From: Takashi Yano <takashi.yano@nifty.ne.jp>
Date: Tue, 18 Jan 2022 13:17:37 +0000 (+0900)
Subject: Cygwin: fhandler_base: Fix double free caused when open() fails.
X-Git-Tag: cygwin-3.4.0~719
X-Git-Url: https://sourceware.org/git/?a=commitdiff_plain;h=ff539cc0f9ba4e52682a2647e4347ead4f2f8787;p=newlib-cygwin.git

Cygwin: fhandler_base: Fix double free caused when open() fails.

- When open fails, archetype stored in archetypes[] is not cleared.
  This causes double free when next open fail. This patch fixes the
  issue.

Addresses:
  https://cygwin.com/pipermail/cygwin/2022-January/250518.html
---

diff --git a/winsup/cygwin/fhandler.cc b/winsup/cygwin/fhandler.cc
index fc7c0422e..7d427135e 100644
--- a/winsup/cygwin/fhandler.cc
+++ b/winsup/cygwin/fhandler.cc
@@ -440,8 +440,8 @@ fhandler_base::open_with_arch (int flags, mode_t mode)
   if (!(res = (archetype && archetype->io_handle)
 	|| open (flags, mode & 07777)))
     {
-      if (archetype)
-	delete archetype;
+      if (archetype && archetype->usecount == 0)
+	cygheap->fdtab.delete_archetype (archetype);
     }
   else if (archetype)
     {
diff --git a/winsup/cygwin/release/3.3.4 b/winsup/cygwin/release/3.3.4
index e09ffefdf..3fa9b9e9c 100644
--- a/winsup/cygwin/release/3.3.4
+++ b/winsup/cygwin/release/3.3.4
@@ -30,3 +30,6 @@ Bug Fixes
 - Fix a problem creating a dir "foo", if a file (but not a Cygwin symlink)
   "foo.lnk" already exists.
   Addresses: https://github.com/msys2/msys2-runtime/issues/81
+
+- Fix double free for archetype, which is caused when open() fails.
+  Addresses: https://cygwin.com/pipermail/cygwin/2022-January/250518.html