Avoid overlapping program header table with section header table NixO…

…S#457
brenoguim · Feb 18, 2023 · 9971836 · 9971836
1 parent 5908e16
commit 9971836
Showing 1 changed file with 8 additions and 2 deletions.
diff --git a/src/patchelf.cc b/src/patchelf.cc
@@ -749,8 +749,14 @@ void ElfFile<ElfFileParamNames>::rewriteSectionsLibrary()
        few segments to someplace else. */
     /* Some sections may already be replaced so account for that */
     unsigned int i = 1;
-    Elf_Addr pht_size = sizeof(Elf_Ehdr) + (phdrs.size() + num_notes + 1)*sizeof(Elf_Phdr);
-    while( i < rdi(hdr()->e_shnum) && rdi(shdrs.at(i).sh_offset) <= pht_size ) {
+    Elf_Addr firstFreeOffset = sizeof(Elf_Ehdr) + (phdrs.size() + num_notes + 1)*sizeof(Elf_Phdr);
+    if (rdi(hdr()->e_shoff) < firstFreeOffset) {
+        // The new program header table will overlap with the section header table.
+        // Put the section header table right after it, and account for its size.
+        wri(hdr()->e_shoff, firstFreeOffset);
+        firstFreeOffset += rdi(hdr()->e_shnum) * rdi(hdr()->e_shentsize);
+    }
+    while( i < rdi(hdr()->e_shnum) && rdi(shdrs.at(i).sh_offset) <= firstFreeOffset ) {
         if (not haveReplacedSection(getSectionName(shdrs.at(i))))
             replaceSection(getSectionName(shdrs.at(i)), rdi(shdrs.at(i).sh_size));
         i++;