From 4d6ca68a85e42c75683bc96aa540207566f54e26 Mon Sep 17 00:00:00 2001 From: "Bryan C. Mills" Date: Wed, 28 Sep 2022 13:29:12 -0400 Subject: os/exec: do not close pipes on a double-Start error This fixes a bug introduced in CL 401834 in which calling Start twice with pipes attached to a command would spuriously close those pipes when returning the error from the second Start call. For #50436. Change-Id: I3563cc99c0a0987752190fef95da3e9927a76fda Reviewed-on: https://go-review.googlesource.com/c/go/+/436095 Reviewed-by: Ian Lance Taylor TryBot-Result: Gopher Robot Run-TryBot: Bryan Mills Auto-Submit: Bryan Mills --- src/os/exec/exec.go | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) (limited to 'src/os/exec/exec.go') diff --git a/src/os/exec/exec.go b/src/os/exec/exec.go index 67dd379b71..0dac34447f 100644 --- a/src/os/exec/exec.go +++ b/src/os/exec/exec.go @@ -490,6 +490,12 @@ func lookExtensions(path, dir string) (string, error) { // After a successful call to Start the Wait method must be called in // order to release associated system resources. func (c *Cmd) Start() error { + // Check for doubled Start calls before we defer failure cleanup. If the prior + // call to Start succeeded, we don't want to spuriously close its pipes. + if c.Process != nil { + return errors.New("exec: already started") + } + started := false defer func() { c.closeDescriptors(c.childIOFiles) @@ -519,9 +525,6 @@ func (c *Cmd) Start() error { } c.Path = lp } - if c.Process != nil { - return errors.New("exec: already started") - } if c.ctx != nil { select { case <-c.ctx.Done(): -- cgit v1.3