From d83d0abfbf6f914303c1b33d954aa115accbd999 Mon Sep 17 00:00:00 2001 From: Matthew Heon Date: Tue, 14 May 2019 14:54:21 -0400 Subject: Ensure that start() in StartAndAttach() is locked StartAndAttach() runs start() in a goroutine, which can allow it to fire after the caller returns - and thus, after the defer to unlock the container lock has fired. The start() call _must_ occur while the container is locked, or else state inconsistencies may occur. Fixes #3114 Signed-off-by: Matthew Heon --- libpod/container_api.go | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) (limited to 'libpod/container_api.go') diff --git a/libpod/container_api.go b/libpod/container_api.go index 5bb610aab..06a31da11 100644 --- a/libpod/container_api.go +++ b/libpod/container_api.go @@ -7,6 +7,7 @@ import ( "io/ioutil" "os" "strconv" + "sync" "time" "github.com/containers/libpod/libpod/driver" @@ -119,13 +120,20 @@ func (c *Container) StartAndAttach(ctx context.Context, streams *AttachStreams, attachChan := make(chan error) + // We need to ensure that we don't return until start() fired in attach. + // Use a WaitGroup to sync this. + wg := new(sync.WaitGroup) + wg.Add(1) + // Attach to the container before starting it go func() { - if err := c.attach(streams, keys, resize, true); err != nil { + if err := c.attach(streams, keys, resize, true, wg); err != nil { attachChan <- err } close(attachChan) }() + + wg.Wait() c.newContainerEvent(events.Attach) return attachChan, nil } @@ -398,7 +406,7 @@ func (c *Container) Attach(streams *AttachStreams, keys string, resize <-chan re return errors.Wrapf(ErrCtrStateInvalid, "can only attach to created or running containers") } defer c.newContainerEvent(events.Attach) - return c.attach(streams, keys, resize, false) + return c.attach(streams, keys, resize, false, nil) } // Mount mounts a container's filesystem on the host -- cgit v1.2.3-54-g00ecf