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Add new CONFIG_UBSAN_BOUNDS test for __counted_by attribute.
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Kees Cook <keescook@chromium.org>
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Numerous production kernel configs (see [1, 2]) are choosing to enable
CONFIG_DEBUG_LIST, which is also being recommended by KSPP for hardened
configs [3]. The motivation behind this is that the option can be used
as a security hardening feature (e.g. CVE-2019-2215 and CVE-2019-2025
are mitigated by the option [4]).
The feature has never been designed with performance in mind, yet common
list manipulation is happening across hot paths all over the kernel.
Introduce CONFIG_LIST_HARDENED, which performs list pointer checking
inline, and only upon list corruption calls the reporting slow path.
To generate optimal machine code with CONFIG_LIST_HARDENED:
1. Elide checking for pointer values which upon dereference would
result in an immediate access fault (i.e. minimal hardening
checks). The trade-off is lower-quality error reports.
2. Use the __preserve_most function attribute (available with Clang,
but not yet with GCC) to minimize the code footprint for calling
the reporting slow path. As a result, function size of callers is
reduced by avoiding saving registers before calling the rarely
called reporting slow path.
Note that all TUs in lib/Makefile already disable function tracing,
including list_debug.c, and __preserve_most's implied notrace has
no effect in this case.
3. Because the inline checks are a subset of the full set of checks in
__list_*_valid_or_report(), always return false if the inline
checks failed. This avoids redundant compare and conditional
branch right after return from the slow path.
As a side-effect of the checks being inline, if the compiler can prove
some condition to always be true, it can completely elide some checks.
Since DEBUG_LIST is functionally a superset of LIST_HARDENED, the
Kconfig variables are changed to reflect that: DEBUG_LIST selects
LIST_HARDENED, whereas LIST_HARDENED itself has no dependency on
DEBUG_LIST.
Running netperf with CONFIG_LIST_HARDENED (using a Clang compiler with
"preserve_most") shows throughput improvements, in my case of ~7% on
average (up to 20-30% on some test cases).
Link: https://r.android.com/1266735 [1]
Link: https://gitlab.archlinux.org/archlinux/packaging/packages/linux/-/blob/main/config [2]
Link: https://kernsec.org/wiki/index.php/Kernel_Self_Protection_Project/Recommended_Settings [3]
Link: https://googleprojectzero.blogspot.com/2019/11/bad-binder-android-in-wild-exploit.html [4]
Signed-off-by: Marco Elver <elver@google.com>
Link: https://lore.kernel.org/r/20230811151847.1594958-3-elver@google.com
Signed-off-by: Kees Cook <keescook@chromium.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc
Pull Char/Misc updates from Greg KH:
"Here is the big set of char/misc and other driver subsystem updates
for 6.5-rc1.
Lots of different, tiny, stuff in here, from a range of smaller driver
subsystems, including pulls from some substems directly:
- IIO driver updates and additions
- W1 driver updates and fixes (and a new maintainer!)
- FPGA driver updates and fixes
- Counter driver updates
- Extcon driver updates
- Interconnect driver updates
- Coresight driver updates
- mfd tree tag merge needed for other updates on top of that, lots of
small driver updates as patches, including:
- static const updates for class structures
- nvmem driver updates
- pcmcia driver fix
- lots of other small driver updates and fixes
All of these have been in linux-next for a while with no reported
problems"
* tag 'char-misc-6.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (243 commits)
bsr: fix build problem with bsr_class static cleanup
comedi: make all 'class' structures const
char: xillybus: make xillybus_class a static const structure
xilinx_hwicap: make icap_class a static const structure
virtio_console: make port class a static const structure
ppdev: make ppdev_class a static const structure
char: misc: make misc_class a static const structure
/dev/mem: make mem_class a static const structure
char: lp: make lp_class a static const structure
dsp56k: make dsp56k_class a static const structure
bsr: make bsr_class a static const structure
oradax: make 'cl' a static const structure
hwtracing: hisi_ptt: Fix potential sleep in atomic context
hwtracing: hisi_ptt: Advertise PERF_PMU_CAP_NO_EXCLUDE for PTT PMU
hwtracing: hisi_ptt: Export available filters through sysfs
hwtracing: hisi_ptt: Add support for dynamically updating the filter list
hwtracing: hisi_ptt: Factor out filter allocation and release operation
samples: pfsm: add CC_CAN_LINK dependency
misc: fastrpc: check return value of devm_kasprintf()
coresight: dummy: Update type of mode parameter in dummy_{sink,source}_enable()
...
