Add a comment about `kernel.unprivileged_userns_clone` sysctl in Debian

[kconfig-hardened-check.git] / kconfig_hardened_check / checks.py

diff --git a/kconfig_hardened_check/checks.py b/kconfig_hardened_check/checks.py
index 43a4c648bba53fed54727838f518e6b4ed616d3f..8e52fd8fc27e98cbaa0af8c4c92ecd35b0408a9f 100644 (file)
--- a/kconfig_hardened_check/checks.py
+++ b/kconfig_hardened_check/checks.py
@@ -16,7 +16,7 @@ This module contains knowledge for checks.
 #    kernel.perf_event_paranoid=2 (or 3 with a custom patch, see https://lwn.net/Articles/696216/)
 #    kernel.kexec_load_disabled=1
 #    kernel.yama.ptrace_scope=3
-#    user.max_user_namespaces=0
+#    user.max_user_namespaces=0 (for Debian, also see kernel.unprivileged_userns_clone)
 #    what about bpf_jit_enable?
 #    kernel.unprivileged_bpf_disabled=1
 #    net.core.bpf_jit_harden=2
@@ -36,6 +36,7 @@ This module contains knowledge for checks.
 #    dev.tty.legacy_tiocsti=0
 #    vm.mmap_rnd_bits=max (?)
 #    kernel.sysrq=0
+#    abi.vsyscall32 (any value except 2)
 #
 # Think of these boot params:
 #    module.sig_enforce=1
@@ -165,9 +166,9 @@ def add_kconfig_checks(l, arch):
     hardened_usercopy_is_set = KconfigCheck('self_protection', 'kspp', 'HARDENED_USERCOPY', 'y')
     l += [hardened_usercopy_is_set]
     l += [AND(KconfigCheck('self_protection', 'kspp', 'HARDENED_USERCOPY_FALLBACK', 'is not set'),
-              hardened_usercopy_is_set)]
+              hardened_usercopy_is_set)] # usercopy whitelist violations should be prohibited
     l += [AND(KconfigCheck('self_protection', 'kspp', 'HARDENED_USERCOPY_PAGESPAN', 'is not set'),
-              hardened_usercopy_is_set)]
+              hardened_usercopy_is_set)] # this debugging for HARDENED_USERCOPY is not needed for security
     l += [AND(KconfigCheck('self_protection', 'kspp', 'GCC_PLUGIN_LATENT_ENTROPY', 'y'),
               gcc_plugins_support_is_set)]
     l += [OR(KconfigCheck('self_protection', 'kspp', 'MODULE_SIG', 'y'),
@@ -545,6 +546,18 @@ def add_cmdline_checks(l, arch):
                  KconfigCheck('cut_attack_surface', 'clipos', 'X86_VSYSCALL_EMULATION', 'is not set'),
                  AND(KconfigCheck('cut_attack_surface', 'kspp', 'LEGACY_VSYSCALL_NONE', 'y'),
                      CmdlineCheck('cut_attack_surface', 'kspp', 'vsyscall', 'is not set')))]
+        l += [OR(CmdlineCheck('cut_attack_surface', 'my', 'vdso32', '1'),
+                 CmdlineCheck('cut_attack_surface', 'my', 'vdso32', '0'),
+                 AND(KconfigCheck('cut_attack_surface', 'kspp', 'COMPAT_VDSO', 'is not set'),
+                     CmdlineCheck('cut_attack_surface', 'my', 'vdso32', 'is not set')))] # the vdso32 parameter must not be 2
+    if arch == 'X86_32':
+        l += [OR(CmdlineCheck('cut_attack_surface', 'my', 'vdso32', '1'),
+                 CmdlineCheck('cut_attack_surface', 'my', 'vdso', '1'),
+                 CmdlineCheck('cut_attack_surface', 'my', 'vdso32', '0'),
+                 CmdlineCheck('cut_attack_surface', 'my', 'vdso', '0'),
+                 AND(KconfigCheck('cut_attack_surface', 'kspp', 'COMPAT_VDSO', 'is not set'),
+                     CmdlineCheck('cut_attack_surface', 'my', 'vdso32', 'is not set'),
+                     CmdlineCheck('cut_attack_surface', 'my', 'vdso', 'is not set')))] # the vdso and vdso32 parameters must not be 2
 
     # 'cut_attack_surface', 'grsec'
     # The cmdline checks compatible with the kconfig options disabled by grsecurity...