stephan Bosch <stephan at rename-it.nl>
date:      Sun Sep 15 17:47:53 2013 +0200
description:
lib-sieve: Fixed code block read bounds checking.

diffstat:

 src/lib-sieve/sieve-binary-code.c |  6 +++---
 1 files changed, 3 insertions(+), 3 deletions(-)

diffs (30 lines):

diff -r c20d078d0cf4 -r 0ad4ca692650 src/lib-sieve/sieve-binary-code.c
--- a/src/lib-sieve/sieve-binary-code.c	Sun Sep 15 12:19:10 2013 +0200
+++ b/src/lib-sieve/sieve-binary-code.c	Sun Sep 15 17:47:53 2013 +0200
@@ -214,7 +214,7 @@
 	((const int8_t *) (&_code[*address]))
 
 #define ADDR_BYTES_LEFT(address) \
-	((_code_size) - (*address))
+	((*address) > _code_size ? 0 : ((_code_size) - (*address)))
 #define ADDR_JUMP(address, offset) \
 	(*address) += offset
 
@@ -350,7 +350,7 @@
 
 	ADDR_CODE_READ(sblock);
 
-	if ( ADDR_BYTES_LEFT(address) <= 0 )
+	if ( ADDR_BYTES_LEFT(address) == 0 )
 		return FALSE;
 
 	(*offset_r) = code = ADDR_DATA_AT(address);
@@ -382,7 +382,7 @@
 	if ( objs->count == 1 )
 		return objs->objects;
 
-	if ( ADDR_BYTES_LEFT(address) <= 0 )
+	if ( ADDR_BYTES_LEFT(address) == 0 )
 		return NULL;
 
 	code = ADDR_DATA_AT(address);