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git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux
Pull hardening updates from Kees Cook:
"There are three 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 df8fc4e934c12b.
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 of that last case, I have a treewide commit waiting with
such annotations found via Coccinelle:
https://git.kernel.org/linus/adc5b3cb48a049563dc673f348eab7b6beba8a9b
Also see commit dd06e72e68bcb4 for more details.
Summary:
- 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"
* tag 'hardening-v6.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: (54 commits)
netfilter: ipset: Replace strlcpy with strscpy
uml: Replace strlcpy with strscpy
um: Use HOST_DIR for mrproper
kallsyms: Replace all non-returning strlcpy with strscpy
sh: Replace all non-returning strlcpy with strscpy
of/flattree: Replace all non-returning strlcpy with strscpy
sparc64: Replace all non-returning strlcpy with strscpy
Hexagon: Replace all non-returning strlcpy with strscpy
kobject: Use return value of strreplace()
lib/string_helpers: Change returned value of the strreplace()
jbd2: Avoid printing outside the boundary of the buffer
checkpatch: Check for 0-length and 1-element arrays
riscv/purgatory: Do not use fortified string functions
s390/purgatory: Do not use fortified string functions
x86/purgatory: Do not use fortified string functions
acpi: Replace struct acpi_table_slit 1-element array with flex-array
clocksource: Replace all non-returning strlcpy with strscpy
string: use __builtin_memcpy() in strlcpy/strlcat
staging: most: Replace all non-returning strlcpy with strscpy
drm/i2c: tda998x: Replace all non-returning strlcpy with strscpy
...
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For certain configs objtool will complain like:
vmlinux.o: warning: objtool: lkdtm_UNSET_SMEP+0x1c3: relocation to !ENDBR: native_write_cr4+0x41
What happens is that GCC optimizes the loop:
insn = (unsigned char *)native_write_cr4;
for (i = 0; i < MOV_CR4_DEPTH; i++)
to read something like:
for (insn = (unsigned char *)native_write_cr4;
insn < (unsigned char *)native_write_cr4 + MOV_CR4_DEPTH;
insn++)
Which then obviously generates the text reference
native_write_cr4+041. Since none of this is a fast path, simply
confuse GCC enough to inhibit this optimization.
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/Y3JdgbXRV0MNZ+9h@hirez.programming.kicks-ass.net
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
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Function ll_rw_block was removed in commit 79f597842069 ("fs/buffer:
remove ll_rw_block() helper"). There is no unified function to sumbit
read or write buffer in block layer for now. Consider similar sematics,
we can choose submit_bh() to replace ll_rw_block() as predefined crash
point. In submit_bh(), it also takes read or write flag as the first
argument and invoke submit_bio() to submit I/O request to block layer.
Fixes: 79f597842069 ("fs/buffer: remove ll_rw_block() helper")
Signed-off-by: Yue Zhao <findns94@gmail.com>
Acked-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20230503162944.3969-1-findns94@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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The testing for ARRAY_BOUNDS just wants an uninstrumented array,
and the proper flexible array definition is fine for that.
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Bill Wendling <morbo@google.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
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Fixes the following warning:
vmlinux.o: warning: objtool: check_stackleak_irqoff+0x2b6: call to _printk() leaves .noinstr.text section
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/ee5209f53aa0a62aea58be18f2b78b17606779a6.1681320026.git.jpoimboe@kernel.org
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Since the commits starting with c37495d6254c ("slab: add __alloc_size
attributes for better bounds checking"), the compilers have runtime
allocation size hints available in some places. This was immediately
available to CONFIG_UBSAN_BOUNDS, but CONFIG_FORTIFY_SOURCE needed
updating to explicitly make use of the hints via the associated
__builtin_dynamic_object_size() helper. Detect and use the builtin when
it is available, increasing the accuracy of the mitigation. When runtime
sizes are not available, __builtin_dynamic_object_size() falls back to
__builtin_object_size(), leaving the existing bounds checking unchanged.
Additionally update the VMALLOC_LINEAR_OVERFLOW LKDTM test to make the
hint invisible, otherwise the architectural defense is not exercised
(the buffer overflow is detected in the memset() rather than when it
crosses the edge of the allocation).
