From: Simon Ruderich <simon@ruderich.org>
Date: Wed, 28 Feb 2024 11:42:54 +0000 (+0100)
Subject: Support branch protection
X-Git-Tag: 0.14~1
X-Git-Url: https://ruderich.org/simon/gitweb/?p=blhc%2Fblhc.git;a=commitdiff_plain;h=019d2b1c80b43bc7fa2a1df68ca3fa4f81569961

Support branch protection
---

diff --git a/NEWS b/NEWS
index 5906b26..1e0944e 100644
--- a/NEWS
+++ b/NEWS
@@ -20,6 +20,9 @@ Version 0.XX
   (Debian Bugs #1043522 and #1054882).
 - Check for stack clash protection (-fstack-clash-protection); requested by
   Emanuele Rocca (Debian Bug #1050909).
+- Check for branch protection (amd64: -fcf-protection, arm64:
+  -mbranch-protection=standard); requested by Emanuele Rocca (Debian Bug
+  #1050912).
 
 
 Version 0.13
diff --git a/bin/blhc b/bin/blhc
index c444383..9b785b1 100755
--- a/bin/blhc
+++ b/bin/blhc
@@ -243,6 +243,12 @@ my @def_cflags_stack_clash = (
 my @def_cflags_pie = (
     '-fPIE',
 );
+my @def_cflags_branch_amd64 = (
+    '-fcf-protection',
+);
+my @def_cflags_branch_arm64 = (
+    '-mbranch-protection=standard',
+);
 my @def_cxxflags = (
     @def_cflags,
 );
@@ -285,6 +291,8 @@ my @flag_refs = (
     \@def_cflags_stack_bad,
     \@def_cflags_stack_clash,
     \@def_cflags_pie,
+    \@def_cflags_branch_amd64,
+    \@def_cflags_branch_arm64,
     \@def_cxxflags,
     \@def_cppflags,
     \@def_cppflags_fortify,
@@ -807,6 +815,7 @@ foreach my $file (@ARGV) {
     my $harden_stack   = 1;
     my $harden_stack_strong = 1;
     my $harden_stack_clash = 1;
+    my $harden_branch  = 1;
     my $harden_relro   = 1;
     my $harden_bindnow = $option_bindnow; # defaults to 0
     my $harden_pie     = $option_pie;     # defaults to 0
@@ -862,6 +871,7 @@ foreach my $file (@ARGV) {
             my $disable = 1;
             my $disable_strong = 1;
             my $disable_clash = 1;
+            my $disable_branch = 1;
 
             if ($line =~ /\bdpkg-dev_(\S+)/) {
                 if (Dpkg::Version::version_compare($1, '1.16.1') >= 0) {
@@ -875,6 +885,7 @@ foreach my $file (@ARGV) {
                 }
                 if (Dpkg::Version::version_compare($1, '1.22.0') >= 0) {
                     $disable_clash = 0;
+                    $disable_branch = 0;
                 }
             }
 
@@ -892,6 +903,9 @@ foreach my $file (@ARGV) {
             if ($disable_clash) {
                 $harden_stack_clash = 0;
             }
+            if ($disable_branch) {
+                $harden_branch = 0;
+            }
         }
 
         # The following two versions of CMake in Debian obeyed CPPFLAGS, but
@@ -1179,6 +1193,7 @@ foreach my $file (@ARGV) {
     }
 
     # Option or auto detected.
+    my @harden_branch_flags;
     if ($arch) {
         # The following was partially copied from dpkg-dev 1.22.0
         # (/usr/share/perl5/Dpkg/Vendor/Debian.pm, set_build_features and
@@ -1248,6 +1263,11 @@ foreach my $file (@ARGV) {
             $harden_relro   = 0;
             $harden_bindnow = 0;
         }
+        if ($cpu eq 'amd64') {
+            @harden_branch_flags = @def_cflags_branch_amd64;
+        } elsif ($cpu eq 'arm64') {
+            @harden_branch_flags = @def_cflags_branch_arm64;
+        }
     }
 
     # Default values.
@@ -1281,6 +1301,10 @@ foreach my $file (@ARGV) {
         @cflags   = (@cflags,   @def_cflags_format);
         @cxxflags = (@cxxflags, @def_cflags_format);
     }
+    if ($harden_branch and @harden_branch_flags) {
+        @cflags   = (@cflags,   @harden_branch_flags);
+        @cxxflags = (@cxxflags, @harden_branch_flags);
+    }
     if ($harden_relro) {
         @ldflags = (@ldflags, @def_ldflags_relro);
     }
diff --git a/t/logs/arch-amd64 b/t/logs/arch-amd64
index f985d87..7719629 100644
--- a/t/logs/arch-amd64
+++ b/t/logs/arch-amd64
@@ -3,7 +3,7 @@ dpkg-buildpackage: host architecture amd64
 
