From: Victor Julien <victor@inliniac.net>
Date: Tue, 2 Apr 2019 13:32:33 +0000 (+0200)
Subject: nfs: fix integer underflow
X-Git-Tag: suricata-5.0.0-beta1~1
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=63ab296cca7d2341b3ef587a3413e562c52cbee2;p=thirdparty%2Fsuricata.git

nfs: fix integer underflow

Fix int underflow that leads to Rust panic in NFS3 readdirplus
parsing.

Reported-by: Sirko Höer -- Code Intelligence for DCSO.
---

diff --git a/rust/src/nfs/nfs3.rs b/rust/src/nfs/nfs3.rs
index 3170d16a9e..96f1171fb4 100644
--- a/rust/src/nfs/nfs3.rs
+++ b/rust/src/nfs/nfs3.rs
@@ -286,7 +286,11 @@ impl NFSState {
                     nfs_status = reply.status;
 
                     // cut off final eof field
-                    let d = &reply.data[..reply.data.len()-4 as usize];
+                    let d = if reply.data.len() >= 4 {
+                        &reply.data[..reply.data.len()-4 as usize]
+                    } else {
+                        reply.data
+                    };
 
                     // store all handle/filename mappings
                     match many0_nfs3_response_readdirplus_entries(d) {