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Tom Rix <trix@redhat.com>
Cc: linux-hardening@vger.kernel.org
Cc: llvm@lists.linux.dev
Reviewed-by: Miguel Ojeda <ojeda@kernel.org> # include/linux/compiler_attributes.h
Signed-off-by: Kees Cook <keescook@chromium.org>
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The CFI test uses the branch-protection=none compiler attribute to
disable PAC return address protection on a function. While newer GCC
versions support this attribute, older versions (GCC 7 and 8) instead
supported the sign-return-address=none attribute, leading to a build
failure when the test is built with older compilers. Fix it by checking
which attribute is supported and using the correct one.
Fixes: 2e53b877dc12 ("lkdtm: Add CFI_BACKWARD to test ROP mitigations")
Reported-by: Daniel Díaz <daniel.diaz@linaro.org>
Signed-off-by: Kristina Martsenko <kristina.martsenko@arm.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/all/CAEUSe78kDPxQmQqCWW-_9LCgJDFhAeMoVBFnX9QLx18Z4uT4VQ@mail.gmail.com/
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git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux
Pull kernel hardening updates from Kees Cook:
"Most of the collected changes here are fixes across the tree for
various hardening features (details noted below).
The most notable new feature here is the addition of the memcpy()
overflow warning (under CONFIG_FORTIFY_SOURCE), which is the next step
on the path to killing the common class of "trivially detectable"
buffer overflow conditions (i.e. on arrays with sizes known at compile
time) that have resulted in many exploitable vulnerabilities over the
years (e.g. BleedingTooth).
This feature is expected to still have some undiscovered false
positives. It's been in -next for a full development cycle and all the
reported false positives have been fixed in their respective trees.
All the known-bad code patterns we could find with Coccinelle are also
either fixed in their respective trees or in flight.
The commit message in commit 54d9469bc515 ("fortify: Add run-time WARN
for cross-field memcpy()") for the feature has extensive details, but
I'll repeat here that this is a warning _only_, and is not intended to
actually block overflows (yet). The many patches fixing array sizes
and struct members have been landing for several years now, and we're
finally able to turn this on to find any remaining stragglers.
Summary:
Various fixes across several hardening areas:
- loadpin: Fix verity target enforcement (Matthias Kaehlcke).
- zero-call-used-regs: Add missing clobbers in paravirt (Bill
Wendling).
- CFI: clean up sparc function pointer type mismatches (Bart Van
Assche).
- Clang: Adjust compiler flag detection for various Clang changes
(Sami Tolvanen, Kees Cook).
- fortify: Fix warnings in arch-specific code in sh, ARM, and xen.
Improvements to existing features:
- testing: improve overflow KUnit test, introduce fortify KUnit test,
add more coverage to LKDTM tests (Bart Van Assche, Kees Cook).
- overflow: Relax overflow type checking for wider utility.
New features:
- string: Introduce strtomem() and strtomem_pad() to fill a gap in
strncpy() replacement needs.
- um: Enable FORTIFY_SOURCE support.
