Date: Thursday, March 5, 2020 @ 20:49:00
Author: anthraxx
Revision: 376802
upgpkg: linux-lts 5.4.24-1: add back
sysctl-and-CONFIG-for-unprivileged_userns_clone
Added:
linux-lts/trunk/0001-add-sysctl-and-CONFIG-for-unprivileged_userns_clone.patch
Modified:
linux-lts/trunk/PKGBUILD
linux-lts/trunk/config
----------------------------------------------------------------+
0001-add-sysctl-and-CONFIG-for-unprivileged_userns_clone.patch | 132
++++++++++
PKGBUILD | 8
config | 1
3 files changed, 138 insertions(+), 3 deletions(-)
Added: 0001-add-sysctl-and-CONFIG-for-unprivileged_userns_clone.patch
===================================================================
--- 0001-add-sysctl-and-CONFIG-for-unprivileged_userns_clone.patch
(rev 0)
+++ 0001-add-sysctl-and-CONFIG-for-unprivileged_userns_clone.patch
2020-03-05 20:49:00 UTC (rev 376802)
@@ -0,0 +1,132 @@
+From 6136ffb3d88e9f044260f8288d2d0a1edd64379e Mon Sep 17 00:00:00 2001
+From: "Jan Alexander Steffens (heftig)" <jan.steff...@gmail.com>
+Date: Mon, 16 Sep 2019 04:53:20 +0200
+Subject: [PATCH] ZEN: Add sysctl and CONFIG to disallow unprivileged
+ CLONE_NEWUSER
+
+Our default behavior continues to match the vanilla kernel.
+---
+ init/Kconfig | 16 ++++++++++++++++
+ kernel/fork.c | 15 +++++++++++++++
+ kernel/sysctl.c | 12 ++++++++++++
+ kernel/user_namespace.c | 7 +++++++
+ 4 files changed, 50 insertions(+)
+
+diff --git a/init/Kconfig b/init/Kconfig
+index bd7d650d4a99..658f9c052151 100644
+--- a/init/Kconfig
++++ b/init/Kconfig
+@@ -1091,6 +1091,22 @@ config USER_NS
+
+ If unsure, say N.
+
++config USER_NS_UNPRIVILEGED
++ bool "Allow unprivileged users to create namespaces"
++ default y
++ depends on USER_NS
++ help
++ When disabled, unprivileged users will not be able to create
++ new namespaces. Allowing users to create their own namespaces
++ has been part of several recent local privilege escalation
++ exploits, so if you need user namespaces but are
++ paranoid^Wsecurity-conscious you want to disable this.
++
++ This setting can be overridden at runtime via the
++ kernel.unprivileged_userns_clone sysctl.
++
++ If unsure, say Y.
++
+ config PID_NS
+ bool "PID Namespaces"
+ default y
+diff --git a/kernel/fork.c b/kernel/fork.c
+index 541fd805fb88..ffd57c812153 100644
+--- a/kernel/fork.c
++++ b/kernel/fork.c
+@@ -106,6 +106,11 @@
+
+ #define CREATE_TRACE_POINTS
+ #include <trace/events/task.h>
++#ifdef CONFIG_USER_NS
++extern int unprivileged_userns_clone;
++#else
++#define unprivileged_userns_clone 0
++#endif
+
+ /*
+ * Minimum number of threads to boot the kernel
+@@ -1788,6 +1793,10 @@ static __latent_entropy struct task_struct
*copy_process(
+ if ((clone_flags & (CLONE_NEWUSER|CLONE_FS)) ==
(CLONE_NEWUSER|CLONE_FS))
+ return ERR_PTR(-EINVAL);
+
++ if ((clone_flags & CLONE_NEWUSER) && !unprivileged_userns_clone)
++ if (!capable(CAP_SYS_ADMIN))
++ return ERR_PTR(-EPERM);
++
+ /*
+ * Thread groups must share signals as well, and detached threads
+ * can only be started up within the thread group.
