Skip to content

debug/elf: prevent offset overflow #75522

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
wants to merge 1 commit into
base: master
Choose a base branch
from
Open

debug/elf: prevent offset overflow #75522

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
125 changes: 82 additions & 43 deletions src/debug/elf/file.go
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -25,6 +25,7 @@ import (
"internal/saferio"
"internal/zstd"
"io"
"math"
"os"
"strings"
"unsafe"
Expand Down Expand Up @@ -830,17 +831,19 @@ func (f *File) applyRelocationsAMD64(dst []byte, rels []byte) error {

switch t {
case R_X86_64_64:
if rela.Off+8 >= uint64(len(dst)) || rela.Addend < 0 {
s, ok := subslice64(dst, rela.Off, 8)
if !ok || rela.Addend < 0 {
continue
}
val64 := sym.Value + uint64(rela.Addend)
f.ByteOrder.PutUint64(dst[rela.Off:rela.Off+8], val64)
f.ByteOrder.PutUint64(s, val64)
case R_X86_64_32:
if rela.Off+4 >= uint64(len(dst)) || rela.Addend < 0 {
s, ok := subslice64(dst, rela.Off, 4)
if !ok || rela.Addend < 0 {
continue
}
val32 := uint32(sym.Value) + uint32(rela.Addend)
f.ByteOrder.PutUint32(dst[rela.Off:rela.Off+4], val32)
f.ByteOrder.PutUint32(s, val32)
}
}

Expand Down Expand Up @@ -872,12 +875,13 @@ func (f *File) applyRelocations386(dst []byte, rels []byte) error {
sym := &symbols[symNo-1]

if t == R_386_32 {
if rel.Off+4 >= uint32(len(dst)) {
s, ok := subslice32(dst, rel.Off, 4)
if !ok {
continue
}
val := f.ByteOrder.Uint32(dst[rel.Off : rel.Off+4])
val := f.ByteOrder.Uint32(s)
val += uint32(sym.Value)
f.ByteOrder.PutUint32(dst[rel.Off:rel.Off+4], val)
f.ByteOrder.PutUint32(s, val)
}
}

Expand Down Expand Up @@ -910,12 +914,13 @@ func (f *File) applyRelocationsARM(dst []byte, rels []byte) error {

switch t {
case R_ARM_ABS32:
if rel.Off+4 >= uint32(len(dst)) {
s, ok := subslice32(dst, rel.Off, 4)
if !ok {
continue
}
val := f.ByteOrder.Uint32(dst[rel.Off : rel.Off+4])
val := f.ByteOrder.Uint32(s)
val += uint32(sym.Value)
f.ByteOrder.PutUint32(dst[rel.Off:rel.Off+4], val)
f.ByteOrder.PutUint32(s, val)
}
}

Expand Down Expand Up @@ -955,17 +960,19 @@ func (f *File) applyRelocationsARM64(dst []byte, rels []byte) error {

switch t {
case R_AARCH64_ABS64:
if rela.Off+8 >= uint64(len(dst)) || rela.Addend < 0 {
s, ok := subslice64(dst, rela.Off, 8)
if !ok || rela.Addend < 0 {
continue
}
val64 := sym.Value + uint64(rela.Addend)
f.ByteOrder.PutUint64(dst[rela.Off:rela.Off+8], val64)
f.ByteOrder.PutUint64(s, val64)
case R_AARCH64_ABS32:
if rela.Off+4 >= uint64(len(dst)) || rela.Addend < 0 {
s, ok := subslice64(dst, rela.Off, 4)
if !ok || rela.Addend < 0 {
continue
}
val32 := uint32(sym.Value) + uint32(rela.Addend)
f.ByteOrder.PutUint32(dst[rela.Off:rela.Off+4], val32)
f.ByteOrder.PutUint32(s, val32)
}
}

