From c1a9f01f226133e3b8539ce678871fe1c0a68270 Mon Sep 17 00:00:00 2001
From: Itay Bookstein <ibookstein@gmail.com>
Date: Thu, 27 Mar 2025 09:48:56 +0200
Subject: [PATCH] linux: allow nul bytes in abstract socket address (#4737)

Documentation on Linux explains that nul bytes have no
special significance in abstract namespace socket names.
Avoid precluding such addresses.

Signed-off-by: Itay Bookstein <ibookstein@gmail.com>
---
 src/unix/pipe.c              | 14 ++++++++------
 test/test-pipe-getsockname.c |  4 ++--
 2 files changed, 10 insertions(+), 8 deletions(-)

diff --git a/src/unix/pipe.c b/src/unix/pipe.c
index bd57b17f..6bfe6cf2 100644
--- a/src/unix/pipe.c
+++ b/src/unix/pipe.c
@@ -31,13 +31,15 @@
 
 
 /* Does the file path contain embedded nul bytes? */
-static int includes_nul(const char *s, size_t n) {
+static int includes_invalid_nul(const char *s, size_t n) {
   if (n == 0)
     return 0;
 #ifdef __linux__
-  /* Accept abstract socket namespace path ("\0/virtual/path"). */
-  s++;
-  n--;
+  /* Accept abstract socket namespace paths, throughout which nul bytes have
+   * no special significance ("\0foo\0bar").
+   */
+  if (s[0] == '\0')
+    return 0;
 #endif
   return NULL != memchr(s, '\0', n);
 }
@@ -84,7 +86,7 @@ int uv_pipe_bind2(uv_pipe_t* handle,
     return UV_EINVAL;
 #endif
 
-  if (includes_nul(name, namelen))
+  if (includes_invalid_nul(name, namelen))
     return UV_EINVAL;
 
   if (flags & UV_PIPE_NO_TRUNCATE)
@@ -271,7 +273,7 @@ int uv_pipe_connect2(uv_connect_t* req,
   if (namelen == 0)
     return UV_EINVAL;
 
-  if (includes_nul(name, namelen))
+  if (includes_invalid_nul(name, namelen))
     return UV_EINVAL;
 
   if (flags & UV_PIPE_NO_TRUNCATE)
diff --git a/test/test-pipe-getsockname.c b/test/test-pipe-getsockname.c
index cc345ccd..3be30e67 100644
--- a/test/test-pipe-getsockname.c
+++ b/test/test-pipe-getsockname.c
@@ -59,7 +59,7 @@ static void pipe_client_connect_cb(uv_connect_t* req, int status) {
   ASSERT_OK(r);
 
   if (*buf == '\0') {  /* Linux abstract socket. */
-    const char expected[] = "\0" TEST_PIPENAME;
+    const char expected[] = "\0" TEST_PIPENAME "\0";
     ASSERT_EQ(len, sizeof(expected) - 1);
     ASSERT_MEM_EQ(buf, expected, len);
   } else {
@@ -223,7 +223,7 @@ TEST_IMPL(pipe_getsockname) {
 
 TEST_IMPL(pipe_getsockname_abstract) {
   /* TODO(bnoordhuis) Use unique name, susceptible to concurrent test runs. */
-  static const char name[] = "\0" TEST_PIPENAME;
+  static const char name[] = "\0" TEST_PIPENAME "\0";
 #if defined(__linux__)
   char buf[256];
   size_t buflen;