net/http/fcgi: fix race in child.serve connection read
Guards the connection read with a mutex, because typeStdin
asynchronously and concurrently writes to the underlying conn.
Fixes #41167
Change-Id: Ia2610f4fde0bd4b108c54164095ea293980b0301
Reviewed-on: https://go-review.googlesource.com/c/go/+/252417
Run-TryBot: Emmanuel Odeke <emm.odeke@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
diff --git a/src/net/http/fcgi/child.go b/src/net/http/fcgi/child.go
index 30a6b2c..0e91042 100644
--- a/src/net/http/fcgi/child.go
+++ b/src/net/http/fcgi/child.go
@@ -155,9 +155,12 @@
defer c.cleanUp()
var rec record
for {
+ c.conn.mutex.Lock()
if err := rec.read(c.conn.rwc); err != nil {
+ c.conn.mutex.Unlock()
return
}
+ c.conn.mutex.Unlock()
if err := c.handleRecord(&rec); err != nil {
return
}
