opnsense-src/tools
Alexander Leidinger 2a44cccd40 Add option to clear caller-used registers on function return.
The WITH_ZEROREGS option for src.conf will zero caller-used register
contents just before returning from a function, ensuring that
temporary values are not leaked beyond the function boundary. This
means that register contents are less likely to be available for side
channel attacks and information exposures.

It reduces all except 1 of the simple "write-what-where" ROP gadgets in
/lib:
    grep "Gadget found" /tmp/before_lib* | wc -l
     197
    grep "Gadget found" /tmp/after_lib* | wc -l
       1
    grep "Gadget found" /tmp/after_lib*
    /tmp/after_libbsdxml.so.4.txt:  [+] Gadget found: 0x1b3f1 mov qword ptr [rdi], rcx ; pop rbp ; ret

To reproduce:
    for lib in *.so.*; do
        echo $lib:
        ROPgadget --ropchain --binary /tmp/be_mount.Sx87/lib/$lib | sed -n '/Step 1/,/Step 2/p' >! /tmp/before_$lib.txt
        ROPgadget --ropchain --binary $lib | sed -n '/Step 1/,/Step 2/p' >!  /tmp/after_$lib.txt
    done

Additionally, in some cases this reduces the number of all ROP gadgets
(quick check with /libs only):
libalias.so.7: reduction 10.000%
libavl.so.2: reduction 13.900%
libbsdxml.so.4: reduction 37.500%
libc.so.7: reduction 10.000%
libc++.so.1: reduction 14.800%
libcam.so.7: reduction 50.700%
libcap_netdb.so.1: reduction 5.800%
libcasper.so.1: reduction 14.600%
libcrypto.so.30: reduction 7.500%
libdtrace.so.2: reduction 3.900%
libelf.so.2: reduction 15.800%
libgcc_s.so.1: reduction 32.700%
libibverbs.so.1: reduction 5.300%
libicp.so.3: reduction 2.100%
libipt.so.0: reduction 28.200%
libirdma.so.1: reduction 1.600%
libkiconv.so.4: reduction 0%
libm.so.5: reduction 21.900%
libmd.so.6: reduction 0%
libmd.so.7: reduction 3.100%
libncursesw.so.9: reduction 11.200%
libnvpair.so.2: reduction 40.200%
libpcap.so.8: reduction 11.400%
libpjdlog.so.0: reduction 27.400%
libsbuf.so.6: reduction 2.900%
libspl.so.2: reduction 42.300%
libsys.so.7: reduction 2.700%
libthr.so.3: reduction 21.000%
libuutil.so.2: reduction 13.100%
libz.so.6: reduction 5.600%
libzpool.so.2: reduction 15.100%

In some cases it adds some ROP gadgets despite removing the simple ROP
gadgets:
lib80211.so.1: reduction -32.700%
libbe.so.1: reduction -22.300%
libbegemot.so.4: reduction -20.500%
libcap_dns.so.2: reduction -58.000%
libcap_fileargs.so.1: reduction -28.200%
libcap_grp.so.1: reduction -54.000%
libcap_net.so.1: reduction -28.800%
libcap_pwd.so.1: reduction -38.800%
libcap_sysctl.so.2: reduction -71.100%
libcap_syslog.so.1: reduction -15.000%
libcrypt.so.5: reduction -14.600%
libctf.so.2: reduction -.300%
libcxxrt.so.1: reduction -14.000%
libdevstat.so.7: reduction -1.600%
libedit.so.8: reduction -4.200%
libgeom.so.5: reduction -16.500%
libicp_rescue.so.3: reduction -2.300%
libipsec.so.4: reduction -31.800%
libjail.so.1: reduction -21.700%
libkvm.so.7: reduction -5.300%
libmlx5.so.1: reduction -6.300%
libmt.so.5: reduction -23.000%
libnv.so.1: reduction -.400%
librss.so.1: reduction -3.800%
librt.so.1: reduction -24.000%
libssp.so.0: reduction -21.100%
libstats.so.0: reduction -9.000%
libtinfow.so.9: reduction -3.500%
libtpool.so.2: reduction -36.500%
libufs.so.8: reduction -11.900%
libulog.so.0: reduction -67.400%
libumem.so.2: reduction -2.000%
libutil.so.9: reduction -7.200%
libxo.so.0: reduction -9.000%
libzdb.so.2: reduction -11.700%
libzfs_core.so.2: reduction -17.700%
libzfs.so.4: reduction -.300%
libzfsbootenv.so.1: reduction -26.900%
libzutil.so.2: reduction -5.600%

To reproduce:
    for lib in *.so.*; do
        echo -n $lib:
        before="$(ROPgadget --nosys --nojop --binary /tmp/be_mount.Sx87/lib/$lib | tail -n1 | cut -d : -f 2)"
        after="$(ROPgadget --nosys --nojop --binary $lib | tail -n1 | cut -d : -f 2)"
        echo " reduction" $(bc -S 3 -e "(1-${after}/${before})*100")%
    done >/tmp/reduction.txt

