all: update vendored golang.org/x/net

Pull in HTTP/2 security fix:

	1e63c2f08a http2: limit canonical header cache by bytes, not entries

Fixes #56350

Change-Id: Ib14024ed894ba266f05d4a6e8c454234a45677d2
Reviewed-on: https://go-review.googlesource.com/c/go/+/455717
Run-TryBot: Damien Neil <dneil@google.com>
Reviewed-by: Jenny Rakoczy <jenny@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>

1 files changed, 11 insertions, 7 deletions

diff --git a/src/net/http/h2_bundle.go b/src/net/http/h2_bundle.go
index e36b31dfc3..1e0b83d493 100644
--- a/src/net/http/h2_bundle.go
+++ b/src/net/http/h2_bundle.go
@@ -4327,6 +4327,7 @@ type http2serverConn struct {
 	maxFrameSize                int32
 	peerMaxHeaderListSize       uint32            // zero means unknown (default)
 	canonHeader                 map[string]string // http2-lower-case -> Go-Canonical-Case
+	canonHeaderKeysSize         int               // canonHeader keys size in bytes
 	writingFrame                bool              // started writing a frame (on serve goroutine or separate)
 	writingFrameAsync           bool              // started a frame on its own goroutine but haven't heard back on wroteFrameCh
 	needsFrameFlush             bool              // last frame write wasn't a flush
@@ -4508,6 +4509,13 @@ func (sc *http2serverConn) condlogf(err error, format string, args ...interface{
 	}
 }
 
+// maxCachedCanonicalHeadersKeysSize is an arbitrarily-chosen limit on the size
+// of the entries in the canonHeader cache.
+// This should be larger than the size of unique, uncommon header keys likely to
+// be sent by the peer, while not so high as to permit unreasonable memory usage
+// if the peer sends an unbounded number of unique header keys.
+const http2maxCachedCanonicalHeadersKeysSize = 2048
+
 func (sc *http2serverConn) canonicalHeader(v string) string {
 	sc.serveG.check()
 	http2buildCommonHeaderMapsOnce()
@@ -4523,14 +4531,10 @@ func (sc *http2serverConn) canonicalHeader(v string) string {
 		sc.canonHeader = make(map[string]string)
 	}
 	cv = CanonicalHeaderKey(v)
-	// maxCachedCanonicalHeaders is an arbitrarily-chosen limit on the number of
-	// entries in the canonHeader cache. This should be larger than the number
-	// of unique, uncommon header keys likely to be sent by the peer, while not
-	// so high as to permit unreasonable memory usage if the peer sends an unbounded
-	// number of unique header keys.
-	const maxCachedCanonicalHeaders = 32
-	if len(sc.canonHeader) < maxCachedCanonicalHeaders {
+	size := 100 + len(v)*2 // 100 bytes of map overhead + key + value
+	if sc.canonHeaderKeysSize+size <= http2maxCachedCanonicalHeadersKeysSize {
 		sc.canonHeader[v] = cv
+		sc.canonHeaderKeysSize += size
 	}
 	return cv
 }