fix CVE-2020-14019

Signed-off-by: Wenchao Hao <haowenchao@huawei.com>
This commit is contained in:
Wenchao Hao 2021-01-25 19:55:27 +08:00
parent 5d46c9e39d
commit 8ed9862012
4 changed files with 136 additions and 1 deletions

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@ -0,0 +1,53 @@
From b23d061ee0fa7924d2cdce6194c313b9ee06c468 Mon Sep 17 00:00:00 2001
From: Prasanna Kumar Kalever <prasanna.kalever@redhat.com>
Date: Thu, 28 May 2020 20:42:16 +0530
Subject: [PATCH] saveconfig: copy temp configfile with permissions
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
shutil.copyfile() will not copy permissions, so all the perms that we
set on tempfile will go for a toss, and will be reset to default
┌──────────────────┬────────┬───────────┬───────┬────────────────┐
│ Function │ Copies │ Copies │Can use│ Destination │
│ │metadata│permissions│buffer │may be directory│
├──────────────────┼────────┼───────────┼───────┼────────────────┤
│shutil.copy │ No │ Yes │ No │ Yes │
│shutil.copyfile │ No │ No │ No │ No │
│shutil.copy2 │ Yes │ Yes │ No │ Yes │
│shutil.copyfileobj│ No │ No │ Yes │ No │
└──────────────────┴────────┴───────────┴───────┴────────────────┘
Without this fix:
----------------
$ ls /etc/target/saveconfig.json -l
-rw-r--r-- 1 root root 5078 May 28 20:01 /etc/target/saveconfig.json
With this fix:
--------------
$ ls /etc/target/saveconfig.json -l
-rw------- 1 root root 5078 May 28 20:15 /etc/target/saveconfig.json
Signed-off-by: Prasanna Kumar Kalever <prasanna.kalever@redhat.com>
---
rtslib/root.py | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/rtslib/root.py b/rtslib/root.py
index a101edd..7364154 100644
--- a/rtslib/root.py
+++ b/rtslib/root.py
@@ -486,7 +486,8 @@ class RTSRoot(CFSNode):
os.fsync(f.fileno())
f.close()
- shutil.copyfile(tmp_file, save_file)
+ # copy along with permissions
+ shutil.copy(tmp_file, save_file)
os.remove(tmp_file)
def restore_from_file(self, restore_file=None, clear_existing=True,
--
1.8.3.1

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@ -0,0 +1,46 @@
From dffcf83bead64e959505d64ad587768647caab3a Mon Sep 17 00:00:00 2001
From: Prasanna Kumar Kalever <prasanna.kalever@redhat.com>
Date: Thu, 28 May 2020 19:53:04 +0530
Subject: [PATCH] saveconfig: open the temp configfile with modes set
Fixes: #161
Signed-off-by: Prasanna Kumar Kalever <prasanna.kalever@redhat.com>
---
rtslib/root.py | 21 +++++++++++++++++++--
1 file changed, 19 insertions(+), 2 deletions(-)
diff --git a/rtslib/root.py b/rtslib/root.py
index afe1a53..a101edd 100644
--- a/rtslib/root.py
+++ b/rtslib/root.py
@@ -461,8 +461,25 @@ class RTSRoot(CFSNode):
tmp_file = save_file + ".temp"
- with open(tmp_file, "w+") as f:
- os.fchmod(f.fileno(), stat.S_IRUSR | stat.S_IWUSR)
+ mode = stat.S_IRUSR | stat.S_IWUSR # 0o600
+ umask = 0o777 ^ mode # Prevents always downgrading umask to 0
+
+ # For security, remove file with potentially elevated mode
+ try:
+ os.remove(tmp_file)
+ except OSError:
+ pass
+
+ umask_original = os.umask(umask)
+ # Even though the old file is first deleted, a race condition is still
+ # possible. Including os.O_EXCL with os.O_CREAT in the flags will
+ # prevent the file from being created if it exists due to a race
+ try:
+ fdesc = os.open(tmp_file, os.O_WRONLY | os.O_CREAT | os.O_EXCL, mode)
+ finally:
+ os.umask(umask_original)
+
+ with os.fdopen(fdesc, 'w+') as f:
f.write(json.dumps(saveconf, sort_keys=True, indent=2))
f.write("\n")
f.flush()
--
1.8.3.1

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@ -0,0 +1,29 @@
From fc7c15f882d800cc7bce03936dfec7c5b7cd13bf Mon Sep 17 00:00:00 2001
From: Prasanna Kumar Kalever <prasanna.kalever@redhat.com>
Date: Tue, 9 Jun 2020 11:47:42 +0530
Subject: [PATCH 10/15] save_to_file: fix fd open mode
since we used O_WRONLY with os.open(), lets stick to
same mode with os.fdopen() too
Signed-off-by: Prasanna Kumar Kalever <prasanna.kalever@redhat.com>
---
rtslib/root.py | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/rtslib/root.py b/rtslib/root.py
index 3135467..2c5cf43 100644
--- a/rtslib/root.py
+++ b/rtslib/root.py
@@ -479,7 +479,7 @@ class RTSRoot(CFSNode):
finally:
os.umask(umask_original)
- with os.fdopen(fdesc, 'w+') as f:
+ with os.fdopen(fdesc, 'w') as f:
f.write(json.dumps(saveconf, sort_keys=True, indent=2))
f.write("\n")
f.flush()
--
2.27.0

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@ -2,13 +2,17 @@
Name: python-rtslib
Version: 2.1.70
Release: 4
Release: 5
Summary: Python object API for Linux kernel LIO SCSI target
License: ASL 2.0
URL: https://github.com/open-iscsi/%{oname}
Source0: %{url}/archive/v%{version}/%{oname}-%{version}.tar.gz
Patch1: 0001-saveconfig-copy-temp-configfile-with-permissions.patch
Patch2: 0002-saveconfig-open-the-temp-configfile-with-modes-set.patch
Patch3: 0003-save_to_file-fix-fd-open-mode.patch
BuildArch: noarch
BuildRequires: systemd
Requires(post): systemd
@ -91,6 +95,9 @@ install -m 644 doc/saveconfig.json.5 %{buildroot}%{_mandir}/man5/
%{_mandir}/man5/saveconfig.json.5*
%changelog
* Mon Jan 25 2020 Wenchao Hao <haowenchao@huawei.com> - 2.1.70-5
- fix CVE-2020-14019
* Thu Jan 07 2021 Lixiaokeng <lixiaokeng@huawei.com> - 2.1.70-4
- python2-kmod is removed and required by python2-rtslib. Remove python2-rtslib.