x/crypto/ssh: cannot close ssh session

[XindaH]

What version of Go are you using (go version)?

$ go version
1.17

Does this issue reproduce with the latest release?

yes

What operating system and processor architecture are you using (go env)?

go env Output

$ go env
GO111MODULE="on"
GOARCH="amd64"
GOHOSTARCH="amd64"
GOHOSTOS="darwin"
GOPRIVATE=""
GOPROXY="https://goproxy.cn,direct"
GOROOT="/usr/local/go"
GOSUMDB="sum.golang.org"
GOTMPDIR=""
GOTOOLDIR="/usr/local/go/pkg/tool/darwin_amd64"
GOVCS=""
GOVERSION="go1.17.6"
GCCGO="gccgo"
AR="ar"
CC="clang"
CXX="clang++"
CGO_ENABLED="1"
CGO_CFLAGS="-g -O2"
CGO_CPPFLAGS=""
CGO_CXXFLAGS="-g -O2"
CGO_FFLAGS="-g -O2"
CGO_LDFLAGS="-g -O2"
PKG_CONFIG="pkg-config"
GOGCCFLAGS="-fPIC -arch x86_64 -m64 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -fdebug-prefix-map=/var/folders/jx/d_08_gm93psc4v9lm3zzjc300000gn/T/go-build1736071007=/tmp/go-build -gno-record-gcc-switches -fno-common"

What did you do?

func test() {
	client, err := ssh.Dial("tcp", "xx.xx.xx.xx:22", &ssh.ClientConfig{
		User:            "root",
		Auth:            []ssh.AuthMethod{ssh.Password("123")},
		HostKeyCallback: ssh.InsecureIgnoreHostKey(),
	})
	if err != nil {
		log.Panic(err)
	}
	session, err := client.NewSession()
	if err != nil {
		log.Panic(err)
	}
	defer session.Close()
	go func() {
		// err := session.Run("while true;do echo test;done")
		err := session.Run("sleep 6000")
		if err != nil {
			log.Println(err)
		}
	}()
	time.Sleep(time.Second * 5)

	err = session.Close()
	if err != nil {
		log.Println(err)
	}
	log.Println("finished")
}

What did you expect to see?

2022/04/12 13:35:17 finished
2022/04/12 13:35:17 Process exited with status 141 from signal PIPE

What did you see instead?

2022/04/12 13:35:17 finished

If I run while true;do echo test;done, the session can be closed gracefully. However sleep 6000 is still running after this process finished.

[ianlancetaylor]

This looks related to #23019.

[XindaH]

This looks related to #23019.

maybe different👀

[dmitshur]

CC @FiloSottile.