[patch] Patch

portage.patch (text/plain), 3.79 KB, created by Arfrever Frehtes Taifersar Arahesis on 2019-01-21 16:22:37 UTC

From 3192c6636c7492a6a1ed5650f8368464fac040e4 Mon Sep 17 00:00:00 2001
From: Arfrever Frehtes Taifersar Arahesis <[e-mail]>
Date: Mon, 21 Jan 2019 17:14:03 +0100
Subject: [PATCH] pid-ns-init: Drop permissions only for subprocess of
 pid-ns-init but not pid-ns-init itself

With FEATURES="pid-sandbox userpriv", pid-ns-init should be run with unchanged
permissions (usually UID=0, GID=0).

Bug: https://bugs.gentoo.org/675868
Signed-off-by: Arfrever Frehtes Taifersar Arahesis <[e-mail]>
---
 bin/pid-ns-init        | 26 +++++++++++++++++++++++---
 lib/portage/process.py | 12 ++++++++++--
 2 files changed, 33 insertions(+), 5 deletions(-)

diff --git a/bin/pid-ns-init b/bin/pid-ns-init
index f9b8cc4f3..d66a8d510 100644
--- a/bin/pid-ns-init
+++ b/bin/pid-ns-init
@@ -39,7 +39,7 @@ def forward_kill_signal(main_child_pid, signum, frame):
 
 def main(argv):
 	if len(argv) < 2:
-		return 'Usage: {} <main-child-pid> or <pass_fds> <binary> <argv0> [arg]..'.format(argv[0])
+		return 'Usage: {} <main-child-pid> or <uid> <gid> <groups> <umask> <pass_fds> <binary> <argv0> [arg]..'.format(argv[0])
 
 	if len(argv) == 2:
 		# The child process is init (pid 1) in a child pid namespace, and
@@ -50,13 +50,33 @@ def main(argv):
 		proc = None
 	else:
 		# The current process is init (pid 1) in a child pid namespace.
-		pass_fds, binary, args = tuple(int(fd) for fd in argv[1].split(',')), argv[2], argv[3:]
+		uid, gid, groups, umask, pass_fds, binary, args = argv[1], argv[2], argv[3], argv[4], tuple(int(fd) for fd in argv[5].split(',')), argv[6], argv[7:]
+		if uid:
+			uid = int(uid)
+		if gid:
+			gid = int(gid)
+		if groups:
+			groups = tuple(int(group) for group in groups.split(','))
+		if umask:
+			umask = int(umask)
+
+		def preexec():
+			if gid:
+				os.setgid(gid)
+			if groups:
+				os.setgroups(groups)
+			if uid:
+				os.setuid(uid)
+			if umask:
+				os.umask(umask)
+			if signal_disposition_preexec is not None:
+				signal_disposition_preexec()
 
 		popen_kwargs = {}
 		if sys.version_info.major > 2:
 			popen_kwargs['pass_fds'] = pass_fds
 		proc = subprocess.Popen(args, executable=binary,
-			preexec_fn=signal_disposition_preexec, **popen_kwargs)
+			preexec_fn=preexec, **popen_kwargs)
 		main_child_pid = proc.pid
 
 	sig_handler = functools.partial(forward_kill_signal, main_child_pid)
diff --git a/lib/portage/process.py b/lib/portage/process.py
index dd3d58ddc..86b25226f 100644
--- a/lib/portage/process.py
+++ b/lib/portage/process.py
@@ -1,5 +1,5 @@
 # portage.py -- core Portage functionality
-# Copyright 1998-2018 Gentoo Authors
+# Copyright 1998-2019 Gentoo Authors
 # Distributed under the terms of the GNU General Public License v2
 
 
@@ -467,7 +467,7 @@ def _exec(binary, mycommand, opt_name, fd_pipes,
 	@param gid: Group ID to run the process under
 	@type gid: Integer
 	@param groups: Groups the Process should be in.
-	@type groups: Integer
+	@type groups: List
 	@param uid: User ID to run the process under
 	@type uid: Integer
 	@param umask: an int representing a unix umask (see man chmod for umask details)
@@ -571,8 +571,16 @@ def _exec(binary, mycommand, opt_name, fd_pipes,
 									portage._python_interpreter,
 									os.path.join(portage._bin_path,
 										'pid-ns-init'),
+									_unicode_encode(str(uid) if uid is not None else ''),
+									_unicode_encode(str(gid) if gid is not None else ''),
+									_unicode_encode(','.join(str(group) for group in groups) if groups is not None else ''),
+									_unicode_encode(str(umask) if umask is not None else ''),
 									_unicode_encode(','.join(str(fd) for fd in fd_pipes)),
 									binary] + myargs
+								uid = None
+								gid = None
+								groups = None
+								umask = None
 							else:
 								# Execute a supervisor process which will forward
 								# signals to init and forward exit status to the
-- 
2.20.1