[llvm] [llvm][MachO] Fix integer truncation in rebase/bind parsing (PR #89337)
Zixu Wang via llvm-commits
llvm-commits at lists.llvm.org
Thu Apr 18 19:30:32 PDT 2024
https://github.com/zixu-w updated https://github.com/llvm/llvm-project/pull/89337
>From 0bedfe1fd2351954314e9af8a8a6e609deac731a Mon Sep 17 00:00:00 2001
From: Zixu Wang <zixu_wang at apple.com>
Date: Thu, 18 Apr 2024 18:08:48 -0700
Subject: [PATCH] [llvm][MachO] Fix integer truncation in rebase/bind parsing
`Count` and `Skip` should use `uint64_t` as they are encoded/decoded
using 64-bit ULEB128.
In *_OPCODE_DO_*_ULEB_TIMES_SKIPPING_ULEB`, `Skip` could be encoded as
a two's complement for moving `SegmentOffset` backwards. Having a 32-bit
`Skip` truncates the encoded value and leads to a malformed `AdvanceAmount`
and invalid `SegmentOffset` that extends past valid sections.
---
llvm/include/llvm/Object/MachO.h | 15 ++++++++-------
llvm/lib/Object/MachOObjectFile.cpp | 20 ++++++++++----------
2 files changed, 18 insertions(+), 17 deletions(-)
diff --git a/llvm/include/llvm/Object/MachO.h b/llvm/include/llvm/Object/MachO.h
index 24f9954584ed5d..35350df78f8d4e 100644
--- a/llvm/include/llvm/Object/MachO.h
+++ b/llvm/include/llvm/Object/MachO.h
@@ -134,9 +134,9 @@ class BindRebaseSegInfo {
BindRebaseSegInfo(const MachOObjectFile *Obj);
// Used to check a Mach-O Bind or Rebase entry for errors when iterating.
- const char* checkSegAndOffsets(int32_t SegIndex, uint64_t SegOffset,
- uint8_t PointerSize, uint32_t Count=1,
- uint32_t Skip=0);
+ const char *checkSegAndOffsets(int32_t SegIndex, uint64_t SegOffset,
+ uint8_t PointerSize, uint64_t Count = 1,
+ uint64_t Skip = 0);
// Used with valid SegIndex/SegOffset values from checked entries.
StringRef segmentName(int32_t SegIndex);
StringRef sectionName(int32_t SegIndex, uint64_t SegOffset);
@@ -576,8 +576,9 @@ class MachOObjectFile : public ObjectFile {
//
// This is used by MachOBindEntry::moveNext() to validate a MachOBindEntry.
const char *BindEntryCheckSegAndOffsets(int32_t SegIndex, uint64_t SegOffset,
- uint8_t PointerSize, uint32_t Count=1,
- uint32_t Skip=0) const {
+ uint8_t PointerSize,
+ uint64_t Count = 1,
+ uint64_t Skip = 0) const {
return BindRebaseSectionTable->checkSegAndOffsets(SegIndex, SegOffset,
PointerSize, Count, Skip);
}
@@ -591,8 +592,8 @@ class MachOObjectFile : public ObjectFile {
const char *RebaseEntryCheckSegAndOffsets(int32_t SegIndex,
uint64_t SegOffset,
uint8_t PointerSize,
- uint32_t Count=1,
- uint32_t Skip=0) const {
+ uint64_t Count = 1,
+ uint64_t Skip = 0) const {
return BindRebaseSectionTable->checkSegAndOffsets(SegIndex, SegOffset,
PointerSize, Count, Skip);
}
diff --git a/llvm/lib/Object/MachOObjectFile.cpp b/llvm/lib/Object/MachOObjectFile.cpp
index 1cfd0a069463e9..4f3b43be7c2074 100644
--- a/llvm/lib/Object/MachOObjectFile.cpp
+++ b/llvm/lib/Object/MachOObjectFile.cpp
@@ -3515,7 +3515,7 @@ void MachORebaseEntry::moveNext() {
uint8_t Byte = *Ptr++;
uint8_t ImmValue = Byte & MachO::REBASE_IMMEDIATE_MASK;
uint8_t Opcode = Byte & MachO::REBASE_OPCODE_MASK;
- uint32_t Count, Skip;
+ uint64_t Count, Skip;
const char *error = nullptr;
switch (Opcode) {
case MachO::REBASE_OPCODE_DONE:
@@ -3854,7 +3854,7 @@ void MachOBindEntry::moveNext() {
uint8_t Opcode = Byte & MachO::BIND_OPCODE_MASK;
int8_t SignExtended;
const uint8_t *SymStart;
- uint32_t Count, Skip;
+ uint64_t Count, Skip;
const char *error = nullptr;
switch (Opcode) {
case MachO::BIND_OPCODE_DONE:
@@ -4384,18 +4384,18 @@ BindRebaseSegInfo::BindRebaseSegInfo(const object::MachOObjectFile *Obj) {
// that fully contains a pointer at that location. Multiple fixups in a bind
// (such as with the BIND_OPCODE_DO_BIND_ULEB_TIMES_SKIPPING_ULEB opcode) can
// be tested via the Count and Skip parameters.
-const char * BindRebaseSegInfo::checkSegAndOffsets(int32_t SegIndex,
- uint64_t SegOffset,
- uint8_t PointerSize,
- uint32_t Count,
- uint32_t Skip) {
+const char *BindRebaseSegInfo::checkSegAndOffsets(int32_t SegIndex,
+ uint64_t SegOffset,
+ uint8_t PointerSize,
+ uint64_t Count,
+ uint64_t Skip) {
if (SegIndex == -1)
return "missing preceding *_OPCODE_SET_SEGMENT_AND_OFFSET_ULEB";
if (SegIndex >= MaxSegIndex)
return "bad segIndex (too large)";
- for (uint32_t i = 0; i < Count; ++i) {
- uint32_t Start = SegOffset + i * (PointerSize + Skip);
- uint32_t End = Start + PointerSize;
+ for (uint64_t i = 0; i < Count; ++i) {
+ uint64_t Start = SegOffset + i * (PointerSize + Skip);
+ uint64_t End = Start + PointerSize;
bool Found = false;
for (const SectionInfo &SI : Sections) {
if (SI.SegmentIndex != SegIndex)
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