From b526eed346f803665337b1e709c37458949964e6 Mon Sep 17 00:00:00 2001
From: John Reiser <jreiser@BitWagon.com>
Date: Wed, 23 Aug 2023 07:52:29 -0700
Subject: [PATCH] Detect "no Shdrs" earlier when already packed

https://github.com/upx/upx/issues/699
	modified:   p_lx_elf.cpp
---
 src/p_lx_elf.cpp | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/p_lx_elf.cpp b/src/p_lx_elf.cpp
index 4f547176..d0d0484f 100644
--- a/src/p_lx_elf.cpp
+++ b/src/p_lx_elf.cpp
@@ -1046,12 +1046,15 @@ PackLinuxElf64::PackLinuxElf64help1(InputFile *f)
         if (!(opt->cmd == CMD_COMPRESS && e_shoff < (upx_uint64_t)file_size && mb_shdr.getSize() == 0)) {
             shdri = nullptr;
         }
-        else {
+        else if (e_shnum && e_shoff && ehdri.e_shentsize) {
             fi->seek(e_shoff, SEEK_SET);
             mb_shdr.alloc(   sizeof(Elf64_Shdr) * e_shnum);
             shdri = (Elf64_Shdr *)mb_shdr.getVoidPtr();
             fi->readx(shdri, sizeof(Elf64_Shdr) * e_shnum);
         }
+        else {
+            shdri = nullptr;
+        }
         sec_dynsym = elf_find_section_type(Elf64_Shdr::SHT_DYNSYM);
         if (sec_dynsym) {
             unsigned t = get_te32(&sec_dynsym->sh_link);