[lld] 68f5a8b - [DebugInfo] Do not hang when parsing a malformed .debug_pub* section.
Igor Kudrin via llvm-commits
llvm-commits at lists.llvm.org
Thu Jul 9 05:16:45 PDT 2020
Author: Igor Kudrin
Date: 2020-07-09T19:15:11+07:00
New Revision: 68f5a8b2042b8c4dc83d1851b462a0570eb3410f
URL: https://github.com/llvm/llvm-project/commit/68f5a8b2042b8c4dc83d1851b462a0570eb3410f
DIFF: https://github.com/llvm/llvm-project/commit/68f5a8b2042b8c4dc83d1851b462a0570eb3410f.diff
LOG: [DebugInfo] Do not hang when parsing a malformed .debug_pub* section.
The parsing method did not check reading errors and might easily fall
into an infinite loop on an invalid input because of that.
Differential Revision: https://reviews.llvm.org/D83049
Added:
lld/test/ELF/gdb-index-invalid-pubnames.s
llvm/test/tools/llvm-dwarfdump/X86/debug_pub_tables_invalid.s
Modified:
lld/ELF/DWARF.h
lld/ELF/SyntheticSections.cpp
llvm/include/llvm/DebugInfo/DWARF/DWARFDebugPubTable.h
llvm/lib/DebugInfo/DWARF/DWARFContext.cpp
llvm/lib/DebugInfo/DWARF/DWARFDebugPubTable.cpp
Removed:
################################################################################
diff --git a/lld/ELF/DWARF.h b/lld/ELF/DWARF.h
index 8609e35faf95..a12dae6e9960 100644
--- a/lld/ELF/DWARF.h
+++ b/lld/ELF/DWARF.h
@@ -56,11 +56,11 @@ template <class ELFT> class LLDDwarfObj final : public llvm::DWARFObject {
return addrSection;
}
- const llvm::DWARFSection &getGnuPubnamesSection() const override {
+ const LLDDWARFSection &getGnuPubnamesSection() const override {
return gnuPubnamesSection;
}
- const llvm::DWARFSection &getGnuPubtypesSection() const override {
+ const LLDDWARFSection &getGnuPubtypesSection() const override {
return gnuPubtypesSection;
}
diff --git a/lld/ELF/SyntheticSections.cpp b/lld/ELF/SyntheticSections.cpp
index f6d66fff6d4b..33748f881576 100644
--- a/lld/ELF/SyntheticSections.cpp
+++ b/lld/ELF/SyntheticSections.cpp
@@ -2705,12 +2705,15 @@ template <class ELFT>
static std::vector<GdbIndexSection::NameAttrEntry>
readPubNamesAndTypes(const LLDDwarfObj<ELFT> &obj,
const std::vector<GdbIndexSection::CuEntry> &cus) {
- const DWARFSection &pubNames = obj.getGnuPubnamesSection();
- const DWARFSection &pubTypes = obj.getGnuPubtypesSection();
+ const LLDDWARFSection &pubNames = obj.getGnuPubnamesSection();
+ const LLDDWARFSection &pubTypes = obj.getGnuPubtypesSection();
std::vector<GdbIndexSection::NameAttrEntry> ret;
- for (const DWARFSection *pub : {&pubNames, &pubTypes}) {
- DWARFDebugPubTable table(obj, *pub, config->isLE, true);
+ for (const LLDDWARFSection *pub : {&pubNames, &pubTypes}) {
+ DWARFDataExtractor data(obj, *pub, config->isLE, config->wordsize);
+ DWARFDebugPubTable table;
+ if (Error e = table.extract(data, /*GnuStyle=*/true))
+ warn(toString(pub->sec) + ": " + toString(std::move(e)));
for (const DWARFDebugPubTable::Set &set : table.getData()) {
// The value written into the constant pool is kind << 24 | cuIndex. As we
// don't know how many compilation units precede this object to compute
diff --git a/lld/test/ELF/gdb-index-invalid-pubnames.s b/lld/test/ELF/gdb-index-invalid-pubnames.s
new file mode 100644
index 000000000000..15eb86ee7c1e
--- /dev/null
+++ b/lld/test/ELF/gdb-index-invalid-pubnames.s
@@ -0,0 +1,26 @@
+# REQUIRES: x86
+# RUN: llvm-mc -filetype=obj -triple=x86_64 %s -o %t
+# RUN: ld.lld --gdb-index %t -o /dev/null 2>&1 | FileCheck %s
+
+# CHECK: warning: {{.*}}(.debug_gnu_pubnames): unexpected end of data at offset 0x1 while reading [0x0, 0x4)
+
+ .section .debug_abbrev,"", at progbits
+ .byte 1 # Abbreviation Code
+ .byte 17 # DW_TAG_compile_unit
+ .byte 0 # DW_CHILDREN_no
+ .byte 0 # EOM(1)
+ .byte 0 # EOM(2)
+ .byte 0 # EOM(3)
+
+ .section .debug_info,"", at progbits
+.LCUBegin:
+ .long .LUnitEnd-.LUnitBegin # Length of Unit
+.LUnitBegin:
+ .short 4 # DWARF version number
+ .long .debug_abbrev # Offset Into Abbrev. Section
+ .byte 8 # Address Size (in bytes)
+ .byte 1 # Abbrev [1] DW_TAG_compile_unit
+.LUnitEnd:
+
+ .section .debug_gnu_pubnames,"", at progbits
+ .byte 0
diff --git a/llvm/include/llvm/DebugInfo/DWARF/DWARFDebugPubTable.h b/llvm/include/llvm/DebugInfo/DWARF/DWARFDebugPubTable.h
index 60f80bb12aa9..80c2d75bdc2a 100644
--- a/llvm/include/llvm/DebugInfo/DWARF/DWARFDebugPubTable.h
+++ b/llvm/include/llvm/DebugInfo/DWARF/DWARFDebugPubTable.h
@@ -12,6 +12,7 @@
#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/BinaryFormat/Dwarf.h"
+#include "llvm/DebugInfo/DWARF/DWARFDataExtractor.h"
#include "llvm/DebugInfo/DWARF/DWARFObject.h"
#include <cstdint>
#include <vector>
@@ -67,11 +68,12 @@ class DWARFDebugPubTable {
/// gnu styled tables contains additional information.
