From: Ian Lance Taylor <iant@golang.org>
Date: Thu, 23 Jun 2022 23:36:08 +0000 (-0700)
Subject: internal/xcoff: use saferio to read string table
X-Git-Tag: go1.20rc1~1606
X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=0d8efa6e842169e61cbe343441092b6f7c9b886c;p=gostls13.git

internal/xcoff: use saferio to read string table

No test case because the problem can only happen for invalid data.
Let the fuzzer find cases like this.

For #47653
Fixes #52526

Change-Id: Id90a5e391a4f684f45f8d7e32608eb03b8081076
Reviewed-on: https://go-review.googlesource.com/c/go/+/413875
Reviewed-by: Ian Lance Taylor <iant@google.com>
Run-TryBot: Ian Lance Taylor <iant@google.com>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Tobias Klauser <tobias.klauser@gmail.com>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Auto-Submit: Ian Lance Taylor <iant@google.com>
---

diff --git a/src/internal/xcoff/file.go b/src/internal/xcoff/file.go
index 553103bdff..1c5a266caf 100644
--- a/src/internal/xcoff/file.go
+++ b/src/internal/xcoff/file.go
@@ -9,6 +9,7 @@ import (
 	"debug/dwarf"
 	"encoding/binary"
 	"fmt"
+	"internal/saferio"
 	"io"
 	"os"
 	"strings"
@@ -213,13 +214,11 @@ func NewFile(r io.ReaderAt) (*File, error) {
 		return nil, err
 	}
 	if l > 4 {
-		if _, err := sr.Seek(int64(offset), io.SeekStart); err != nil {
-			return nil, err
-		}
-		f.StringTable = make([]byte, l)
-		if _, err := io.ReadFull(sr, f.StringTable); err != nil {
+		st, err := saferio.ReadDataAt(sr, uint64(l), int64(offset))
+		if err != nil {
 			return nil, err
 		}
+		f.StringTable = st
 	}
 
 	// Read section headers