libpod: fix race when closing STDIN

There is a race where `conn.Close()` was called before `conn.CloseWrite()`.
In this case `CloseWrite` will fail and an useless error is printed. To
fix this we move the the `CloseWrite()` call to the same goroutine to
remove the race. This ensures that `CloseWrite()` is called before
`Close()` and never afterwards.
Also fixed podman-remote run where the STDIN was never was closed.
This is causing flakes in CI testing.

[NO TESTS NEEDED]

Fixes #11856

Signed-off-by: Paul Holzinger <pholzing@redhat.com>

<MH: Fixed cherry-pick conflicts>

Signed-off-by: Matthew Heon <matthew.heon@pm.me>

1 files changed, 4 insertions, 3 deletions

diff --git a/libpod/oci_conmon_exec_linux.go b/libpod/oci_conmon_exec_linux.go
index 5a7677b04..553c91833 100644
--- a/libpod/oci_conmon_exec_linux.go
+++ b/libpod/oci_conmon_exec_linux.go
@@ -609,9 +609,6 @@ func attachExecHTTP(c *Container, sessionID string, r *http.Request, w http.Resp
 			_, err := utils.CopyDetachable(conn, httpBuf, detachKeys)
 			logrus.Debugf("STDIN copy completed")
 			stdinChan <- err
-			if connErr := conn.CloseWrite(); connErr != nil {
-				logrus.Errorf("Unable to close conn: %v", connErr)
-			}
 		}()
 	}
 
@@ -654,6 +651,10 @@ func attachExecHTTP(c *Container, sessionID string, r *http.Request, w http.Resp
 			if err != nil {
 				return err
 			}
+			// copy stdin is done, close it
+			if connErr := conn.CloseWrite(); connErr != nil {
+				logrus.Errorf("Unable to close conn: %v", connErr)
+			}
 		case <-cancel:
 			return nil
 		}