containerd CRI stream server: Host memory exhaustion through terminal resize goroutine leak

@@ -33,6 +33,7 @@ limitations under the License.
 package remotecommand
 
 import (
+	gocontext "context"
 	"encoding/json"
 	"errors"
 	"fmt"
@@ -132,7 +133,7 @@ func createStreams(req *http.Request, w http.ResponseWriter, opts *Options, supp
 
 	if ctx.resizeStream != nil {
 		ctx.resizeChan = make(chan remotecommand.TerminalSize)
-		go handleResizeEvents(ctx.resizeStream, ctx.resizeChan)
+		go handleResizeEvents(req.Context(), ctx.resizeStream, ctx.resizeChan)
 	}
 
 	return ctx, true
@@ -425,7 +426,7 @@ WaitForStreams:
 // supportsTerminalResizing returns false because v1ProtocolHandler doesn't support it.
 func (*v1ProtocolHandler) supportsTerminalResizing() bool { return false }
 
-func handleResizeEvents(stream io.Reader, channel chan<- remotecommand.TerminalSize) {
+func handleResizeEvents(ctx gocontext.Context, stream io.Reader, channel chan<- remotecommand.TerminalSize) {
 	defer runtime.HandleCrash()
 	defer close(channel)
 
@@ -435,7 +436,15 @@ func handleResizeEvents(stream io.Reader, channel chan<- remotecommand.TerminalS
 		if err := decoder.Decode(&size); err != nil {
 			break
 		}
-		channel <- size
+
+		select {
+		case channel <- size:
+		case <-ctx.Done():
+			// To avoid leaking this routine, exit if the http request finishes. This path
+			// would generally be hit if starting the process fails and nothing is started to
+			// ingest these resize events.
+			return
+		}
 	}
 }
 

@@ -0,0 +1,19 @@
+# commit to be tagged for new release
+commit = "HEAD"
+
+project_name = "containerd"
+github_repo = "containerd/containerd"
+match_deps = "^github.com/(containerd/[a-zA-Z0-9-]+)$"
+
+# previous release
+previous = "v1.6.11"
+
+pre_release = false
+
+preface = """\
+The twelfth patch release for containerd 1.6 contains a fix for CVE-2022-23471.
+
+### Notable Updates
+* **Fix goroutine leak during Exec in CRI plugin** ([GHSA-2qjp-425j-52j9](https://github.com/containerd/containerd/security/advisories/GHSA-2qjp-425j-52j9))
+
+See the changelog for complete list of changes"""

@@ -23,7 +23,7 @@ var (
 	Package = "github.com/containerd/containerd"
 
 	// Version holds the complete version number. Filled in at linking time.
-	Version = "1.6.11+unknown"
+	Version = "1.6.12+unknown"
 
 	// Revision is filled with the VCS (e.g. git) revision being used to build
 	// the program at linking time.

@@ -33,6 +33,7 @@ limitations under the License.
 package remotecommand
 
 import (
+	gocontext "context"
 	"encoding/json"
 	"errors"
 	"fmt"
@@ -132,7 +133,7 @@ func createStreams(req *http.Request, w http.ResponseWriter, opts *Options, supp
 
 	if ctx.resizeStream != nil {
 		ctx.resizeChan = make(chan remotecommand.TerminalSize)
-		go handleResizeEvents(ctx.resizeStream, ctx.resizeChan)
+		go handleResizeEvents(req.Context(), ctx.resizeStream, ctx.resizeChan)
 	}
 
 	return ctx, true
@@ -425,7 +426,7 @@ WaitForStreams:
 // supportsTerminalResizing returns false because v1ProtocolHandler doesn't support it.
 func (*v1ProtocolHandler) supportsTerminalResizing() bool { return false }
 
-func handleResizeEvents(stream io.Reader, channel chan<- remotecommand.TerminalSize) {
+func handleResizeEvents(ctx gocontext.Context, stream io.Reader, channel chan<- remotecommand.TerminalSize) {
 	defer runtime.HandleCrash()
 	defer close(channel)
 
@@ -435,7 +436,15 @@ func handleResizeEvents(stream io.Reader, channel chan<- remotecommand.TerminalS
 		if err := decoder.Decode(&size); err != nil {
 			break
 		}
-		channel <- size
+
+		select {
+		case channel <- size:
+		case <-ctx.Done():
+			// To avoid leaking this routine, exit if the http request finishes. This path
+			// would generally be hit if starting the process fails and nothing is started to
+			// ingest these resize events.
+			return
+		}
 	}
 }