- fortify: Enable run-time struct member memcpy() overflow warning"
* tag 'hardening-v6.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: (27 commits)
Makefile.extrawarn: Move -Wcast-function-type-strict to W=1
hardening: Remove Clang's enable flag for -ftrivial-auto-var-init=zero
sparc: Unbreak the build
x86/paravirt: add extra clobbers with ZERO_CALL_USED_REGS enabled
x86/paravirt: clean up typos and grammaros
fortify: Convert to struct vs member helpers
fortify: Explicitly check bounds are compile-time constants
x86/entry: Work around Clang __bdos() bug
ARM: decompressor: Include .data.rel.ro.local
fortify: Adjust KUnit test for modular build
sh: machvec: Use char[] for section boundaries
kunit/memcpy: Avoid pathological compile-time string size
lib: Improve the is_signed_type() kunit test
LoadPin: Require file with verity root digests to have a header
dm: verity-loadpin: Only trust verity targets with enforcement
LoadPin: Fix Kconfig doc about format of file with verity digests
um: Enable FORTIFY_SOURCE
lkdtm: Update tests for memcpy() run-time warnings
fortify: Add run-time WARN for cross-field memcpy()
fortify: Use SIZE_MAX instead of (size_t)-1
...
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With -fsanitize=kcfi, we no longer need function_nocfi() as
the compiler won't change function references to point to a
jump table. Remove all implementations and uses of the macro.
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Tested-by: Kees Cook <keescook@chromium.org>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20220908215504.3686827-14-samitolvanen@google.com
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Clang can convert the indirect calls in lkdtm_CFI_FORWARD_PROTO into
direct calls. Move the call into a noinline function that accepts the
target address as an argument to ensure the compiler actually emits an
indirect call instead.
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Kees Cook <keescook@chromium.org>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20220908215504.3686827-8-samitolvanen@google.com
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Clarify the LKDTM FORTIFY tests, and add tests for the mem*() family of
functions, now that run-time checking is distinct.
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: linux-kselftest@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc
Pull char / misc driver updates from Greg KH:
"Here is the large set of char and misc and other driver subsystem
changes for 6.0-rc1.
Highlights include:
- large set of IIO driver updates, additions, and cleanups
- new habanalabs device support added (loads of register maps much
like GPUs have)
- soundwire driver updates
- phy driver updates
- slimbus driver updates
- tiny virt driver fixes and updates
- misc driver fixes and updates
- interconnect driver updates
- hwtracing driver updates
- fpga driver updates
- extcon driver updates
- firmware driver updates
- counter driver update
- mhi driver fixes and updates
- binder driver fixes and updates
- speakup driver fixes
All of these have been in linux-next for a while without any reported
problems"
* tag 'char-misc-6.0-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (634 commits)
drivers: lkdtm: fix clang -Wformat warning
char: remove VR41XX related char driver
misc: Mark MICROCODE_MINOR unused
spmi: trace: fix stack-out-of-bound access in SPMI tracing functions
dt-bindings: iio: adc: Add compatible for MT8188
iio: light: isl29028: Fix the warning in isl29028_remove()
iio: accel: sca3300: Extend the trigger buffer from 16 to 32 bytes
iio: fix iio_format_avail_range() printing for none IIO_VAL_INT
iio: adc: max1027: unlock on error path in max1027_read_single_value()
iio: proximity: sx9324: add empty line in front of bullet list
iio: magnetometer: hmc5843: Remove duplicate 'the'
iio: magn: yas530: Use DEFINE_RUNTIME_DEV_PM_OPS() and pm_ptr() macros
iio: magnetometer: ak8974: Use DEFINE_RUNTIME_DEV_PM_OPS() and pm_ptr() macros
iio: light: veml6030: Use DEFINE_RUNTIME_DEV_PM_OPS() and pm_ptr() macros
iio: light: vcnl4035: Use DEFINE_RUNTIME_DEV_PM_OPS() and pm_ptr() macros
iio: light: vcnl4000: Use DEFINE_RUNTIME_DEV_PM_OPS() and pm_ptr() macros
iio: light: tsl2591: Use DEFINE_RUNTIME_DEV_PM_OPS() and pm_ptr()
iio: light: tsl2583: Use DEFINE_RUNTIME_DEV_PM_OPS and pm_ptr()
iio: light: isl29028: Use DEFINE_RUNTIME_DEV_PM_OPS() and pm_ptr()
iio: light: gp2ap002: Switch to DEFINE_RUNTIME_DEV_PM_OPS and pm_ptr()
...
