golang/0053-net-http-httputil-close-incoming-ReverseProxy-reques.patch

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2.0 KiB
Diff

From b7a85e0003cedb1b48a1fd3ae5b746ec6330102e Mon Sep 17 00:00:00 2001
From: Damien Neil <dneil@google.com>
Date: Wed, 7 Jul 2021 16:34:34 -0700
Subject: [PATCH] net/http/httputil: close incoming ReverseProxy request body
Reading from an incoming request body after the request handler aborts
with a panic can cause a panic, becuse http.Server does not (contrary
to its documentation) close the request body in this case.
Always close the incoming request body in ReverseProxy.ServeHTTP to
ensure that any in-flight outgoing requests using the body do not
read from it.
Updates #46866
Fixes CVE-2021-36221
Change-Id: I310df269200ad8732c5d9f1a2b00de68725831df
Reviewed-on: https://go-review.googlesource.com/c/go/+/333191
Trust: Damien Neil <dneil@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Filippo Valsorda <filippo@golang.org>
---
src/net/http/httputil/reverseproxy.go | 9 +++++
src/net/http/httputil/reverseproxy_test.go | 39 ++++++++++++++++++++++
2 files changed, 48 insertions(+)
diff --git a/src/net/http/httputil/reverseproxy.go b/src/net/http/httputil/reverseproxy.go
index 5d39955d62..8b63368386 100644
--- a/src/net/http/httputil/reverseproxy.go
+++ b/src/net/http/httputil/reverseproxy.go
@@ -235,6 +235,15 @@ func (p *ReverseProxy) ServeHTTP(rw http.ResponseWriter, req *http.Request) {
if req.ContentLength == 0 {
outreq.Body = nil // Issue 16036: nil Body for http.Transport retries
}
+ if outreq.Body != nil {
+ // Reading from the request body after returning from a handler is not
+ // allowed, and the RoundTrip goroutine that reads the Body can outlive
+ // this handler. This can lead to a crash if the handler panics (see
+ // Issue 46866). Although calling Close doesn't guarantee there isn't
+ // any Read in flight after the handle returns, in practice it's safe to
+ // read after closing it.
+ defer outreq.Body.Close()
+ }
if outreq.Header == nil {
outreq.Header = make(http.Header) // Issue 33142: historical behavior was to always allocate
}
--
2.27.0