From 50054f565972e51ecd4ec72f9a24fc80175317d8 Mon Sep 17 00:00:00 2001
From: Simone Basso <bassosimone@gmail.com>
Date: Thu, 16 Mar 2023 17:24:08 +0100
Subject: [PATCH] [backport] fix(webconnectivitylte): avoid data race

This diff backports 297360dfa007583c3fcd75bc83e516b82d93f8be.

Closes https://github.com/ooni/probe/issues/2434
---
 internal/experiment/webconnectivitylte/iox.go      | 4 +++-
 internal/experiment/webconnectivitylte/measurer.go | 2 +-
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/internal/experiment/webconnectivitylte/iox.go b/internal/experiment/webconnectivitylte/iox.go
index 5063e0db73..4ae851c4a2 100644
--- a/internal/experiment/webconnectivitylte/iox.go
+++ b/internal/experiment/webconnectivitylte/iox.go
@@ -33,8 +33,10 @@ func StreamAllContext(ctx context.Context, reader io.Reader) ([]byte, error) {
 	defer cancel()
 
 	go func() {
-		buffer := make([]byte, 1<<13)
 		for {
+			// Implementation note: the buffer MUST be created at each
+			// loop, otherwise we're data-racing with the reader.
+			buffer := make([]byte, 1<<13)
 			count, err := reader.Read(buffer)
 			if count > 0 {
 				data := buffer[:count]
diff --git a/internal/experiment/webconnectivitylte/measurer.go b/internal/experiment/webconnectivitylte/measurer.go
index 9926150c18..2eeef646d0 100644
--- a/internal/experiment/webconnectivitylte/measurer.go
+++ b/internal/experiment/webconnectivitylte/measurer.go
@@ -37,7 +37,7 @@ func (m *Measurer) ExperimentName() string {
 
 // ExperimentVersion implements model.ExperimentMeasurer.
 func (m *Measurer) ExperimentVersion() string {
-	return "0.5.22"
+	return "0.5.23"
 }
 
 // Run implements model.ExperimentMeasurer.