Most of the time the size difference is very small (<1% for >50% of the
files and >10% for only 2 files):
lib80211.so.1: size change .100%
libalias.so.7: size change 0%
libavl.so.2: size change 0%
libbe.so.1: size change .100%
libbegemot.so.4: size change .100%
libbsdxml.so.4: size change 0%
libc.so.7: size change 1.200%
libc++.so.1: size change 1.600%
libcam.so.7: size change 1.900%
libcap_dns.so.2: size change .100%
libcap_fileargs.so.1: size change .100%
libcap_grp.so.1: size change .100%
libcap_net.so.1: size change .100%
libcap_netdb.so.1: size change .100%
libcap_pwd.so.1: size change .100%
libcap_sysctl.so.2: size change .100%
libcap_syslog.so.1: size change .100%
libcasper.so.1: size change 0%
libcrypt.so.5: size change 3.900%
libcrypto.so.30: size change 1.400%
libctf.so.2: size change .100%
libcxxrt.so.1: size change .100%
libdevstat.so.7: size change 15.400%		exceptional
libdtrace.so.2: size change .600%
libedit.so.8: size change 1.800%
libelf.so.2: size change .100%
libgcc_s.so.1: size change 3.000%
libgeom.so.5: size change 0%
libibverbs.so.1: size change .100%
libicp_rescue.so.3: size change .100%
libicp.so.3: size change 1.500%
libipsec.so.4: size change .100%
libipt.so.0: size change 3.100%
libirdma.so.1: size change .100%
libjail.so.1: size change .100%
libkiconv.so.4: size change .100%
libkvm.so.7: size change .100%
libm.so.5: size change 1.700%
libmd.so.6: size change 0%
libmd.so.7: size change .100%
libmlx5.so.1: size change 0%
libmt.so.5: size change .100%
libncursesw.so.9: size change 1.900%
libnv.so.1: size change 4.300%
libnvpair.so.2: size change 4.300%
libpcap.so.8: size change 1.200%
libpjdlog.so.0: size change .100%
librss.so.1: size change .200%
librt.so.1: size change .100%
libsbuf.so.6: size change .100%
libspl.so.2: size change 0%
libssp.so.0: size change .100%
libstats.so.0: size change .100%
libsys.so.7: size change .100%
libthr.so.3: size change 2.400%
libtinfow.so.9: size change 1.600%
libtpool.so.2: size change .100%
libufs.so.8: size change .100%
libulog.so.0: size change .100%
libumem.so.2: size change 54.300%		exceptional
libutil.so.9: size change .100%
libuutil.so.2: size change .100%
libxo.so.0: size change .100%
libz.so.6: size change .100%
libzdb.so.2: size change .300%
libzfs_core.so.2: size change .100%
libzfs.so.4: size change 2.000%
libzfsbootenv.so.1: size change .100%
libzpool.so.2: size change 1.200%
libzutil.so.2: size change 0%
2025-01-22 19:33:23 +01:00
..
boot Copy the new ia32 loader 2024-09-20 08:45:10 -06:00
bsdbox Remove residual blank line at start of Makefile 2024-07-15 16:43:39 -06:00
build Add option to clear caller-used registers on function return. 2025-01-22 19:33:23 +01:00
bus_space Remove residual blank line at start of Makefile 2024-07-15 16:43:39 -06:00
coccinelle copystr(9): Move to deprecate (attempt #2) 2020-05-25 16:40:48 +00:00
debugscripts Remove $FreeBSD$: one-line bare tag 2023-08-16 11:55:20 -06:00
diag Remove residual blank line at start of Makefile 2024-07-15 16:43:39 -06:00
ifnet Remove $FreeBSD$: one-line sh pattern 2023-08-16 11:55:03 -06:00
kerneldoc Remove SOC FPGA drivers 2024-12-06 17:38:52 -05:00
LibraryReport Remove $FreeBSD$: one-line sh pattern 2023-08-16 11:55:03 -06:00
lua Remove $FreeBSD$: one-line lua tag 2023-08-16 11:55:34 -06:00
pkgbase Remove $FreeBSD$: one-line lua tag 2023-08-16 11:55:34 -06:00
regression Remove "All Rights Reserved" from FreeBSD Foundation copyrights 2024-07-30 12:16:36 -04:00
sched Remove $FreeBSD$: one-line sh pattern 2023-08-16 11:55:03 -06:00
test Revert "stress2: Use tests as the default test user." 2024-12-04 17:13:05 +01:00
tools git-arc: Properly quote .nm arg 2025-01-15 10:09:43 -07:00
uma/smrstress Remove $FreeBSD$: one-line sh pattern 2023-08-16 11:55:03 -06:00
install.sh Remove $FreeBSD$: one-line sh pattern 2023-08-16 11:55:03 -06:00
make_libdeps.sh Remove $FreeBSD$: one-line sh pattern 2023-08-16 11:55:03 -06:00
README Remove $FreeBSD$: one-line bare tag 2023-08-16 11:55:20 -06:00
tinder.sh Remove $FreeBSD$: one-line sh pattern 2023-08-16 11:55:03 -06:00

This directory tree contains tools used for the maintenance and
testing of FreeBSD.  There is no toplevel Makefile structure since
these tools are not meant to be built as part of the standard system,
though there may be individual Makefiles in some of the subdirs.

Please read the README files in the subdirs for further information.