Kees Cook 30f20ceb87 overflow: Implement size_t saturating arithmetic helpers ... [ Upstream commit e1be43d9b5 ] In order to perform more open-coded replacements of common allocation size arithmetic, the kernel needs saturating (SIZE_MAX) helpers for multiplication, addition, and subtraction. For example, it is common in allocators, especially on realloc, to add to an existing size: p = krealloc(map->patch, sizeof(struct reg_sequence) * (map->patch_regs + num_regs), GFP_KERNEL); There is no existing saturating replacement for this calculation, and just leaving the addition open coded inside array_size() could potentially overflow as well. For example, an overflow in an expression for a size_t argument might wrap to zero: array_size(anything, something_at_size_max + 1) == 0 Introduce size_mul(), size_add(), and size_sub() helpers that implicitly promote arguments to size_t and saturated calculations for use in allocations. With these helpers it is also possible to redefine array_size(), array3_size(), flex_array_size(), and struct_size() in terms of the new helpers. As with the check_*_overflow() helpers, the new helpers use __must_check, though what is really desired is a way to make sure that assignment is only to a size_t lvalue. Without this, it's still possible to introduce overflow/underflow via type conversion (i.e. from size_t to int). Enforcing this will currently need to be left to static analysis or future use of -Wconversion. Additionally update the overflow unit tests to force runtime evaluation for the pathological cases. Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Gustavo A. R. Silva <gustavoars@kernel.org> Cc: Nathan Chancellor <nathan@kernel.org> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Nick Desaulniers <ndesaulniers@google.com> Cc: Leon Romanovsky <leon@kernel.org> Cc: Keith Busch <kbusch@kernel.org> Cc: Len Baker <len.baker@gmx.com> Signed-off-by: Kees Cook <keescook@chromium.org> Stable-dep-of: e001e60869 ("fs/ntfs3: Harden against integer overflows") Signed-off-by: Sasha Levin <sashal@kernel.org>		2022-12-31 13:14:33 +01:00
..
ABI	mtd: spi-nor: hide jedec_id sysfs attribute if not present	2022-12-31 13:14:11 +01:00
accounting	sched/psi: report zeroes for CPU full at the system level	2022-06-09 10:22:48 +02:00
admin-guide	x86/bugs: Add "unknown" reporting for MMIO Stale Data	2022-08-31 17:16:47 +02:00
arm
arm64	arm64: errata: Remove AES hwcap for COMPAT tasks	2022-10-29 10:12:53 +02:00
block
bpf
cdrom
core-api	Reinstate some of "swiotlb: rework "fix info leak with DMA_FROM_DEVICE""	2022-04-08 14:24:13 +02:00
cpu-freq
crypto
dev-tools	kfence: default to dynamic branch instead of static keys mode	2021-11-12 15:05:49 +01:00
devicetree	dt-bindings: visconti-pcie: Fix interrupts array max constraints	2022-12-31 13:14:24 +01:00
doc-guide
driver-api	spi: Update reference to struct spi_controller	2022-12-31 13:14:08 +01:00
fault-injection	debugfs: fix error when writing negative value to atomic_t debugfs file	2022-12-31 13:14:03 +01:00
fb
features	RISC-V Patches for the 5.15 Merge Window, Part 2	2021-09-11 14:29:42 -07:00
filesystems	fs: record I_DIRTY_TIME even if inode already has I_DIRTY_INODE	2022-10-26 12:34:27 +02:00
firmware-guide	Documentation: ACPI: EINJ: Fix obsolete example	2022-08-25 11:40:01 +02:00
firmware_class
fpga
gpu	drm/i915/display: Move DRRS code its own file	2022-03-08 19:12:40 +01:00
hid
hwmon	hwmon: (lm90) Add basic support for TI TMP461	2021-12-29 12:28:48 +01:00
i2c
ia64
ide
iio
infiniband
input	Input: iforce - add support for Boeder Force Feedback Wheel	2022-09-20 12:39:45 +02:00
isdn
kbuild	Merge branch 'akpm' (patches from Andrew)	2021-09-08 12:55:35 -07:00
kernel-hacking	docs: kernel-hacking: Remove inappropriate text	2021-09-03 15:56:45 -06:00
leds
litmus-tests
livepatch
locking	Documentation/locking/locktypes: Update migrate_disable() bits.	2021-12-14 10:57:18 +01:00
m68k
maintainer
mhi
mips
misc-devices
netlabel
networking	Documentation: fix sctp_wmem in ip-sysctl.rst	2022-08-03 12:03:49 +02:00
nios2
nvdimm
openrisc
parisc
PCI	pci-v5.15-changes	2021-09-07 19:13:42 -07:00
pcmcia
power	Documentation: power: include kernel-doc in Energy Model doc	2021-09-07 21:17:28 +02:00
powerpc
process	overflow: Implement size_t saturating arithmetic helpers	2022-12-31 13:14:33 +01:00
RCU
riscv
s390
scheduler
scsi
security
sh
sound	ALSA: usb-audio: Add quirk bits for enabling/disabling generic implicit fb	2022-06-09 10:22:41 +02:00
sparc
sphinx	docs: sphinx/requirements: Limit jinja2<3.1	2022-04-08 14:22:49 +02:00
sphinx-static
spi
staging
target
timers
trace	tracing/histogram: Update document for KEYS_MAX size	2022-11-10 18:15:38 +01:00
translations	Merge branch 'gcc-min-version-5.1' (make gcc-5.1 the minimum version)	2021-09-13 10:43:04 -07:00
tty/device_drivers	serial: 8250: Add proper clock handling for OxSemi PCIe devices	2022-08-17 14:24:23 +02:00
usb
userspace-api	media: hevc: Embedded indexes in RPS	2022-08-17 14:23:31 +02:00
virt	KVM: s390: pv: don't allow userspace to set the clock under PV	2022-11-16 09:58:17 +01:00
vm	Merge branch 'akpm' (patches from Andrew)	2021-09-08 12:55:35 -07:00
w1
watchdog
x86	Another collection of documentation patches, mostly fixes but also includes	2021-09-08 16:28:14 -07:00
xtensa
.gitignore
arch.rst
asm-annotations.rst
atomic_bitops.txt	locking/atomic: Make test_and_*_bit() ordered on failure	2022-08-25 11:39:54 +02:00
atomic_t.txt
Changes
CodingStyle
conf.py	docs/conf.py: Cope with removal of language=None in Sphinx 5.0.0	2022-06-09 10:23:30 +02:00
COPYING-logo
docutils.conf
dontdiff
index.rst
Kconfig
logo.gif
Makefile
memory-barriers.txt
SubmittingPatches
watch_queue.rst