From 835a4fc42089d12b41bf1564844d7b518cc5e324 Mon Sep 17 00:00:00 2001
From: Brett Randall <javabrett@gmail.com>
Date: Thu, 27 Jan 2022 16:03:13 +1100
Subject: [PATCH 1/5] Ensure fd 0 stdin </dev/null is always inheritable.

When gunicorn --daemon daemonizes the process, prior to this change it was
noted that in the general case (without -R / --enable-stdio-inheritance), when fd 0
was replaced with /dev/null, the dup2 copy is skipped, and per PEP 446
"Make newly created file descriptors non-inheritable", the result was a stdio
fd </dev/null which was non-inheritable.  As a result, any launched subprocess
did not have an open 0/stdin fd, which can cause problems in some applications.

This change retains the behaviour of opening /dev/null with fd 0, but adds a call
to os.set_inheritable(..) to ensure the fd is inheritable.

The -R branch had different logic but has now been standardised with the general
case.  It was previously opening /dev/null as fd 3 and the dup2() copy made it
inheritable as fd 0.  This branch now applies the same logic: open as fd 0
(i.e. after close(0)), then set_inheritable.  As a result, an extra fd 3 </dev/null
previously left open is no longer left open.

Signed-off-by: Brett Randall <javabrett@gmail.com>
---
 gunicorn/util.py | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/gunicorn/util.py b/gunicorn/util.py
index a821e357..af414093 100644
--- a/gunicorn/util.py
+++ b/gunicorn/util.py
@@ -486,7 +486,10 @@ def daemonize(enable_stdio_inheritance=False):
             closerange(0, 3)
 
             fd_null = os.open(REDIRECT_TO, os.O_RDWR)
+            # PEP 446, make fd for /dev/null inheritable
+            os.set_inheritable(fd_null, True)
 
+            # expect fd_null to be always 0 here, but in-case not ...
             if fd_null != 0:
                 os.dup2(fd_null, 0)
 
@@ -494,13 +497,17 @@ def daemonize(enable_stdio_inheritance=False):
             os.dup2(fd_null, 2)
 
         else:
-            fd_null = os.open(REDIRECT_TO, os.O_RDWR)
-
             # Always redirect stdin to /dev/null as we would
             # never expect to need to read interactive input.
 
+            os.close(0)
+
+            fd_null = os.open(REDIRECT_TO, os.O_RDWR)
+            # PEP 446, make fd for /dev/null inheritable
+            os.set_inheritable(fd_null, True)
+
+            # expect fd_null to be always 0 here, but in-case not ...
             if fd_null != 0:
-                os.close(0)
                 os.dup2(fd_null, 0)
 
             # If stdout and stderr are still connected to

From eedc3a38b66b4c5a5ae975baefdc9894288294e4 Mon Sep 17 00:00:00 2001
From: Brett Randall <javabrett@gmail.com>
Date: Sun, 30 Jan 2022 17:58:52 +1100
Subject: [PATCH 2/5] Refactoring: common stdin </dev/null.

---
 gunicorn/util.py | 39 ++++++++++++++++-----------------------
 1 file changed, 16 insertions(+), 23 deletions(-)

diff --git a/gunicorn/util.py b/gunicorn/util.py
index af414093..d0d4d7ee 100644
--- a/gunicorn/util.py
+++ b/gunicorn/util.py
@@ -472,6 +472,19 @@ def daemonize(enable_stdio_inheritance=False):
 
         os.umask(0o22)
 
+        # Always redirect stdin to /dev/null as we would
+        # never expect to need to read interactive input.
+
+        os.close(0)
+
+        fd_null = os.open(REDIRECT_TO, os.O_RDWR)
+        # PEP 446, make fd for /dev/null inheritable
+        os.set_inheritable(fd_null, True)
+
+        # expect fd_null to be always 0 here, but in-case not ...
+        if fd_null != 0:
+            os.dup2(fd_null, 0)
+
         # In both the following any file descriptors above stdin
         # stdout and stderr are left untouched. The inheritance
         # option simply allows one to have output go to a file
@@ -479,37 +492,17 @@ def daemonize(enable_stdio_inheritance=False):
         # to use --error-log option.
 
         if not enable_stdio_inheritance:
-            # Remap all of stdin, stdout and stderr on to
+            # Remap remaining fds stdout and stderr on to
             # /dev/null. The expectation is that users have
             # specified the --error-log option.
 
-            closerange(0, 3)
-
-            fd_null = os.open(REDIRECT_TO, os.O_RDWR)
-            # PEP 446, make fd for /dev/null inheritable
-            os.set_inheritable(fd_null, True)
-
-            # expect fd_null to be always 0 here, but in-case not ...
-            if fd_null != 0:
-                os.dup2(fd_null, 0)
+            # 1/stdout, 2/stderr - 0/stdin already done above
+            closerange(1, 3)
 
             os.dup2(fd_null, 1)
             os.dup2(fd_null, 2)
 
         else:
-            # Always redirect stdin to /dev/null as we would
-            # never expect to need to read interactive input.
-
-            os.close(0)
-
-            fd_null = os.open(REDIRECT_TO, os.O_RDWR)
-            # PEP 446, make fd for /dev/null inheritable
-            os.set_inheritable(fd_null, True)
-
-            # expect fd_null to be always 0 here, but in-case not ...
-            if fd_null != 0:
-                os.dup2(fd_null, 0)
-
             # If stdout and stderr are still connected to
             # their original file descriptors we check to see
             # if they are associated with terminal devices.

