From 0e6cef99a009d6864b5fef6d7931f83c49fe5d12 Mon Sep 17 00:00:00 2001
From: John Reiser <jreiser@BitWagon.com>
Date: Wed, 1 May 2024 10:09:52 -0700
Subject: [PATCH] Guard against empty PT_NOTE

https://github.com/upx/upx/issues/817
	modified:   p_lx_elf.cpp
---
 src/p_lx_elf.cpp | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/p_lx_elf.cpp b/src/p_lx_elf.cpp
index 71ce6dbc..9855805c 100644
--- a/src/p_lx_elf.cpp
+++ b/src/p_lx_elf.cpp
@@ -3984,8 +3984,8 @@ void PackLinuxElf32::pack1(OutputFile * /*fo*/, Filter &ft)
     phdr = phdri;
     for (unsigned j=0; j < e_phnum; ++phdr, ++j) {
         unsigned const type = get_te32(&phdr->p_type);
-        if (PT_NOTE32 == type) {
-            unsigned const len = get_te32(&phdr->p_filesz);
+        unsigned const len = get_te32(&phdr->p_filesz);
+        if (PT_NOTE32 == type && len && note_body.getSize()) {
             fi->seek(get_te32(&phdr->p_offset), SEEK_SET);
             fi->readx(&note_body[note_size], len);
             note_size += up4(len);