First obtain correct number of sections, then read string table.

Fixes #89.
konrad-kruczynski · Nov 14, 2022 · 9ca7cf3 · 9ca7cf3
1 parent 4e1a6dd
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diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -5,6 +5,10 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [2.15.2] - 2022-11-14
+### Fixed
+- ELF: case when section number is larger than `SHN_LORESERVE` and string table is present is now handled properly.
+
 ## [2.15.1] - 2022-11-12
 ### Fixed
 - ELF: case when section number is larger than `SHN_LORESERVE` is now handled properly.

diff --git a/ELFSharp/ELF/ELF.cs b/ELFSharp/ELF/ELF.cs
@@ -228,15 +228,6 @@ private void ReadSections()
                 sectionIndicesByName = new Dictionary<string, int>();
             }
 
-            // If the number of sections is greater than or equal to SHN_LORESERVE (0xff00), this member has the
-            // value zero and the actual number of section header table entries is contained in the sh_size field
-            // of the section header at index 0. (Otherwise, the sh_size member of the initial entry contains 0.)
-            if (sectionHeaderEntryCount == 0)
-            {
-                var firstSectionHeader = ReadSectionHeader(0, true);
-                sectionHeaderEntryCount = checked((uint)firstSectionHeader.Size);
-            }
-
             for (var i = 0; i < sectionHeaderEntryCount; i++)
             {
                 var header = ReadSectionHeader(i);
@@ -370,6 +361,15 @@ private void ReadFields()
             sectionHeaderEntrySize = reader.ReadUInt16();
             sectionHeaderEntryCount = reader.ReadUInt16();
             stringTableIndex = reader.ReadUInt16();
+
+            // If the number of sections is greater than or equal to SHN_LORESERVE (0xff00), this member has the
+            // value zero and the actual number of section header table entries is contained in the sh_size field
+            // of the section header at index 0. (Otherwise, the sh_size member of the initial entry contains 0.)
+            if (sectionHeaderEntryCount == 0)
+            {
+                var firstSectionHeader = ReadSectionHeader(0, true);
+                sectionHeaderEntryCount = checked((uint)firstSectionHeader.Size);
+            }
         }
 
         private GetSectionResult TryGetSectionInner(string name, out Section<T> section)

diff --git a/ELFSharp/ELFSharp.csproj b/ELFSharp/ELFSharp.csproj
@@ -4,12 +4,12 @@
     <TargetFramework>netstandard2.0</TargetFramework>
     <SignAssembly>True</SignAssembly>
     <AssemblyOriginatorKeyFile>sgKey.snk</AssemblyOriginatorKeyFile>
-    <Version>2.15.1.0</Version>
+    <Version>2.15.2.0</Version>
     <AssemblyVersion>2.0</AssemblyVersion>
     <Authors>Konrad Kruczyński, Piotr Zierhoffer, Łukasz Kucharski, Bastian Eicher, Cameron, Everett Maus, Fox, Reuben Olinsky, Connor Christie, Rollrat, Ulysses Wu, Cédric Luthi, Yong Yan, Filip Navara, Dedmen Miller, Murat Ocaktürk</Authors>
     <Owners>Konrad Kruczyński</Owners>
     <PackageProjectUrl>http://elfsharp.it/</PackageProjectUrl>
-    <PackageReleaseNotes>Fixed bug when wrong ELF section numbers count is read. Detailed changelog available at: https://github.com/konrad-kruczynski/elfsharp/blob/master/CHANGELOG.md</PackageReleaseNotes>
+    <PackageReleaseNotes>Fixed bug with reading string table with large numbers of sections. Detailed changelog available at: https://github.com/konrad-kruczynski/elfsharp/blob/master/CHANGELOG.md</PackageReleaseNotes>
     <Summary>C# library for reading binary ELF, UImage, Mach-O files</Summary>
     <PackageTags>ELF UImage Mach-O</PackageTags>
     <Title>ELFSharp</Title>