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internal/app/sppulse: correctly handle small cookie

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The trailing zero bytes need to be sliced off, so send cookie size alongside buffer content.

Signed-off-by: Ophestra <cat@gensokyo.uk>
This commit is contained in:
Ophestra
2025-10-17 08:03:03 +09:00
parent 792013cefb
commit 82299d34c6
3 changed files with 282 additions and 29 deletions
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38
internal/app/sppulse.go
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@@ -24,6 +24,8 @@ func init() { gob.Register(new(spPulseOp)) }
type spPulseOp struct {
// PulseAudio cookie data, populated during toSystem if a cookie is present.
Cookie *[pulseCookieSizeMax]byte
// PulseAudio cookie size, populated during toSystem if a cookie is present.
CookieSize int
}
func (s *spPulseOp) toSystem(state *outcomeStateSys) error {
@@ -60,7 +62,7 @@ func (s *spPulseOp) toSystem(state *outcomeStateSys) error {
return err
} else if a != nil {
s.Cookie = new([pulseCookieSizeMax]byte)
if err = loadFile(state.msg, state.k, "PulseAudio cookie", a.String(), s.Cookie[:]); err != nil {
if s.CookieSize, err = loadFile(state.msg, state.k, "PulseAudio cookie", a.String(), s.Cookie[:]); err != nil {
return err
}
} else {
@@ -80,8 +82,12 @@ func (s *spPulseOp) toContainer(state *outcomeStateParams) error {
if s.Cookie != nil {
innerDst := hst.AbsPrivateTmp.Append("/pulse-cookie")
if s.CookieSize < 0 || s.CookieSize > pulseCookieSizeMax {
return newWithMessage("unexpected PulseAudio cookie size")
}
state.env["PULSE_COOKIE"] = innerDst.String()
state.params.Place(innerDst, s.Cookie[:])
state.params.Place(innerDst, s.Cookie[:s.CookieSize])
}
return nil
@@ -161,44 +167,44 @@ func discoverPulseCookie(k syscallDispatcher) (*check.Absolute, error) {
func loadFile(
msg message.Msg, k syscallDispatcher,
description, pathname string, buf []byte,
) error {
) (int, error) {
n := len(buf)
if n == 0 {
return errors.New("invalid buffer")
return -1, errors.New("invalid buffer")
}
msg.Verbosef("loading up to %d bytes from %q", n, pathname)
if fi, err := k.stat(pathname); err != nil {
return &hst.AppError{Step: "access " + description, Err: err}
return -1, &hst.AppError{Step: "access " + description, Err: err}
} else {
if fi.IsDir() {
return &hst.AppError{Step: "read " + description,
return -1, &hst.AppError{Step: "read " + description,
Err: &os.PathError{Op: "stat", Path: pathname, Err: syscall.EISDIR}}
}
if s := fi.Size(); s > int64(n) {
return newWithMessageError(
description+" at "+strconv.Quote(pathname)+" exceeds maximum expected size",
return -1, newWithMessageError(
description+" at "+strconv.Quote(pathname)+" exceeds expected size",
&os.PathError{Op: "stat", Path: pathname, Err: syscall.ENOMEM},
)
} else if s < int64(n) {
msg.Verbosef("%s at %q is %d bytes longer than expected", description, pathname, int64(n)-s)
msg.Verbosef("%s at %q is %d bytes shorter than expected", description, pathname, int64(n)-s)
} else {
msg.Verbosef("loading %d bytes from %q", n, pathname)
}
}
if f, err := k.open(pathname); err != nil {
return &hst.AppError{Step: "open " + description, Err: err}
return -1, &hst.AppError{Step: "open " + description, Err: err}
} else {
if n, err = f.Read(buf); err != nil {
if !errors.Is(err, io.EOF) {
_ = f.Close()
return &hst.AppError{Step: "read " + description, Err: err}
return n, &hst.AppError{Step: "read " + description, Err: err}
}
msg.Verbosef("copied %d bytes from %q", n, pathname)
} // nil error indicates a partial read, which is handled after stat
}
if err = f.Close(); err != nil {
return &hst.AppError{Step: "close " + description, Err: err}
return n, &hst.AppError{Step: "close " + description, Err: err}
}
return nil
return n, nil
}
}