Fix matching of long addresses. Bug 2677

[exim.git] / src / src / match.c

diff --git a/src/src/match.c b/src/src/match.c
index 6a331419422b8a06134206e7c46d4f3d6b4af35a..bf8cb3b98f8331700c187a9430ad8ebd9034b568 100644 (file)
--- a/src/src/match.c
+++ b/src/src/match.c
@@ -1269,9 +1269,11 @@ compared. Therefore, Exim now forces the entire address into lower case here,
 provided that "caseless" is set. (It is FALSE for calls for matching rewriting
 patterns.) Otherwise just the domain is lower cases. A magic item "+caseful" in
 the list can be used to restore a caseful copy of the local part from the
-original address. */
+original address.
+Limit the subject address size to avoid mem-exhastion attacks.  The size chosen
+is historical (we used to use big_buffer her). */
 
-if ((len = Ustrlen(address)) > 255) len = 255;
+if ((len = Ustrlen(address)) > BIG_BUFFER_SIZE) len = BIG_BUFFER_SIZE;
 ab.address = string_copyn(address, len);
 
 for (uschar * p = ab.address + len - 1; p >= ab.address; p--)