diff options
| author | Matthew Dempsky <mdempsky@google.com> | 2017-08-31 11:26:28 -0700 |
|---|---|---|
| committer | Matthew Dempsky <mdempsky@google.com> | 2017-09-09 14:13:33 +0000 |
| commit | 3d7042fba341180e63ea27fdfafbbab2499314aa (patch) | |
| tree | d37d63c05d68ddb554701fcddfd45b2e36addf32 /src/cmd/pack/pack.go | |
| parent | 08347648a6261fddc259fd846cf565a03875416a (diff) | |
| download | go-3d7042fba341180e63ea27fdfafbbab2499314aa.tar.xz | |
cmd/pack: fix export data truncation bug
The binary export data format includes escaping to prevent "\n$$" from
appearing internally, but not "\n!\n". This could result in a false
positive when cmd/pack searched for "\n!\n" as the delimiter between
package definition and linker object.
To address this, this CL changes cmd/pack to also be aware of the
"\n$$" markers, and to ignore "\n!\n" within the export data.
Fixes #21703.
Change-Id: I71ea8ba49dbd066c7afb7717ddc0190e38fe5649
Reviewed-on: https://go-review.googlesource.com/60773
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Diffstat (limited to 'src/cmd/pack/pack.go')
| -rw-r--r-- | src/cmd/pack/pack.go | 12 |
1 files changed, 11 insertions, 1 deletions
diff --git a/src/cmd/pack/pack.go b/src/cmd/pack/pack.go index 1c168f946b..3abc83e090 100644 --- a/src/cmd/pack/pack.go +++ b/src/cmd/pack/pack.go @@ -426,8 +426,15 @@ func readPkgdef(file string) (data []byte, err error) { // Read from file, collecting header for __.PKGDEF. // The header is from the beginning of the file until a line // containing just "!". The first line must begin with "go object ". + // + // Note: It's possible for "\n!\n" to appear within the binary + // package export data format. To avoid truncating the package + // definition prematurely (issue 21703), we keep keep track of + // how many "$$" delimiters we've seen. + rbuf := bufio.NewReader(f) var wbuf bytes.Buffer + markers := 0 for { line, err := rbuf.ReadBytes('\n') if err != nil { @@ -436,9 +443,12 @@ func readPkgdef(file string) (data []byte, err error) { if wbuf.Len() == 0 && !bytes.HasPrefix(line, []byte("go object ")) { return nil, errors.New("not a Go object file") } - if bytes.Equal(line, []byte("!\n")) { + if markers%2 == 0 && bytes.Equal(line, []byte("!\n")) { break } + if bytes.HasPrefix(line, []byte("$$")) { + markers++ + } wbuf.Write(line) } return wbuf.Bytes(), nil |