/// This flag determines whether or not section we parse is debug_gnu* table.
- bool GnuStyle;
+ bool GnuStyle = false;
public:
- DWARFDebugPubTable(const DWARFObject &Obj, const DWARFSection &Sec,
- bool LittleEndian, bool GnuStyle);
+ DWARFDebugPubTable() = default;
+
+ Error extract(DWARFDataExtractor Data, bool GnuStyle);
void dump(raw_ostream &OS) const;
diff --git a/llvm/lib/DebugInfo/DWARF/DWARFContext.cpp b/llvm/lib/DebugInfo/DWARF/DWARFContext.cpp
index ebe2600e0689..dba6b85e9104 100644
--- a/llvm/lib/DebugInfo/DWARF/DWARFContext.cpp
+++ b/llvm/lib/DebugInfo/DWARF/DWARFContext.cpp
@@ -336,6 +336,14 @@ static void dumpLoclistsSection(raw_ostream &OS, DIDumpOptions DumpOpts,
}
}
+static void dumpPubTableSection(raw_ostream &OS, DIDumpOptions DumpOpts,
+ DWARFDataExtractor Data, bool GnuStyle) {
+ DWARFDebugPubTable Table;
+ if (Error E = Table.extract(Data, GnuStyle))
+ DumpOpts.RecoverableErrorHandler(std::move(E));
+ Table.dump(OS);
+}
+
void DWARFContext::dump(
raw_ostream &OS, DIDumpOptions DumpOpts,
std::array<Optional<uint64_t>, DIDT_ID_Count> DumpOffsets) {
@@ -626,26 +634,32 @@ void DWARFContext::dump(
}
if (shouldDump(Explicit, ".debug_pubnames", DIDT_ID_DebugPubnames,
- DObj->getPubnamesSection().Data))
- DWARFDebugPubTable(*DObj, DObj->getPubnamesSection(), isLittleEndian(), false)
- .dump(OS);
+ DObj->getPubnamesSection().Data)) {
+ DWARFDataExtractor PubTableData(*DObj, DObj->getPubnamesSection(),
+ isLittleEndian(), 0);
+ dumpPubTableSection(OS, DumpOpts, PubTableData, /*GnuStyle=*/false);
+ }
if (shouldDump(Explicit, ".debug_pubtypes", DIDT_ID_DebugPubtypes,
- DObj->getPubtypesSection().Data))
- DWARFDebugPubTable(*DObj, DObj->getPubtypesSection(), isLittleEndian(), false)
- .dump(OS);
+ DObj->getPubtypesSection().Data)) {
+ DWARFDataExtractor PubTableData(*DObj, DObj->getPubtypesSection(),
+ isLittleEndian(), 0);
+ dumpPubTableSection(OS, DumpOpts, PubTableData, /*GnuStyle=*/false);
+ }
if (shouldDump(Explicit, ".debug_gnu_pubnames", DIDT_ID_DebugGnuPubnames,
- DObj->getGnuPubnamesSection().Data))
- DWARFDebugPubTable(*DObj, DObj->getGnuPubnamesSection(), isLittleEndian(),
- true /* GnuStyle */)
- .dump(OS);
+ DObj->getGnuPubnamesSection().Data)) {
+ DWARFDataExtractor PubTableData(*DObj, DObj->getGnuPubnamesSection(),
+ isLittleEndian(), 0);
+ dumpPubTableSection(OS, DumpOpts, PubTableData, /*GnuStyle=*/true);
+ }
if (shouldDump(Explicit, ".debug_gnu_pubtypes", DIDT_ID_DebugGnuPubtypes,
- DObj->getGnuPubtypesSection().Data))
- DWARFDebugPubTable(*DObj, DObj->getGnuPubtypesSection(), isLittleEndian(),
- true /* GnuStyle */)
- .dump(OS);
+ DObj->getGnuPubtypesSection().Data)) {
+ DWARFDataExtractor PubTableData(*DObj, DObj->getGnuPubtypesSection(),
+ isLittleEndian(), 0);
+ dumpPubTableSection(OS, DumpOpts, PubTableData, /*GnuStyle=*/true);
+ }
if (shouldDump(Explicit, ".debug_str_offsets", DIDT_ID_DebugStrOffsets,
DObj->getStrOffsetsSection().Data))
diff --git a/llvm/lib/DebugInfo/DWARF/DWARFDebugPubTable.cpp b/llvm/lib/DebugInfo/DWARF/DWARFDebugPubTable.cpp
