[GIT PULL] hardening updates for v6.5-rc1

From: Kees Cook
Date: Tue Jun 27 2023 - 20:35:06 EST


Hi Linus,

Please pull these hardening updates for v6.5-rc1. There are 3 areas of
note:

- A bunch of strlcpy()->strscpy() conversions ended up living in my tree
since they were either Acked by maintainers for me to carry, or got
ignored for multiple weeks (and were trivial changes).

- The compiler option -fstrict-flex-arrays=3 has been enabled globally,
and has been in -next for the entire devel cycle. This changes compiler
diagnostics (though mainly just -Warray-bounds which is disabled) and
potential UBSAN_BOUNDS and FORTIFY _warning_ coverage. In other words,
there are no new restrictions, just potentially new warnings. Any new
FORTIFY warnings we've seen have been fixed (usually in their
respective subsystem trees). For more details, see commit
df8fc4e934c12b906d08050d7779f292b9c5c6b5.

- The under-development compiler attribute __counted_by has been added
so that we can start annotating flexible array members with their
associated structure member that tracks the count of flexible array
elements at run-time. It is possible (likely?) that the exact syntax
of the attribute will change before it is finalized, but GCC and Clang
are working together to sort it out. Any changes can be made to the
macro while we continue to add annotations. As an example, I have a
treewide commit waiting with such annotations found via Coccinelle:
https://git.kernel.org/linus/adc5b3cb48a049563dc673f348eab7b6beba8a9b
See commit dd06e72e68bcb4070ef211be100d2896e236c8fb for more details.

These and the other updates and fixes are noted below.

Thanks!

-Kees

The following changes since commit f1fcbaa18b28dec10281551dfe6ed3a3ed80e3d6:

Linux 6.4-rc2 (2023-05-14 12:51:40 -0700)

are available in the Git repository at:

https://git.kernel.org/pub/scm/linux/kernel/git/kees/linux.git tags/hardening-v6.5-rc1

for you to fetch changes up to acf15e07eb06507c69f92394c36052677029b0a8:

netfilter: ipset: Replace strlcpy with strscpy (2023-06-20 13:35:37 -0700)

----------------------------------------------------------------
hardening updates for v6.5-rc1

- Fix KMSAN vs FORTIFY in strlcpy/strlcat (Alexander Potapenko)

- Convert strreplace() to return string start (Andy Shevchenko)

- Flexible array conversions (Arnd Bergmann, Wyes Karny, Kees Cook)

- Add missing function prototypes seen with W=1 (Arnd Bergmann)

- Fix strscpy() kerndoc typo (Arne Welzel)

- Replace strlcpy() with strscpy() across many subsystems which were
either Acked by respective maintainers or were trivial changes that
went ignored for multiple weeks (Azeem Shaikh)

- Remove unneeded cc-option test for UBSAN_TRAP (Nick Desaulniers)

- Add KUnit tests for strcat()-family

- Enable KUnit tests of FORTIFY wrappers under UML

- Add more complete FORTIFY protections for strlcat()

- Add missed disabling of FORTIFY for all arch purgatories.

- Enable -fstrict-flex-arrays=3 globally

- Tightening UBSAN_BOUNDS when using GCC

- Improve checkpatch to check for strcpy, strncpy, and fake flex arrays

- Improve use of const variables in FORTIFY

- Add requested struct_size_t() helper for types not pointers

- Add __counted_by macro for annotating flexible array size members

----------------------------------------------------------------
Alexander Potapenko (1):
string: use __builtin_memcpy() in strlcpy/strlcat

Andy Shevchenko (3):
jbd2: Avoid printing outside the boundary of the buffer
lib/string_helpers: Change returned value of the strreplace()
kobject: Use return value of strreplace()

Arnd Bergmann (2):
autofs: use flexible array in ioctl structure
ubsan: add prototypes for internal functions