From e9c4f7443ed5776baed3abc3e91ea61e7d82dda0 Mon Sep 17 00:00:00 2001
From: Brett Randall <javabrett@gmail.com>
Date: Mon, 31 Jan 2022 07:18:45 +1100
Subject: [PATCH 3/5] Revert "Refactoring: common stdin </dev/null."

This reverts commit a4f286769858ecfef14080f815adce26c260b2a9.
---
 gunicorn/util.py | 39 +++++++++++++++++++++++----------------
 1 file changed, 23 insertions(+), 16 deletions(-)

diff --git a/gunicorn/util.py b/gunicorn/util.py
index d0d4d7ee..af414093 100644
--- a/gunicorn/util.py
+++ b/gunicorn/util.py
@@ -472,19 +472,6 @@ def daemonize(enable_stdio_inheritance=False):
 
         os.umask(0o22)
 
-        # Always redirect stdin to /dev/null as we would
-        # never expect to need to read interactive input.
-
-        os.close(0)
-
-        fd_null = os.open(REDIRECT_TO, os.O_RDWR)
-        # PEP 446, make fd for /dev/null inheritable
-        os.set_inheritable(fd_null, True)
-
-        # expect fd_null to be always 0 here, but in-case not ...
-        if fd_null != 0:
-            os.dup2(fd_null, 0)
-
         # In both the following any file descriptors above stdin
         # stdout and stderr are left untouched. The inheritance
         # option simply allows one to have output go to a file
@@ -492,17 +479,37 @@ def daemonize(enable_stdio_inheritance=False):
         # to use --error-log option.
 
         if not enable_stdio_inheritance:
-            # Remap remaining fds stdout and stderr on to
+            # Remap all of stdin, stdout and stderr on to
             # /dev/null. The expectation is that users have
             # specified the --error-log option.
 
-            # 1/stdout, 2/stderr - 0/stdin already done above
-            closerange(1, 3)
+            closerange(0, 3)
+
+            fd_null = os.open(REDIRECT_TO, os.O_RDWR)
+            # PEP 446, make fd for /dev/null inheritable
+            os.set_inheritable(fd_null, True)
+
+            # expect fd_null to be always 0 here, but in-case not ...
+            if fd_null != 0:
+                os.dup2(fd_null, 0)
 
             os.dup2(fd_null, 1)
             os.dup2(fd_null, 2)
 
         else:
+            # Always redirect stdin to /dev/null as we would
+            # never expect to need to read interactive input.
+
+            os.close(0)
+
+            fd_null = os.open(REDIRECT_TO, os.O_RDWR)
+            # PEP 446, make fd for /dev/null inheritable
+            os.set_inheritable(fd_null, True)
+
+            # expect fd_null to be always 0 here, but in-case not ...
+            if fd_null != 0:
+                os.dup2(fd_null, 0)
+
             # If stdout and stderr are still connected to
             # their original file descriptors we check to see
             # if they are associated with terminal devices.

From 0b6939de86ba38e77200717d7f057af64e3f3b95 Mon Sep 17 00:00:00 2001
From: Brett Randall <javabrett@gmail.com>
Date: Mon, 31 Jan 2022 07:26:26 +1100
Subject: [PATCH 4/5] Undo changes that make -R branch logic behave the same as
 non -R branch, that is, to close(0) and open /dev/null as fd=0 instead of
 fd=3.

(Partially) Revert "Ensure fd 0 stdin </dev/null is always inheritable."

This partially reverts commit 7946678f271e25473618929d6f2725c8c375563e.
---
 gunicorn/util.py | 10 +++-------
 1 file changed, 3 insertions(+), 7 deletions(-)

diff --git a/gunicorn/util.py b/gunicorn/util.py
index af414093..fb844c18 100644
--- a/gunicorn/util.py
+++ b/gunicorn/util.py
@@ -497,17 +497,13 @@ def daemonize(enable_stdio_inheritance=False):
             os.dup2(fd_null, 2)
 
         else:
+            fd_null = os.open(REDIRECT_TO, os.O_RDWR)
+
             # Always redirect stdin to /dev/null as we would
             # never expect to need to read interactive input.
 
-            os.close(0)
-
-            fd_null = os.open(REDIRECT_TO, os.O_RDWR)
-            # PEP 446, make fd for /dev/null inheritable
-            os.set_inheritable(fd_null, True)
-
-            # expect fd_null to be always 0 here, but in-case not ...
             if fd_null != 0:
+                os.close(0)
                 os.dup2(fd_null, 0)
 
             # If stdout and stderr are still connected to

From 230cd0340346f2c08969f58e97c6435aeea34ae0 Mon Sep 17 00:00:00 2001
From: Brett Randall <javabrett@gmail.com>
Date: Mon, 7 Feb 2022 07:39:34 +1100
Subject: [PATCH 5/5] Updated THANKS.

---
 THANKS | 1 +
 1 file changed, 1 insertion(+)

diff --git a/THANKS b/THANKS
index 2b226f35..cc48fa5d 100644
--- a/THANKS
+++ b/THANKS
@@ -109,6 +109,7 @@ Kyle Mulka <repalviglator@yahoo.com>
 Lars Hansson <romabysen@gmail.com>
 Leonardo Santagada <santagada@gmail.com>
 Levi Gross <levi@levigross.com>
+licunlong <shenxiaogll@163.com>
 Łukasz Kucharski <lkucharski@leon.pl>
 Mahmoud Hashemi <mahmoudrhashemi@gmail.com>
 Malthe Borch <mborch@gmail.com>