From: Philippe Antoine <contact@catenacyber.fr>
Date: Sat, 2 Apr 2022 19:41:56 +0000 (+0200)
Subject: dcerpc: use wrappingadd for padding parsing
X-Git-Tag: suricata-6.0.6~70
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=5924869f5d1da46fe8bfda4d4eda124c15a79cde;p=thirdparty%2Fsuricata.git

dcerpc: use wrappingadd for padding parsing

As we compute a modulo, we can safely wrap around even if there
is an overflow

Ticket: #5301
(cherry picked from commit d2f00ac824068475414a6ee402c9ecf4b0de1308)
---

diff --git a/rust/src/dcerpc/parser.rs b/rust/src/dcerpc/parser.rs
index 9771a28be0..4110d03239 100644
--- a/rust/src/dcerpc/parser.rs
+++ b/rust/src/dcerpc/parser.rs
@@ -160,7 +160,7 @@ named!(pub parse_dcerpc_bindack<DCERPCBindAck>,
         >> _assoc_group: take!(4)
         >> sec_addr_len: le_u16
         >> take!(sec_addr_len)
-        >> cond!((sec_addr_len + 2) % 4 != 0, take!(4 - (sec_addr_len + 2) % 4))
+        >> cond!((sec_addr_len.wrapping_add(2)) % 4 != 0, take!(4 - (sec_addr_len.wrapping_add(2)) % 4))
         >> numctxitems: le_u8
         >> take!(3) // Padding
         >> ctxitems: count!(parse_dcerpc_bindack_result, numctxitems as usize)