Arne Welzel (1):
fortify: strscpy: Fix flipped q and p docstring typo

Azeem Shaikh (27):
dlm: Replace all non-returning strlcpy with strscpy
NFS: Prefer strscpy over strlcpy calls
vboxsf: Replace all non-returning strlcpy with strscpy
scsi: ibmvscsi: Replace all non-returning strlcpy with strscpy
scsi: qedi: Replace all non-returning strlcpy with strscpy
scsi: bnx2i: Replace all non-returning strlcpy with strscpy
scsi: aacraid: Replace all non-returning strlcpy with strscpy
scsi: 3w-9xxx: Replace all non-returning strlcpy with strscpy
tracing: Replace all non-returning strlcpy with strscpy
drm/radeon: Replace all non-returning strlcpy with strscpy
drm/amd/pm: Replace all non-returning strlcpy with strscpy
befs: Replace all non-returning strlcpy with strscpy
ftrace: Replace all non-returning strlcpy with strscpy
drm/display/dp_mst: Replace all non-returning strlcpy with strscpy
drm/rockchip: Replace all non-returning strlcpy with strscpy
drm/mediatek: Replace all non-returning strlcpy with strscpy
drm/sun4i: hdmi: Replace all non-returning strlcpy with strscpy
drm/i2c: tda998x: Replace all non-returning strlcpy with strscpy
staging: most: Replace all non-returning strlcpy with strscpy
clocksource: Replace all non-returning strlcpy with strscpy
Hexagon: Replace all non-returning strlcpy with strscpy
sparc64: Replace all non-returning strlcpy with strscpy
of/flattree: Replace all non-returning strlcpy with strscpy
sh: Replace all non-returning strlcpy with strscpy
kallsyms: Replace all non-returning strlcpy with strscpy
uml: Replace strlcpy with strscpy
netfilter: ipset: Replace strlcpy with strscpy

Kees Cook (18):
ubsan: Tighten UBSAN_BOUNDS on GCC
kunit: tool: Enable CONFIG_FORTIFY_SOURCE under UML
fortify: Allow KUnit test to build without FORTIFY
string: Add Kunit tests for strcat() family
fortify: Use const variables for __member_size tracking
fortify: Add protection for strlcat()
fortify: strcat: Move definition to use fortified strlcat()
kbuild: Enable -fstrict-flex-arrays=3
overflow: Add struct_size_t() helper
md/raid5: Convert stripe_head's "dev" to flexible array member
lkdtm/bugs: Switch from 1-element array to flexible array
Compiler Attributes: Add __counted_by macro
checkpatch: Check for strcpy and strncpy too
x86/purgatory: Do not use fortified string functions
s390/purgatory: Do not use fortified string functions
riscv/purgatory: Do not use fortified string functions
checkpatch: Check for 0-length and 1-element arrays
um: Use HOST_DIR for mrproper

Nick Desaulniers (1):
ubsan: remove cc-option test for UBSAN_TRAP

Wyes Karny (1):
acpi: Replace struct acpi_table_slit 1-element array with flex-array

