diff --git a/.SRCINFO b/.SRCINFO index 4ac38bd..2cf211e 100644 --- a/.SRCINFO +++ b/.SRCINFO @@ -1,7 +1,7 @@ pkgbase = linux-clear pkgdesc = Clear Linux pkgver = 5.6.14 - pkgrel = 1 + pkgrel = 2 url = https://github.com/clearlinux-pkgs/linux arch = x86_64 license = GPL2 @@ -18,6 +18,7 @@ pkgbase = linux-clear source = clearlinux::git+https://github.com/clearlinux-pkgs/linux.git#tag=5.6.14-955 source = enable_additional_cpu_optimizations_for_gcc_v10.1+_kernel_v5.4-5.6_v1.patch source = pci-enable-overrides-for-missing-acs-capabilities.patch + source = 0001-ZEN-Add-sysctl-and-CONFIG-to-disallow-unprivileged-C.patch validpgpkeys = ABAF11C65A2970B130ABE3C479BE3E4300411886 validpgpkeys = 647F28654894E3BD457199BE38DBBDC86092693E sha256sums = e342b04a2aa63808ea0ef1baab28fc520bd031ef8cf93d9ee4a31d4058fcb622 @@ -26,6 +27,7 @@ pkgbase = linux-clear sha256sums = SKIP sha256sums = c650fc6ff773e99dbc1fda9411b10b06513c5161791106c44d5a11dbcf6420f9 sha256sums = 2c98de0814366b041aeee4cbf82b82620c7834bc33752d50f089e8bd7ea5cf5e + sha256sums = bdd05caf94135898bceac0a9d14ec6b1b458dba162d00efd46a292fe97f2679b pkgname = linux-clear pkgdesc = The Clear Linux kernel and modules diff --git a/0001-ZEN-Add-sysctl-and-CONFIG-to-disallow-unprivileged-C.patch b/0001-ZEN-Add-sysctl-and-CONFIG-to-disallow-unprivileged-C.patch new file mode 100644 index 0000000..29abaac --- /dev/null +++ b/0001-ZEN-Add-sysctl-and-CONFIG-to-disallow-unprivileged-C.patch @@ -0,0 +1,132 @@ +From f4b254de5d2b75143dd7c225e58afb3f5ee3bae6 Mon Sep 17 00:00:00 2001 +From: "Jan Alexander Steffens (heftig)" +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 6db3e310a5e4..2dd7dd1b6b0d 100644 +--- a/init/Kconfig ++++ b/init/Kconfig +@@ -1083,6 +1083,22 @@ 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 9180f4416dba..a02f83b1d9b4 100644 +--- a/kernel/fork.c ++++ b/kernel/fork.c +@@ -106,6 +106,11 @@ + + #define CREATE_TRACE_POINTS + #include ++#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. +@@ -2837,6 +2846,12 @@ 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 +@@ -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; +@@ -546,6 +549,15 @@ 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 + #include + ++/* 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); + +-- +2.26.2 + diff --git a/PKGBUILD b/PKGBUILD index c3f66d6..6fa3672 100644 --- a/PKGBUILD +++ b/PKGBUILD @@ -71,7 +71,7 @@ _srcname=linux-${_major} _clr=${_major}.14-955 pkgbase=linux-clear pkgver=${_major}.${_minor} -pkgrel=1 +pkgrel=2 pkgdesc='Clear Linux' arch=('x86_64') url="https://github.com/clearlinux-pkgs/linux" @@ -85,6 +85,7 @@ source=( "clearlinux::git+https://github.com/clearlinux-pkgs/linux.git#tag=${_clr}" 'enable_additional_cpu_optimizations_for_gcc_v10.1+_kernel_v5.4-5.6_v1.patch' 'pci-enable-overrides-for-missing-acs-capabilities.patch' + '0001-ZEN-Add-sysctl-and-CONFIG-to-disallow-unprivileged-C.patch' ) export KBUILD_BUILD_HOST=archlinux @@ -115,6 +116,10 @@ prepare() { echo "Applying pci-enable-overrides-for-missing-acs-capabilities.patch ..." patch -Np1 -i "$srcdir/pci-enable-overrides-for-missing-acs-capabilities.patch" + ### disable USER_NS for non-root users by default + echo "Applying 0001-ZEN-Add-sysctl-and-CONFIG-to-disallow-unprivileged-C.patch ..." + patch -Np1 -i "$srcdir/0001-ZEN-Add-sysctl-and-CONFIG-to-disallow-unprivileged-C.patch" + ### Setting config echo "Setting config..." cp -Tf $srcdir/clearlinux/config ./.config @@ -345,7 +350,8 @@ sha256sums=('e342b04a2aa63808ea0ef1baab28fc520bd031ef8cf93d9ee4a31d4058fcb622' '07e737cfdc79382dc259c4844a150d8d72ebbcdc9d7e03a9503f8f8e19f1aea4' 'SKIP' 'c650fc6ff773e99dbc1fda9411b10b06513c5161791106c44d5a11dbcf6420f9' - '2c98de0814366b041aeee4cbf82b82620c7834bc33752d50f089e8bd7ea5cf5e') + '2c98de0814366b041aeee4cbf82b82620c7834bc33752d50f089e8bd7ea5cf5e' + 'bdd05caf94135898bceac0a9d14ec6b1b458dba162d00efd46a292fe97f2679b') validpgpkeys=( 'ABAF11C65A2970B130ABE3C479BE3E4300411886' # Linus Torvalds