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git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux
Pull hardening updates from Kees Cook:
- Fix Sparse warnings with randomizd kstack (GONG, Ruiqi)
- Replace uintptr_t with unsigned long in usercopy (Jason A. Donenfeld)
- Fix Clang -Wforward warning in LKDTM (Justin Stitt)
- Fix comment to correctly refer to STRICT_DEVMEM (Lukas Bulwahn)
- Introduce dm-verity binding logic to LoadPin LSM (Matthias Kaehlcke)
- Clean up warnings and overflow and KASAN tests (Kees Cook)
* tag 'hardening-v5.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
dm: verity-loadpin: Drop use of dm_table_get_num_targets()
kasan: test: Silence GCC 12 warnings
drivers: lkdtm: fix clang -Wformat warning
x86: mm: refer to the intended config STRICT_DEVMEM in a comment
dm: verity-loadpin: Use CONFIG_SECURITY_LOADPIN_VERITY for conditional compilation
LoadPin: Enable loading from trusted dm-verity devices
dm: Add verity helpers for LoadPin
stack: Declare {randomize_,}kstack_offset to fix Sparse warnings
lib: overflow: Do not define 64-bit tests on 32-bit
MAINTAINERS: Add a general "kernel hardening" section
usercopy: use unsigned long instead of uintptr_t
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When building with Clang we encounter the following warning
(ARCH=hexagon + CONFIG_FRAME_WARN=0):
| ../drivers/misc/lkdtm/bugs.c:107:3: error: format specifies type
| 'unsigned long' but the argument has type 'int' [-Werror,-Wformat]
| REC_STACK_SIZE, recur_count);
| ^~~~~~~~~~~~~~
Cast REC_STACK_SIZE to `unsigned long` to match format specifier `%lu`
as well as maintain symmetry with `#define REC_STACK_SIZE
(_AC(CONFIG_FRAME_WARN, UL) / 2)`.
Link: https://github.com/ClangBuiltLinux/linux/issues/378
Fixes: 24cccab42c419 ("lkdtm/bugs: Adjust recursion test to avoid elision")
Reported-by: Nathan Chancellor <nathan@kernel.org>
Suggested-by: Nathan Chancellor <nathan@kernel.org>
Suggested-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Justin Stitt <justinstitt@google.com>
Link: https://lore.kernel.org/r/20220721215706.4153027-1-justinstitt@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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When building with Clang we encounter the following warning
(ARCH=hexagon + CONFIG_FRAME_WARN=0):
| ../drivers/misc/lkdtm/bugs.c:107:3: error: format specifies type
| 'unsigned long' but the argument has type 'int' [-Werror,-Wformat]
| REC_STACK_SIZE, recur_count);
| ^~~~~~~~~~~~~~
Cast REC_STACK_SIZE to `unsigned long` to match format specifier `%lu`
as well as maintain symmetry with `#define REC_STACK_SIZE
(_AC(CONFIG_FRAME_WARN, UL) / 2)`.
Link: https://github.com/ClangBuiltLinux/linux/issues/378
Reported-by: Nathan Chancellor <nathan@kernel.org>
Suggested-by: Nathan Chancellor <nathan@kernel.org>
Suggested-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Justin Stitt <justinstitt@google.com>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Acked-by: Kees Cook <keescook@chromium.org>
Fixes: 24cccab42c419 ("lkdtm/bugs: Adjust recursion test to avoid elision")
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20220721215706.4153027-1-justinstitt@google.com
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The following warning was seen:
WARNING: CPU: 0 PID: 0 at arch/x86/kernel/alternative.c:557 apply_returns (arch/x86/kernel/alternative.c:557 (discriminator 1))
Modules linked in:
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.19.0-rc4-00008-gee88d363d156 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.0-debian-1.16.0-4 04/01/2014
RIP: 0010:apply_returns (arch/x86/kernel/alternative.c:557 (discriminator 1))
Code: ff ff 74 cb 48 83 c5 04 49 39 ee 0f 87 81 fe ff ff e9 22 ff ff ff 0f 0b 48 83 c5 04 49 39 ee 0f 87 6d fe ff ff e9 0e ff ff ff <0f> 0b 48 83 c5 04 49 39 ee 0f 87 59 fe ff ff e9 fa fe ff ff 48 89
The warning happened when apply_returns() failed to convert "JMP
__x86_return_thunk" to RET. It was instead a JMP to nowhere, due to the
thunk relocation not getting resolved.