Documentation/filesystems/autofs-mount-control.rst | 2 +-
Documentation/filesystems/autofs.rst | 2 +-
MAINTAINERS | 1 +
Makefile | 6 +
arch/hexagon/kernel/setup.c | 6 +-
arch/microblaze/kernel/prom.c | 2 +-
arch/riscv/purgatory/Makefile | 2 +-
arch/s390/purgatory/Makefile | 2 +-
arch/sh/drivers/dma/dma-api.c | 2 +-
arch/sh/kernel/setup.c | 4 +-
arch/sparc/kernel/ioport.c | 2 +-
arch/sparc/kernel/setup_32.c | 2 +-
arch/sparc/kernel/setup_64.c | 2 +-
arch/sparc/prom/bootstr_32.c | 2 +-
arch/um/Makefile | 2 +-
arch/um/include/shared/user.h | 1 +
arch/um/os-Linux/drivers/tuntap_user.c | 2 +-
arch/x86/purgatory/Makefile | 2 +-
drivers/gpu/drm/amd/amdgpu/atom.c | 2 +-
drivers/gpu/drm/amd/pm/legacy-dpm/legacy_dpm.c | 2 +-
drivers/gpu/drm/display/drm_dp_helper.c | 2 +-
drivers/gpu/drm/display/drm_dp_mst_topology.c | 2 +-
drivers/gpu/drm/drm_mipi_dsi.c | 2 +-
drivers/gpu/drm/i2c/tda998x_drv.c | 2 +-
drivers/gpu/drm/mediatek/mtk_hdmi_ddc.c | 2 +-
drivers/gpu/drm/radeon/radeon_atombios.c | 4 +-
drivers/gpu/drm/radeon/radeon_combios.c | 4 +-
drivers/gpu/drm/rockchip/inno_hdmi.c | 2 +-
drivers/gpu/drm/rockchip/rk3066_hdmi.c | 2 +-
drivers/gpu/drm/sun4i/sun4i_hdmi_i2c.c | 2 +-
drivers/md/raid5.c | 4 +-
drivers/md/raid5.h | 2 +-
drivers/misc/lkdtm/bugs.c | 4 +-
drivers/most/configfs.c | 8 +-
drivers/net/ethernet/intel/ice/ice_ddp.h | 9 +-
drivers/nvme/host/fc.c | 8 +-
drivers/scsi/3w-9xxx.c | 2 +-
drivers/scsi/aacraid/aachba.c | 2 +-
drivers/scsi/bnx2i/bnx2i_init.c | 2 +-
drivers/scsi/hptiop.c | 4 +-
drivers/scsi/ibmvscsi/ibmvscsi.c | 6 +-
drivers/scsi/megaraid/megaraid_sas_base.c | 12 +-
drivers/scsi/megaraid/megaraid_sas_fp.c | 6 +-
drivers/scsi/qedi/qedi_main.c | 2 +-
drivers/scsi/smartpqi/smartpqi_init.c | 2 +-
fs/befs/btree.c | 2 +-
fs/befs/linuxvfs.c | 2 +-
fs/dlm/config.c | 4 +-
fs/jbd2/journal.c | 6 +-
fs/nfs/nfsroot.c | 2 +-
fs/vboxsf/super.c | 2 +-
fs/xfs/libxfs/xfs_btree.h | 2 +-
fs/xfs/scrub/btree.h | 2 +-
include/acpi/actbl3.h | 2 +-
include/linux/compiler_attributes.h | 13 ++
include/linux/fortify-string.h | 161 ++++++++++++++-------
include/linux/overflow.h | 18 ++-
include/linux/string.h | 2 +-
include/uapi/linux/auto_dev-ioctl.h | 2 +-
kernel/kallsyms.c | 4 +-
kernel/params.c | 2 +-
kernel/time/clocksource.c | 2 +-
kernel/trace/ftrace.c | 18 +--
kernel/trace/trace.c | 8 +-
kernel/trace/trace_events.c | 4 +-
kernel/trace/trace_events_inject.c | 4 +-
kernel/trace/trace_kprobe.c | 2 +-
kernel/trace/trace_probe.c | 2 +-
lib/Kconfig.debug | 7 +-
lib/Kconfig.ubsan | 57 ++++----
lib/Makefile | 1 +
lib/fortify_kunit.c | 14 ++
lib/kobject.c | 3 +-
lib/overflow_kunit.c | 2 +-
lib/strcat_kunit.c | 104 +++++++++++++
lib/string.c | 4 +-
lib/string_helpers.c | 12 +-
lib/ubsan.c | 3 -
lib/ubsan.h | 11 ++
net/netfilter/ipset/ip_set_hash_netiface.c | 10 +-
scripts/Makefile.ubsan | 2 +-
scripts/checkpatch.pl | 24 ++-
tools/testing/kunit/configs/all_tests.config | 2 +
tools/testing/kunit/configs/arch_uml.config | 3 +
84 files changed, 467 insertions(+), 203 deletions(-)
create mode 100644 lib/strcat_kunit.c

--
Kees Cook