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PECOFF: Fix section name computation

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If a section name is exactly 8 bytes long (or has been truncated to 8
bytes), it will not contain the terminating nul character. This means
reading the name as a c string will pick up random data following the
name field (which happens to be the section vm size).

This fixes the name computation to avoid out-of-bounds access and adds a
test.

Reviewers: zturner, stella.stamenova

Subscribers: lldb-commits

Differential Revision: https://reviews.llvm.org/D56124

llvm-svn: 350809
This commit is contained in:
Pavel Labath
2019-01-10 10:23:19 +00:00
parent b7871405fa
commit 2886e4a081
3 changed files with 66 additions and 19 deletions
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31
lldb/source/Plugins/ObjectFile/PECOFF/ObjectFilePECOFF.cpp
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@@ -530,22 +530,20 @@ bool ObjectFilePECOFF::ParseSectionHeaders(
return !m_sect_headers.empty();
}
bool ObjectFilePECOFF::GetSectionName(std::string &sect_name,
const section_header_t &sect) {
if (sect.name[0] == '/') {
lldb::offset_t stroff = strtoul(&sect.name[1], NULL, 10);
llvm::StringRef ObjectFilePECOFF::GetSectionName(const section_header_t &sect) {
llvm::StringRef hdr_name(sect.name, llvm::array_lengthof(sect.name));
hdr_name = hdr_name.split('\0').first;
if (hdr_name.consume_front("/")) {
lldb::offset_t stroff;
if (!to_integer(hdr_name, stroff, 10))
return "";
lldb::offset_t string_file_offset =
m_coff_header.symoff + (m_coff_header.nsyms * 18) + stroff;
const char *name = m_data.GetCStr(&string_file_offset);
if (name) {
sect_name = name;
return true;
}
return false;
if (const char *name = m_data.GetCStr(&string_file_offset))
return name;
return "";
}
sect_name = sect.name;
return true;
return hdr_name;
}
//----------------------------------------------------------------------
@@ -712,9 +710,7 @@ void ObjectFilePECOFF::CreateSections(SectionList &unified_section_list) {
const uint32_t nsects = m_sect_headers.size();
ModuleSP module_sp(GetModule());
for (uint32_t idx = 0; idx < nsects; ++idx) {
std::string sect_name;
GetSectionName(sect_name, m_sect_headers[idx]);
ConstString const_sect_name(sect_name.c_str());
ConstString const_sect_name(GetSectionName(m_sect_headers[idx]));
static ConstString g_code_sect_name(".code");
static ConstString g_CODE_sect_name("CODE");
static ConstString g_data_sect_name(".data");
@@ -1086,8 +1082,7 @@ void ObjectFilePECOFF::DumpOptCOFFHeader(Stream *s,
//----------------------------------------------------------------------
void ObjectFilePECOFF::DumpSectionHeader(Stream *s,
const section_header_t &sh) {
std::string name;
GetSectionName(name, sh);
std::string name = GetSectionName(sh);
s->Printf("%-16s 0x%8.8x 0x%8.8x 0x%8.8x 0x%8.8x 0x%8.8x 0x%8.8x 0x%4.4x "
"0x%4.4x 0x%8.8x\n",
name.c_str(), sh.vmaddr, sh.vmsize, sh.offset, sh.size, sh.reloff,