That rodata.o code is objcopy'd to .rodata, and later memcpy'd, so
relocations don't work (and are apparently silently ignored).
LKDTM is only used for testing, so the naked RET should be fine. So
just disable return thunks for that file.
While at it, disable objtool and KCSAN for the file.
Fixes: 0b53c374b9ef ("x86/retpoline: Use -mfunction-return")
Reported-by: kernel test robot <oliver.sang@intel.com>
Debugged-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/lkml/Ys58BxHxoDZ7rfpr@xsang-OptiPlex-9020/
|
|
There is a pointer being initialized with a zero, use NULL instead.
Cleans up sparse warning:
drivers/misc/lkdtm/cfi.c:100:27: warning: Using plain integer as NULL pointer
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Link: https://lore.kernel.org/r/20220612202708.2754270-1-colin.i.king@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc
Pull char / misc / other smaller driver subsystem updates from Greg KH:
"Here is the large set of char, misc, and other driver subsystem
updates for 5.19-rc1. The merge request for this has been delayed as I
wanted to get lots of linux-next testing due to some late arrivals of
changes for the habannalabs driver.
Highlights of this merge are:
- habanalabs driver updates for new hardware types and fixes and
other updates
- IIO driver tree merge which includes loads of new IIO drivers and
cleanups and additions
- PHY driver tree merge with new drivers and small updates to
existing ones
- interconnect driver tree merge with fixes and updates
- soundwire driver tree merge with some small fixes
- coresight driver tree merge with small fixes and updates
- mhi bus driver tree merge with lots of updates and new device
support
- firmware driver updates
- fpga driver updates
- lkdtm driver updates (with a merge conflict, more on that below)
- extcon driver tree merge with small updates
- lots of other tiny driver updates and fixes and cleanups, full
details in the shortlog.
All of these have been in linux-next for almost 2 weeks with no
reported problems"
* tag 'char-misc-5.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (387 commits)
habanalabs: use separate structure info for each error collect data
habanalabs: fix missing handle shift during mmap
habanalabs: remove hdev from hl_ctx_get args
habanalabs: do MMU prefetch as deferred work
habanalabs: order memory manager messages
habanalabs: return -EFAULT on copy_to_user error
habanalabs: use NULL for eventfd
habanalabs: update firmware header
habanalabs: add support for notification via eventfd
habanalabs: add topic to memory manager buffer
habanalabs: handle race in driver fini
habanalabs: add device memory scrub ability through debugfs
habanalabs: use unified memory manager for CB flow
habanalabs: unified memory manager new code for CB flow
habanalabs/gaudi: set arbitration timeout to a high value
habanalabs: add put by handle method to memory manager
habanalabs: hide memory manager page shift
habanalabs: Add separate poll interval value for protocol
habanalabs: use get_task_pid() to take PID
habanalabs: add prefetch flag to the MAP operation
...
|
|
With the kmalloc() size annotations, GCC is smart enough to realize that
LKDTM is intentionally writing past the end of the buffer. This is on
purpose, of course, so hide the buffer from the optimizer. Silences:
../drivers/misc/lkdtm/heap.c: In function 'lkdtm_SLAB_LINEAR_OVERFLOW':
../drivers/misc/lkdtm/heap.c:59:13: warning: array subscript 256 is outside array bounds of 'void[1020]' [-Warray-bounds]
59 | data[1024 / sizeof(u32)] = 0x12345678;
| ~~~~^~~~~~~~~~~~~~~~~~~~
In file included from ../drivers/misc/lkdtm/heap.c:7:
In function 'kmalloc',
inlined from 'lkdtm_SLAB_LINEAR_OVERFLOW' at ../drivers/misc/lkdtm/heap.c:54:14:
../include/linux/slab.h:581:24: note: at offset 1024 into object of size 1020 allocated by 'kmem_cache_alloc_trace'
581 | return kmem_cache_alloc_trace(
| ^~~~~~~~~~~~~~~~~~~~~~~
582 | kmalloc_caches[kmalloc_type(flags)][index],
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
583 | flags, size);
| ~~~~~~~~~~~~
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Kees Cook <keescook@chromium.org>
|
|
Add coverage for the recently added usercopy checks for vmalloc and
folios, via USERCOPY_VMALLOC and USERCOPY_FOLIO respectively.
