From d33aead28bcec32a2a450f884907a6d971631829 Mon Sep 17 00:00:00 2001
From: Ben Noordhuis <info@bnoordhuis.nl>
Date: Fri, 21 May 2021 11:23:36 +0200
Subject: [PATCH] deps: uv: cherry-pick 99c29c9c2c9b

Original commit message:

    idna: fix OOB read in punycode decoder

    Reported by Eric Sesterhenn in collaboration with
    Cure53 and ExpressVPN.

    Deleted unintroduced test files.

    Reported-By: Eric Sesterhenn <eric.sesterhenn@x41-dsec.de>
    PR-URL: https://github.com/libuv/libuv-private/pull/1
    Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
    Reviewed-By: Richard Lau <rlau@redhat.com>

CVE-ID: CVE-2021-22918
Refs: https://hackerone.com/reports/1209681
PR-URL: https://github.com/nodejs-private/node-private/pull/267
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Richard Lau <rlau@redhat.com>
Reviewed-By: Michael Dawson <midawson@redhat.com>
Reviewed-By: Beth Griggs <bgriggs@redhat.com>
---
 deps/uv/src/idna.c | 49 ++++++++++++++++++++++++++++++++++------------
 1 file changed, 36 insertions(+), 13 deletions(-)

diff --git a/deps/uv/src/idna.c b/deps/uv/src/idna.c
index 13ffac6..b44cb16 100644
--- a/deps/uv/src/idna.c
+++ b/deps/uv/src/idna.c
@@ -19,6 +19,7 @@
 
 #include "uv.h"
 #include "idna.h"
+#include <assert.h>
 #include <string.h>
 
 static unsigned uv__utf8_decode1_slow(const char** p,
@@ -32,7 +33,7 @@ static unsigned uv__utf8_decode1_slow(const char** p,
   if (a > 0xF7)
     return -1;
 
-  switch (*p - pe) {
+  switch (pe - *p) {
   default:
     if (a > 0xEF) {
       min = 0x10000;
@@ -62,6 +63,8 @@ static unsigned uv__utf8_decode1_slow(const char** p,
       a = 0;
       break;
     }
+    /* Fall through. */
+  case 0:
     return -1;  /* Invalid continuation byte. */
   }
 
@@ -88,6 +91,8 @@ static unsigned uv__utf8_decode1_slow(const char** p,
 unsigned uv__utf8_decode1(const char** p, const char* pe) {
   unsigned a;
 
+  assert(*p < pe);
+
   a = (unsigned char) *(*p)++;
 
   if (a < 128)
@@ -96,9 +101,6 @@ unsigned uv__utf8_decode1(const char** p, const char* pe) {
   return uv__utf8_decode1_slow(p, pe, a);
 }
 
-#define foreach_codepoint(c, p, pe) \
-  for (; (void) (*p <= pe && (c = uv__utf8_decode1(p, pe))), *p <= pe;)
-
 static int uv__idna_toascii_label(const char* s, const char* se,
                                   char** d, char* de) {
   static const char alphabet[] = "abcdefghijklmnopqrstuvwxyz0123456789";
@@ -121,15 +123,22 @@ static int uv__idna_toascii_label(const char* s, const char* se,
   ss = s;
   todo = 0;
 
-  foreach_codepoint(c, &s, se) {
+  /* Note: after this loop we've visited all UTF-8 characters and know
+   * they're legal so we no longer need to check for decode errors.
+   */
+  while (s < se) {
+    c = uv__utf8_decode1(&s, se);
+
+    if (c == -1u)
+      return UV_EINVAL;
+
     if (c < 128)
       h++;
-    else if (c == (unsigned) -1)
-      return UV_EINVAL;
     else
       todo++;
   }
 
+  /* Only write "xn--" when there are non-ASCII characters. */
   if (todo > 0) {
     if (*d < de) *(*d)++ = 'x';
     if (*d < de) *(*d)++ = 'n';
@@ -137,9 +146,13 @@ static int uv__idna_toascii_label(const char* s, const char* se,
     if (*d < de) *(*d)++ = '-';
   }
 
+  /* Write ASCII characters. */
   x = 0;
   s = ss;
-  foreach_codepoint(c, &s, se) {
+  while (s < se) {
+    c = uv__utf8_decode1(&s, se);
+    assert(c != -1u);
+
     if (c > 127)
       continue;
 
@@ -166,10 +179,15 @@ static int uv__idna_toascii_label(const char* s, const char* se,
   while (todo > 0) {
     m = -1;
     s = ss;
-    foreach_codepoint(c, &s, se)
+
+    while (s < se) {
+      c = uv__utf8_decode1(&s, se);
+      assert(c != -1u);
+
       if (c >= n)
         if (c < m)
           m = c;
+    }
 
     x = m - n;
     y = h + 1;
@@ -181,7 +199,10 @@ static int uv__idna_toascii_label(const char* s, const char* se,
     n = m;
 
     s = ss;
-    foreach_codepoint(c, &s, se) {
+    while (s < se) {
+      c = uv__utf8_decode1(&s, se);
+      assert(c != -1u);
+
       if (c < n)
         if (++delta == 0)
           return UV_E2BIG;  /* Overflow. */
@@ -245,8 +266,6 @@ static int uv__idna_toascii_label(const char* s, const char* se,
   return 0;
 }
 
-#undef foreach_codepoint
-
 long uv__idna_toascii(const char* s, const char* se, char* d, char* de) {
   const char* si;
   const char* st;
@@ -256,10 +275,14 @@ long uv__idna_toascii(const char* s, const char* se, char* d, char* de) {
 
   ds = d;
 
-  for (si = s; si < se; /* empty */) {
+  si = s;
+  while (si < se) {
     st = si;
     c = uv__utf8_decode1(&si, se);
 
+    if (c == -1u)
+      return UV_EINVAL;
+
     if (c != '.')
       if (c != 0x3002)  /* 。 */
         if (c != 0xFF0E)  /* ． */
-- 
2.27.0