From 63ab296cca7d2341b3ef587a3413e562c52cbee2 Mon Sep 17 00:00:00 2001
From: Victor Julien <victor@inliniac.net>
Date: Tue, 2 Apr 2019 15:32:33 +0200
Subject: [PATCH] nfs: fix integer underflow
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Fix int underflow that leads to Rust panic in NFS3 readdirplus
parsing.

Reported-by: Sirko Höer -- Code Intelligence for DCSO.
---
 rust/src/nfs/nfs3.rs | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

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) {
-- 
2.47.3