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Kees Cook <keescook@chromium.org>
|
|
To more clearly distinguish between the various heap types, rename the
slab tests to "slab".
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: linux-kselftest@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
|
|
Recent rework broke building LKDTM when CONFIG_GCC_PLUGIN_STACKLEAK=n.
This patch fixes that breakage.
Prior to recent stackleak rework, the LKDTM STACKLEAK_ERASING code could
be built when the kernel was not built with stackleak support, and would
run a test that would almost certainly fail (or pass by sheer cosmic
coincidence), e.g.
| # echo STACKLEAK_ERASING > /sys/kernel/debug/provoke-crash/DIRECT
| lkdtm: Performing direct entry STACKLEAK_ERASING
| lkdtm: checking unused part of the thread stack (15560 bytes)...
| lkdtm: FAIL: the erased part is not found (checked 15560 bytes)
| lkdtm: FAIL: the thread stack is NOT properly erased!
| lkdtm: This is probably expected, since this kernel (5.18.0-rc2 aarch64) was built *without* CONFIG_GCC_PLUGIN_STACKLEAK=y
The recent rework to the test made it more accurate by using helpers
which are only defined when CONFIG_GCC_PLUGIN_STACKLEAK=y, and so when
building LKDTM when CONFIG_GCC_PLUGIN_STACKLEAK=n, we get a build
failure:
| drivers/misc/lkdtm/stackleak.c: In function 'check_stackleak_irqoff':
| drivers/misc/lkdtm/stackleak.c:30:46: error: implicit declaration of function 'stackleak_task_low_bound' [-Werror=implicit-function-declaration]
| 30 | const unsigned long task_stack_low = stackleak_task_low_bound(current);
| | ^~~~~~~~~~~~~~~~~~~~~~~~
| drivers/misc/lkdtm/stackleak.c:31:47: error: implicit declaration of function 'stackleak_task_high_bound'; did you mean 'stackleak_task_init'? [-Werror=implicit-function-declaration]
| 31 | const unsigned long task_stack_high = stackleak_task_high_bound(current);
| | ^~~~~~~~~~~~~~~~~~~~~~~~~
| | stackleak_task_init
| drivers/misc/lkdtm/stackleak.c:33:48: error: 'struct task_struct' has no member named 'lowest_stack'
| 33 | const unsigned long lowest_sp = current->lowest_stack;
| | ^~
| drivers/misc/lkdtm/stackleak.c:74:23: error: implicit declaration of function 'stackleak_find_top_of_poison' [-Werror=implicit-function-declaration]
| 74 | poison_high = stackleak_find_top_of_poison(task_stack_low, untracked_high);
| | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
This patch fixes the issue by not compiling the body of the test when
CONFIG_GCC_PLUGIN_STACKLEAK=n, and replacing this with an unconditional
XFAIL message. This means the pr_expected_config() in
check_stackleak_irqoff() is redundant, and so it is removed.