+@@ -2819,6 +2828,12 @@ int ksys_unshare(unsigned long unshare_flags)
+ if (unshare_flags & CLONE_NEWNS)
+ unshare_flags |= CLONE_FS;
+
++ if ((unshare_flags & CLONE_NEWUSER) && !unprivileged_userns_clone) {
++ err = -EPERM;
++ if (!capable(CAP_SYS_ADMIN))
++ goto bad_unshare_out;
++ }
++
+ err = check_unshare_flags(unshare_flags);
+ if (err)
+ goto bad_unshare_out;
+diff --git a/kernel/sysctl.c b/kernel/sysctl.c
+index 078950d9605b..baead3605bbe 100644
+--- a/kernel/sysctl.c
++++ b/kernel/sysctl.c
+@@ -110,6 +110,9 @@ extern int core_uses_pid;
+ extern char core_pattern[];
+ extern unsigned int core_pipe_limit;
+ #endif
++#ifdef CONFIG_USER_NS
++extern int unprivileged_userns_clone;
++#endif
+ extern int pid_max;
+ extern int pid_max_min, pid_max_max;
+ extern int percpu_pagelist_fraction;
+@@ -545,6 +548,15 @@ static struct ctl_table kern_table[] = {
+ .proc_handler = proc_dointvec,
+ },
+ #endif
++#ifdef CONFIG_USER_NS
++ {
++ .procname = "unprivileged_userns_clone",
++ .data = &unprivileged_userns_clone,
++ .maxlen = sizeof(int),
++ .mode = 0644,
++ .proc_handler = proc_dointvec,
++ },
++#endif
+ #ifdef CONFIG_PROC_SYSCTL
+ {
+ .procname = "tainted",
+diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c
+index 8eadadc478f9..c36ecd19562c 100644
+--- a/kernel/user_namespace.c
++++ b/kernel/user_namespace.c
+@@ -21,6 +21,13 @@
+ #include <linux/bsearch.h>
+ #include <linux/sort.h>
+
++/* sysctl */
++#ifdef CONFIG_USER_NS_UNPRIVILEGED
++int unprivileged_userns_clone = 1;
++#else
++int unprivileged_userns_clone;
++#endif
++
+ static struct kmem_cache *user_ns_cachep __read_mostly;
+ static DEFINE_MUTEX(userns_state_mutex);
+
+--
+2.23.0
+
Modified: PKGBUILD
===================================================================
--- PKGBUILD 2020-03-05 19:46:49 UTC (rev 376801)
+++ PKGBUILD 2020-03-05 20:49:00 UTC (rev 376802)
@@ -1,7 +1,7 @@
# Maintainer: Andreas Radke <andy...@archlinux.org>
pkgbase=linux-lts
-pkgver=5.4.23
+pkgver=5.4.24
pkgrel=1
pkgdesc='LTS Linux'
url="https://www.kernel.org/";
@@ -16,6 +16,7 @@
source=(
https://www.kernel.org/pub/linux/kernel/v${pkgver%%.*}.x/${_srcname}.tar.{xz,sign}
config # the main kernel config file
+ 0001-add-sysctl-and-CONFIG-for-unprivileged_userns_clone.patch
)
validpgpkeys=(
'ABAF11C65A2970B130ABE3C479BE3E4300411886' # Linus Torvalds
@@ -22,9 +23,10 @@
'647F28654894E3BD457199BE38DBBDC86092693E' # Greg Kroah-Hartman
)
# https://www.kernel.org/pub/linux/kernel/v5.x/sha256sums.asc
-sha256sums=('3f28aacdf5deddfdf80bb949884699b96053a3548dc3434552d30dc0bc781eca'
+sha256sums=('7fa0ac784c78129beed43260a7a22a077f1041ac0e8e88647284d2cf7b1d7eb3'
'SKIP'
- 'c827e48f874470a5a76c73947ebe6ea4382ced4ce36272a166c2df8842d5d7de')
+ '7a58467b4cf628306a0048993f43508e5da39d8495801602b25b035372651697'
+ 'a13581d3c6dc595206e4fe7fcf6b542e7a1bdbe96101f0f010fc5be49f99baf2')
export KBUILD_BUILD_HOST=archlinux
export KBUILD_BUILD_USER=$pkgbase
Modified: config
===================================================================
--- config 2020-03-05 19:46:49 UTC (rev 376801)
+++ config 2020-03-05 20:49:00 UTC (rev 376802)
@@ -181,6 +181,7 @@
CONFIG_UTS_NS=y
CONFIG_IPC_NS=y
CONFIG_USER_NS=y
+CONFIG_USER_NS_UNPRIVILEGED=y
CONFIG_PID_NS=y
CONFIG_NET_NS=y
CONFIG_CHECKPOINT_RESTORE=y
