From 9dfc8f573c44c5ba3993a53f926655091d799206 Mon Sep 17 00:00:00 2001
From: John Reiser <jreiser@BitWagon.com>
Date: Thu, 23 Jul 2020 05:44:18 -0700
Subject: [PATCH] Avoid 0==nbucket

https://github.com/upx/upx/issues/393
	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 d7d14426..0fec6066 100644
--- a/src/p_lx_elf.cpp
+++ b/src/p_lx_elf.cpp
@@ -5415,7 +5415,6 @@ Elf32_Sym const *PackLinuxElf32::elf_lookup(char const *name) const
         unsigned const nbucket = get_te32(&hashtab[0]);
         unsigned const *const buckets = &hashtab[2];
         unsigned const *const chains = &buckets[nbucket];
-        unsigned const m = elf_hash(name) % nbucket;
         if (!nbucket
         ||  (unsigned)(file_size - ((char const *)buckets - (char const *)(void const *)file_image))
                 <= sizeof(unsigned)*nbucket ) {
@@ -5423,6 +5422,7 @@ Elf32_Sym const *PackLinuxElf32::elf_lookup(char const *name) const
                 "bad nbucket %#x\n", nbucket);
             throwCantPack(msg);
         }
+        unsigned const m = elf_hash(name) % nbucket;
         unsigned si;
         for (si= get_te32(&buckets[m]); 0!=si; si= get_te32(&chains[si])) {
             char const *const p= get_dynsym_name(si, (unsigned)-1);
@@ -5492,7 +5492,6 @@ Elf64_Sym const *PackLinuxElf64::elf_lookup(char const *name) const
         unsigned const nbucket = get_te32(&hashtab[0]);
         unsigned const *const buckets = &hashtab[2];
         unsigned const *const chains = &buckets[nbucket];
-        unsigned const m = elf_hash(name) % nbucket;
         if (!nbucket
         ||  (unsigned)(file_size - ((char const *)buckets - (char const *)(void const *)file_image))
                 <= sizeof(unsigned)*nbucket ) {
@@ -5500,6 +5499,7 @@ Elf64_Sym const *PackLinuxElf64::elf_lookup(char const *name) const
                 "bad nbucket %#x\n", nbucket);
             throwCantPack(msg);
         }
+        unsigned const m = elf_hash(name) % nbucket;
         unsigned si;
         for (si= get_te32(&buckets[m]); 0!=si; si= get_te32(&chains[si])) {
             char const *const p= get_dynsym_name(si, (unsigned)-1);