Expand Down Expand Up @@ -1001,11 +1008,12 @@ func (f *File) applyRelocationsPPC(dst []byte, rels []byte) error {

switch t {
case R_PPC_ADDR32:
if rela.Off+4 >= uint32(len(dst)) || rela.Addend < 0 {
s, ok := subslice32(dst, rela.Off, 4)
if !ok || rela.Addend < 0 {
continue
}
val32 := uint32(sym.Value) + uint32(rela.Addend)
f.ByteOrder.PutUint32(dst[rela.Off:rela.Off+4], val32)
f.ByteOrder.PutUint32(s, val32)
}
}

Expand Down Expand Up @@ -1041,17 +1049,19 @@ func (f *File) applyRelocationsPPC64(dst []byte, rels []byte) error {

switch t {
case R_PPC64_ADDR64:
if rela.Off+8 >= uint64(len(dst)) || rela.Addend < 0 {
s, ok := subslice64(dst, rela.Off, 8)
if !ok || rela.Addend < 0 {
continue
}
val64 := sym.Value + uint64(rela.Addend)
f.ByteOrder.PutUint64(dst[rela.Off:rela.Off+8], val64)
f.ByteOrder.PutUint64(s, val64)
case R_PPC64_ADDR32:
if rela.Off+4 >= uint64(len(dst)) || rela.Addend < 0 {
s, ok := subslice64(dst, rela.Off, 4)
if !ok || rela.Addend < 0 {
continue
}
val32 := uint32(sym.Value) + uint32(rela.Addend)
f.ByteOrder.PutUint32(dst[rela.Off:rela.Off+4], val32)
f.ByteOrder.PutUint32(s, val32)
}
}

Expand Down Expand Up @@ -1084,12 +1094,13 @@ func (f *File) applyRelocationsMIPS(dst []byte, rels []byte) error {

switch t {
case R_MIPS_32:
if rel.Off+4 >= uint32(len(dst)) {
s, ok := subslice32(dst, rel.Off, 4)
if !ok {
continue
}
val := f.ByteOrder.Uint32(dst[rel.Off : rel.Off+4])
val := f.ByteOrder.Uint32(s)
val += uint32(sym.Value)
f.ByteOrder.PutUint32(dst[rel.Off:rel.Off+4], val)
f.ByteOrder.PutUint32(s, val)
}
}

Expand Down Expand Up @@ -1132,17 +1143,19 @@ func (f *File) applyRelocationsMIPS64(dst []byte, rels []byte) error {

switch t {
case R_MIPS_64:
if rela.Off+8 >= uint64(len(dst)) || rela.Addend < 0 {
s, ok := subslice64(dst, rela.Off, 8)
if !ok || rela.Addend < 0 {
continue
}
val64 := sym.Value + uint64(rela.Addend)
f.ByteOrder.PutUint64(dst[rela.Off:rela.Off+8], val64)
f.ByteOrder.PutUint64(s, val64)
case R_MIPS_32:
if rela.Off+4 >= uint64(len(dst)) || rela.Addend < 0 {
s, ok := subslice64(dst, rela.Off, 4)
if !ok || rela.Addend < 0 {
continue
}
val32 := uint32(sym.Value) + uint32(rela.Addend)
f.ByteOrder.PutUint32(dst[rela.Off:rela.Off+4], val32)
f.ByteOrder.PutUint32(s, val32)
}
}

Expand Down Expand Up @@ -1180,17 +1193,19 @@ func (f *File) applyRelocationsLOONG64(dst []byte, rels []byte) error {

switch t {
case R_LARCH_64:
if rela.Off+8 >= uint64(len(dst)) || rela.Addend < 0 {
s, ok := subslice64(dst, rela.Off, 8)
if !ok || rela.Addend < 0 {
continue
}
val64 := sym.Value + uint64(rela.Addend)
f.ByteOrder.PutUint64(dst[rela.Off:rela.Off+8], val64)
f.ByteOrder.PutUint64(s, val64)
case R_LARCH_32:
if rela.Off+4 >= uint64(len(dst)) || rela.Addend < 0 {
s, ok := subslice64(dst, rela.Off, 4)
if !ok || rela.Addend < 0 {
continue
}
val32 := uint32(sym.Value) + uint32(rela.Addend)
f.ByteOrder.PutUint32(dst[rela.Off:rela.Off+4], val32)
f.ByteOrder.PutUint32(s, val32)
}
}

