Added 0001-ZEN-Add-sysctl-and-CONFIG-to-disallow-unprivileged-CLONE_NEWUSER.patch

3 files changed, 137 insertions, 4 deletions

diff --git a/.SRCINFO b/.SRCINFO
index 4942a8d5f115..53371c84bdfd 100644
--- a/.SRCINFO
+++ b/.SRCINFO
@@ -20,14 +20,14 @@ pkgbase = linux-xanmod-rt
 	source = https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.9.tar.sign
 	source = https://github.com/xanmod/linux/releases/download/5.9.0-rt16-xanmod2/patch-5.9.0-rt16-xanmod2.xz
 	source = choose-gcc-optimization.sh
-	source = 0001-ZEN-Add-sysctl-and-CONFIG-to-disallow-unprivileged-CLONE_NEWUSER.patch::https://aur.archlinux.org/cgit/aur.git/plain/0001-ZEN-Add-sysctl-and-CONFIG-to-disallow-unprivileged-C.patch?h=linux-ck&id=616ec1bb1f2c0fc42b6fb5c20995996897b4f43b
+	source = 0001-ZEN-Add-sysctl-and-CONFIG-to-disallow-unprivileged-CLONE_NEWUSER.patch
 	validpgpkeys = ABAF11C65A2970B130ABE3C479BE3E4300411886
 	validpgpkeys = 647F28654894E3BD457199BE38DBBDC86092693E
 	sha256sums = 3239a4ee1250bf2048be988cc8cb46c487b2c8a0de5b1b032d38394d5c6b1a06
 	sha256sums = SKIP
 	sha256sums = a94d0cadcb465a2b3021a772023951ea3a4d192d65e6fa0c2cfd9dd68dc62b5e
 	sha256sums = 2c7369218e81dee86f8ac15bda741b9bb34fa9cefcb087760242277a8207d511
-	sha256sums = 9c507bdb0062b5b54c6969f7da9ec18b259e06cd26dbe900cfe79a7ffb2713ee
+	sha256sums = 6c66dba73251440352f93ff32b72f5dd49536d0f17ef9347867660fd3a626991
 
 pkgname = linux-xanmod-rt
 	pkgdesc = The Linux kernel and modules with Xanmod patches
diff --git a/0001-ZEN-Add-sysctl-and-CONFIG-to-disallow-unprivileged-CLONE_NEWUSER.patch b/0001-ZEN-Add-sysctl-and-CONFIG-to-disallow-unprivileged-CLONE_NEWUSER.patch
new file mode 100644
index 000000000000..d7dee55dde5e
--- /dev/null
+++ b/0001-ZEN-Add-sysctl-and-CONFIG-to-disallow-unprivileged-CLONE_NEWUSER.patch
@@ -0,0 +1,133 @@
+From a8d736bad70d4062a14c29bdcbed71bef7b575f5 Mon Sep 17 00:00:00 2001
+From: "Jan Alexander Steffens (heftig)" <jan.steffens@gmail.com>
+Date: Mon, 16 Sep 2019 04:53:20 +0200
+Subject: [PATCH 01/15] 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 b4daad2bac23..362f82c5ec07 100644
+--- a/init/Kconfig
++++ b/init/Kconfig
+@@ -1118,6 +1118,22 @@ 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 755d8160e001..ed909f8050b2 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
+@@ -1779,6 +1784,10 @@ 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.
+@@ -2836,6 +2845,12 @@ 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 70665934d53e..9797869ed829 100644
+--- a/kernel/sysctl.c
++++ b/kernel/sysctl.c
+@@ -111,6 +111,10 @@
+ static int sixty = 60;
+ #endif
+ 
++#ifdef CONFIG_USER_NS
++extern int unprivileged_userns_clone;
++#endif
++
+ static int __maybe_unused neg_one = -1;
+ static int __maybe_unused two = 2;
+ static int __maybe_unused four = 4;
+@@ -1881,6 +1885,15 @@
+ 		.mode		= 0644,
+ 		.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
+ 	{
+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);
+ 
+-- 
+2.25.0
+
diff --git a/PKGBUILD b/PKGBUILD
index 179b7cb89f6b..7b8a242f1354 100644
--- a/PKGBUILD
+++ b/PKGBUILD
@@ -86,7 +86,7 @@ _srcname="linux-${pkgver}-rt${_rt}-xanmod${xanmod}"
 source=("https://cdn.kernel.org/pub/linux/kernel/v${_branch}/linux-${_major}.tar."{xz,sign}
         "https://github.com/xanmod/linux/releases/download/${pkgver}-rt${_rt}-xanmod${xanmod}/patch-${pkgver}-rt${_rt}-xanmod${xanmod}.xz"
         choose-gcc-optimization.sh
-        '0001-ZEN-Add-sysctl-and-CONFIG-to-disallow-unprivileged-CLONE_NEWUSER.patch::https://aur.archlinux.org/cgit/aur.git/plain/0001-ZEN-Add-sysctl-and-CONFIG-to-disallow-unprivileged-C.patch?h=linux-ck&id=616ec1bb1f2c0fc42b6fb5c20995996897b4f43b')
+        '0001-ZEN-Add-sysctl-and-CONFIG-to-disallow-unprivileged-CLONE_NEWUSER.patch')
 validpgpkeys=(
     'ABAF11C65A2970B130ABE3C479BE3E4300411886' # Linux Torvalds
     '647F28654894E3BD457199BE38DBBDC86092693E' # Greg Kroah-Hartman
@@ -103,7 +103,7 @@ sha256sums=('3239a4ee1250bf2048be988cc8cb46c487b2c8a0de5b1b032d38394d5c6b1a06'
             'SKIP'
             'a94d0cadcb465a2b3021a772023951ea3a4d192d65e6fa0c2cfd9dd68dc62b5e'
             '2c7369218e81dee86f8ac15bda741b9bb34fa9cefcb087760242277a8207d511'
-            '9c507bdb0062b5b54c6969f7da9ec18b259e06cd26dbe900cfe79a7ffb2713ee')
+            '6c66dba73251440352f93ff32b72f5dd49536d0f17ef9347867660fd3a626991')
 
 export KBUILD_BUILD_HOST=${KBUILD_BUILD_HOST:-archlinux}
 export KBUILD_BUILD_USER=${KBUILD_BUILD_USER:-makepkg}