 # all hardening options
 
-gcc -D_FORTIFY_SOURCE=2 -g -O2 -fPIE -fstack-protector-strong -fstack-clash-protection -Wformat -Wformat-security -Werror=format-security -Wall -c test.c
+gcc -D_FORTIFY_SOURCE=2 -g -O2 -fPIE -fcf-protection -fstack-protector-strong -fstack-clash-protection -Wformat -Wformat-security -Werror=format-security -Wall -c test.c
 gcc -fPIE -pie -Wl,-z,relro -Wl,-z,now -o test test.o
 
 # missing flags
diff --git a/t/logs/debian-gcc-pie b/t/logs/debian-gcc-pie
index 132f9d3..0d46d28 100644
--- a/t/logs/debian-gcc-pie
+++ b/t/logs/debian-gcc-pie
@@ -1,5 +1,5 @@
 dpkg-buildpackage: source package foo package
 dpkg-buildpackage: host architecture amd64
 
-gcc -g -O2 -D_FORTIFY_SOURCE=2 -Wl,-z,relro -Wl,-z,now -fstack-protector-strong -fstack-clash-protection -Wformat -Werror=format-security -o test test.c
-gcc -fPIE -pie -g -O2 -D_FORTIFY_SOURCE=2 -Wl,-z,relro -Wl,-z,now -fstack-protector-strong -fstack-clash-protection -Wformat -Werror=format-security -o test test.c
+gcc -g -O2 -D_FORTIFY_SOURCE=2 -Wl,-z,relro -Wl,-z,now -fcf-protection -fstack-protector-strong -fstack-clash-protection -Wformat -Werror=format-security -o test test.c
+gcc -fPIE -pie -g -O2 -D_FORTIFY_SOURCE=2 -Wl,-z,relro -Wl,-z,now -fcf-protection -fstack-protector-strong -fstack-clash-protection -Wformat -Werror=format-security -o test test.c
diff --git a/t/tests.t b/t/tests.t
index 9ae22b0..5d9eb9b 100644
--- a/t/tests.t
+++ b/t/tests.t
@@ -104,7 +104,7 @@ is_blhc 'empty', '', 1,
 # ANSI colored output.
 
 is_blhc 'arch-amd64', '--color', 8,
-        "\033[31mCFLAGS missing\033[0m (-fstack-protector-strong)\033[33m:\033[0m gcc -D_FORTIFY_SOURCE=2 -g -O2 -fPIE -fstack-clash-protection -Wformat -Wformat-security -Werror=format-security -Wall -c test.c
+        "\033[31mCFLAGS missing\033[0m (-fstack-protector-strong -fcf-protection)\033[33m:\033[0m gcc -D_FORTIFY_SOURCE=2 -g -O2 -fPIE -fstack-clash-protection -Wformat -Wformat-security -Werror=format-security -Wall -c test.c
 \033[31mLDFLAGS missing\033[0m (-pie)\033[33m:\033[0m gcc -fPIE -Wl,-z,relro -Wl,-z,now -o test test.o
 ";
 
@@ -1101,7 +1101,7 @@ is_blhc ['arch-i386', 'arch-amd64', 'arch-hppa', 'ignore-flag'],
         "checking './t/logs/arch-i386'...
 LDFLAGS missing (-pie): gcc -fPIE -Wl,-z,relro -Wl,-z,now -o test test.o
 checking './t/logs/arch-amd64'...
-CFLAGS missing (-fstack-protector-strong): gcc -D_FORTIFY_SOURCE=2 -g -O2 -fPIE -fstack-clash-protection -Wformat -Wformat-security -Werror=format-security -Wall -c test.c
+CFLAGS missing (-fstack-protector-strong -fcf-protection): gcc -D_FORTIFY_SOURCE=2 -g -O2 -fPIE -fstack-clash-protection -Wformat -Wformat-security -Werror=format-security -Wall -c test.c
 LDFLAGS missing (-pie): gcc -fPIE -Wl,-z,relro -Wl,-z,now -o test test.o
 checking './t/logs/arch-hppa'...
 checking './t/logs/ignore-flag'...
@@ -1115,7 +1115,7 @@ is_blhc ['arch-i386', 'arch-amd64', 'arch-hppa', 'ignore-line'],
         "checking './t/logs/arch-i386'...
 LDFLAGS missing (-pie): gcc -fPIE -Wl,-z,relro -Wl,-z,now -o test test.o
 checking './t/logs/arch-amd64'...
-CFLAGS missing (-fstack-protector-strong): gcc -D_FORTIFY_SOURCE=2 -g -O2 -fPIE -fstack-clash-protection -Wformat -Wformat-security -Werror=format-security -Wall -c test.c
+CFLAGS missing (-fstack-protector-strong -fcf-protection): gcc -D_FORTIFY_SOURCE=2 -g -O2 -fPIE -fstack-clash-protection -Wformat -Wformat-security -Werror=format-security -Wall -c test.c
 LDFLAGS missing (-pie): gcc -fPIE -Wl,-z,relro -Wl,-z,now -o test test.o
 checking './t/logs/arch-hppa'...
 checking './t/logs/ignore-line'...