Expand Down Expand Up @@ -1226,17 +1241,19 @@ func (f *File) applyRelocationsRISCV64(dst []byte, rels []byte) error {

switch t {
case R_RISCV_64:
if rela.Off+8 >= uint64(len(dst)) || rela.Addend < 0 {
s, ok := subslice64(dst, rela.Off, 8)
if !ok || rela.Addend < 0 {
continue
}
val64 := sym.Value + uint64(rela.Addend)
f.ByteOrder.PutUint64(dst[rela.Off:rela.Off+8], val64)
f.ByteOrder.PutUint64(s, val64)
case R_RISCV_32:
if rela.Off+4 >= uint64(len(dst)) || rela.Addend < 0 {
s, ok := subslice64(dst, rela.Off, 4)
if !ok || rela.Addend < 0 {
continue
}
val32 := uint32(sym.Value) + uint32(rela.Addend)
f.ByteOrder.PutUint32(dst[rela.Off:rela.Off+4], val32)
f.ByteOrder.PutUint32(s, val32)
}
}

Expand Down Expand Up @@ -1272,17 +1289,19 @@ func (f *File) applyRelocationss390x(dst []byte, rels []byte) error {

switch t {
case R_390_64:
if rela.Off+8 >= uint64(len(dst)) || rela.Addend < 0 {
s, ok := subslice64(dst, rela.Off, 8)
if !ok || rela.Addend < 0 {
continue
}
val64 := sym.Value + uint64(rela.Addend)
f.ByteOrder.PutUint64(dst[rela.Off:rela.Off+8], val64)
f.ByteOrder.PutUint64(s, val64)
case R_390_32:
if rela.Off+4 >= uint64(len(dst)) || rela.Addend < 0 {
s, ok := subslice64(dst, rela.Off, 4)
if !ok || rela.Addend < 0 {
continue
}
val32 := uint32(sym.Value) + uint32(rela.Addend)
f.ByteOrder.PutUint32(dst[rela.Off:rela.Off+4], val32)
f.ByteOrder.PutUint32(s, val32)
}
}

Expand Down Expand Up @@ -1318,17 +1337,19 @@ func (f *File) applyRelocationsSPARC64(dst []byte, rels []byte) error {

switch t {
case R_SPARC_64, R_SPARC_UA64:
if rela.Off+8 >= uint64(len(dst)) || rela.Addend < 0 {
s, ok := subslice64(dst, rela.Off, 8)
if !ok || rela.Addend < 0 {
continue
}
val64 := sym.Value + uint64(rela.Addend)
f.ByteOrder.PutUint64(dst[rela.Off:rela.Off+8], val64)
f.ByteOrder.PutUint64(s, val64)
case R_SPARC_32, R_SPARC_UA32:
if rela.Off+4 >= uint64(len(dst)) || rela.Addend < 0 {
s, ok := subslice64(dst, rela.Off, 4)
if !ok || rela.Addend < 0 {
continue
}
val32 := uint32(sym.Value) + uint32(rela.Addend)
f.ByteOrder.PutUint32(dst[rela.Off:rela.Off+4], val32)
f.ByteOrder.PutUint32(s, val32)
}
}

Expand Down Expand Up @@ -1903,3 +1924,21 @@ type nobitsSectionReader struct{}
func (*nobitsSectionReader) ReadAt(p []byte, off int64) (n int, err error) {
return 0, errors.New("unexpected read from SHT_NOBITS section")
}

// subslice32 returns slice[start:start+length] and true, if it's valid.
// subslice32 returns nil and false, if the range is out of bounds or if the addition of
// start and length would overflow.
func subslice32(slice []byte, start, length uint32) ([]byte, bool) {
if uint64(start+length) > uint64(len(slice)) || math.MaxUint32-start < length {
return nil, false
}
return slice[start : start+length], true
}

// subslice64 is like subslice32 but using uint64.
func subslice64(slice []byte, start, length uint64) ([]byte, bool) {
if start+length > uint64(len(slice)) || math.MaxUint64-start < length {
return nil, false
}
return slice[start : start+length], true
}
Loading