code review 6514043: os/exec: don't crash when out of fds

os/exec: don't crash when out of fds

Command.Start could crash before if no fds were available
because a nil *os.File of /dev/null was added to the cleanup
list, which crashed before returning the proper error.

[bradfitz, 2012-09-14 19:03:01]

Hello golang-dev@googlegroups.com,

I'd like you to review this change to
https://go.googlecode.com/hg/

[iant2, 2012-09-14 19:38:55]

LGTM

On Fri, Sep 14, 2012 at 12:03 PM,  <bradfitz@golang.org> wrote:
> Reviewers: golang-dev_googlegroups.com,
>
> Message:
> Hello golang-dev@googlegroups.com,
>
> I'd like you to review this change to
> https://go.googlecode.com/hg/
>
>
> Description:
> os/exec: don't crash when out of fds
>
> Command.Start could crash before if no fds were available
> because a nil *os.File of /dev/null was added to the cleanup
> list, which crashed before returning the proper error.
>
> Please review this at http://codereview.appspot.com/6514043/
>
> Affected files:
>   M src/pkg/os/exec/exec.go
>
>
> Index: src/pkg/os/exec/exec.go
> ===================================================================
> --- a/src/pkg/os/exec/exec.go
> +++ b/src/pkg/os/exec/exec.go
> @@ -143,6 +143,9 @@
>  func (c *Cmd) stdin() (f *os.File, err error) {
>         if c.Stdin == nil {
>                 f, err = os.Open(os.DevNull)
> +               if err != nil {
> +                       return
> +               }
>                 c.closeAfterStart = append(c.closeAfterStart, f)
>                 return
>         }
> @@ -182,6 +185,9 @@
>  func (c *Cmd) writerDescriptor(w io.Writer) (f *os.File, err error) {
>         if w == nil {
>                 f, err = os.OpenFile(os.DevNull, os.O_WRONLY, 0)
> +               if err != nil {
> +                       return
> +               }
>                 c.closeAfterStart = append(c.closeAfterStart, f)
>                 return
>         }
>
>

[bradfitz, 2012-09-14 20:40:42]

*** Submitted as http://code.google.com/p/go/source/detail?r=00e1feaa9218 ***

os/exec: don't crash when out of fds

Command.Start could crash before if no fds were available
because a nil *os.File of /dev/null was added to the cleanup
list, which crashed before returning the proper error.

R=golang-dev, iant
CC=golang-dev
http://codereview.appspot.com/6514043