index eecca87d5270..45e16653420c 100644
--- a/llvm/lib/DebugInfo/DWARF/DWARFDebugPubTable.cpp
+++ b/llvm/lib/DebugInfo/DWARF/DWARFDebugPubTable.cpp
@@ -18,34 +18,32 @@
using namespace llvm;
using namespace dwarf;
-DWARFDebugPubTable::DWARFDebugPubTable(const DWARFObject &Obj,
- const DWARFSection &Sec,
- bool LittleEndian, bool GnuStyle)
- : GnuStyle(GnuStyle) {
- DWARFDataExtractor PubNames(Obj, Sec, LittleEndian, 0);
- uint64_t Offset = 0;
- while (PubNames.isValidOffset(Offset)) {
+Error DWARFDebugPubTable::extract(DWARFDataExtractor Data, bool GnuStyle) {
+ this->GnuStyle = GnuStyle;
+ Sets.clear();
+ DataExtractor::Cursor C(0);
+ while (C && Data.isValidOffset(C.tell())) {
Sets.push_back({});
Set &SetData = Sets.back();
- std::tie(SetData.Length, SetData.Format) =
- PubNames.getInitialLength(&Offset);
+ std::tie(SetData.Length, SetData.Format) = Data.getInitialLength(C);
const unsigned OffsetSize = dwarf::getDwarfOffsetByteSize(SetData.Format);
- SetData.Version = PubNames.getU16(&Offset);
- SetData.Offset = PubNames.getRelocatedValue(OffsetSize, &Offset);
- SetData.Size = PubNames.getUnsigned(&Offset, OffsetSize);
+ SetData.Version = Data.getU16(C);
+ SetData.Offset = Data.getRelocatedValue(C, OffsetSize);
+ SetData.Size = Data.getUnsigned(C, OffsetSize);
- while (Offset < Sec.Data.size()) {
- uint64_t DieRef = PubNames.getUnsigned(&Offset, OffsetSize);
+ while (C) {
+ uint64_t DieRef = Data.getUnsigned(C, OffsetSize);
if (DieRef == 0)
break;
- uint8_t IndexEntryValue = GnuStyle ? PubNames.getU8(&Offset) : 0;
- StringRef Name = PubNames.getCStrRef(&Offset);
+ uint8_t IndexEntryValue = GnuStyle ? Data.getU8(C) : 0;
+ StringRef Name = Data.getCStrRef(C);
SetData.Entries.push_back(
{DieRef, PubIndexEntryDescriptor(IndexEntryValue), Name});
}
}
+ return C.takeError();
}
void DWARFDebugPubTable::dump(raw_ostream &OS) const {
diff --git a/llvm/test/tools/llvm-dwarfdump/X86/debug_pub_tables_invalid.s b/llvm/test/tools/llvm-dwarfdump/X86/debug_pub_tables_invalid.s
new file mode 100644
index 000000000000..cfd75c2a9aca
--- /dev/null
+++ b/llvm/test/tools/llvm-dwarfdump/X86/debug_pub_tables_invalid.s
@@ -0,0 +1,26 @@
+# RUN: llvm-mc -triple x86_64 %s -filetype=obj -o %t
+# RUN: not llvm-dwarfdump -v %t 2>&1 | FileCheck %s
+
+# CHECK: .debug_pubnames contents:
+# CHECK-NEXT: error: unexpected end of data at offset 0x1 while reading [0x0, 0x4)
+
+# CHECK: .debug_pubtypes contents:
+# CHECK-NEXT: error: unexpected end of data at offset 0x1 while reading [0x0, 0x4)
+
+# CHECK: .debug_gnu_pubnames contents:
+# CHECK-NEXT: error: unexpected end of data at offset 0x1 while reading [0x0, 0x4)
+
+# CHECK: .debug_gnu_pubtypes contents:
+# CHECK-NEXT: error: unexpected end of data at offset 0x1 while reading [0x0, 0x4)
+
+ .section .debug_pubnames,"", at progbits
+ .byte 0
+
+ .section .debug_pubtypes,"", at progbits
+ .byte 0
+
+ .section .debug_gnu_pubnames,"", at progbits
+ .byte 0
+
+ .section .debug_gnu_pubtypes,"", at progbits
+ .byte 0
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