From 5a52fcc5466a7da26994ac168d56ee5e9cd21ae9 Mon Sep 17 00:00:00 2001
From: Bhasker Hariharan <bhaskerh@google.com>
Date: Wed, 9 Feb 2022 22:58:41 -0800
Subject: [PATCH] Fix buffer aliasing issue when Merging views.

PiperOrigin-RevId: 427662565
---
 pkg/buffer/view.go | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/pkg/buffer/view.go b/pkg/buffer/view.go
index 53167c28a..13839e255 100644
--- a/pkg/buffer/view.go
+++ b/pkg/buffer/view.go
@@ -385,6 +385,10 @@ func (v *View) Clone() View {
 		size: v.size,
 	}
 	for buf := v.data.Front(); buf != nil; buf = buf.Next() {
+		// Copy the buffer structs itself as they are stateful and
+		// should not be shared between Views.
+		//
+		// TODO(gvisor.dev/issue/7158): revisit need for View.pool.
 		newBuf := other.pool.getNoInit()
 		*newBuf = *buf
 		other.data.PushBack(newBuf)
@@ -428,7 +432,13 @@ func (v *View) Merge(other *View) {
 	// Copy over all buffers.
 	for buf := other.data.Front(); buf != nil; buf = other.data.Front() {
 		other.data.Remove(buf)
-		v.data.PushBack(buf)
+		// Copy the buffer structs itself as they are stateful and
+		// should not be shared between Views.
+		//
+		// TODO(gvisor.dev/issue/7158): revisit need for View.pool.
+		newBuf := v.pool.getNoInit()
+		*newBuf = *buf
+		v.data.PushBack(newBuf)
 	}
 
 	// Adjust sizes.