Where an architecture does not support stackleak, the test will log:
| # echo STACKLEAK_ERASING > /sys/kernel/debug/provoke-crash/DIRECT
| lkdtm: Performing direct entry STACKLEAK_ERASING
| lkdtm: XFAIL: stackleak is not supported on this arch (HAVE_ARCH_STACKLEAK=n)
Where an architectures does support stackleak, but this has not been
compiled in, the test will log:
| # echo STACKLEAK_ERASING > /sys/kernel/debug/provoke-crash/DIRECT
| lkdtm: Performing direct entry STACKLEAK_ERASING
| lkdtm: XFAIL: stackleak is not enabled (CONFIG_GCC_PLUGIN_STACKLEAK=n)
Where stackleak has been compiled in, the test behaves as usual:
| # echo STACKLEAK_ERASING > /sys/kernel/debug/provoke-crash/DIRECT
| lkdtm: Performing direct entry STACKLEAK_ERASING
| lkdtm: stackleak stack usage:
| high offset: 336 bytes
| current: 688 bytes
| lowest: 1232 bytes
| tracked: 1232 bytes
| untracked: 672 bytes
| poisoned: 14136 bytes
| low offset: 8 bytes
| lkdtm: OK: the rest of the thread stack is properly erased
Fixes: f4cfacd92972cc44 ("lkdtm/stackleak: rework boundary management")
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Alexander Popov <alex.popov@linux.com>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20220506121145.1162908-1-mark.rutland@arm.com
|
|
The stackleak code relies upon the current SP and lowest recorded SP
falling within expected task stack boundaries.
Check this at the start of the test.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Alexander Popov <alex.popov@linux.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20220427173128.2603085-12-mark.rutland@arm.com
|
|
The lkdtm_STACKLEAK_ERASING() test is instrumentable and runs with IRQs
unmasked, so it's possible for unrelated code to clobber the task stack
and/or manipulate current->lowest_stack while the test is running,
resulting in spurious failures.
The regular stackleak erasing code is non-instrumentable and runs with
IRQs masked, preventing similar issues.
Make the body of the test non-instrumentable, and run it with IRQs
masked, avoiding such spurious failures.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Alexander Popov <alex.popov@linux.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20220427173128.2603085-11-mark.rutland@arm.com
|
|
There are a few problems with the way the LKDTM STACKLEAK_ERASING test
manipulates the stack pointer and boundary values:
* It uses the address of a local variable to determine the current stack
pointer, rather than using current_stack_pointer directly. As the
local variable could be placed anywhere within the stack frame, this
can be an over-estimate of the true stack pointer value.
* Is uses an estimate of the current stack pointer as the upper boundary
when scanning for poison, even though prior functions could have used
more stack (and may have updated current->lowest stack accordingly).
* A pr_info() call is made in the middle of the test. As the printk()
code is out-of-line and will make use of the stack, this could clobber
poison and/or adjust current->lowest_stack. It would be better to log
the metadata after the body of the test to avoid such problems.
These have been observed to result in spurious test failures on arm64.
In addition to this there are a couple of things which are sub-optimal:
* To avoid the STACK_END_MAGIC value, it conditionally modifies 'left'
if this contains more than a single element, when it could instead
calculate the bound unconditionally using stackleak_task_low_bound().
* It open-codes the poison scanning. It would be better if this used the
same helper code as used by erasing function so that the two cannot
diverge.
This patch reworks the test to avoid these issues, making use of the
recently introduced helpers to ensure this is aligned with the regular
stackleak code.
As the new code tests stack boundaries before accessing the stack, there
is no need to fail early when the tracked or untracked portions of the
stack extend all the way to the low stack boundary.
As stackleak_find_top_of_poison() is now used to find the top of the
poisoned region of the stack, the subsequent poison checking starts at
this boundary and verifies that stackleak_find_top_of_poison() is
working correctly.
The pr_info() which logged the untracked portion of stack is now moved
to the end of the function, and logs the size of all the portions of the
stack relevant to the test, including the portions at the top and bottom
of the stack which are not erased or scanned, and the current / lowest
recorded stack usage.
Tested on x86_64:
| # echo STACKLEAK_ERASING > /sys/kernel/debug/provoke-crash/DIRECT
| lkdtm: Performing direct entry STACKLEAK_ERASING
| lkdtm: stackleak stack usage:
| high offset: 168 bytes
| current: 336 bytes
| lowest: 656 bytes
| tracked: 656 bytes
| untracked: 400 bytes
| poisoned: 15152 bytes
| low offset: 8 bytes
| lkdtm: OK: the rest of the thread stack is properly erased
Tested on arm64:
| # echo STACKLEAK_ERASING > /sys/kernel/debug/provoke-crash/DIRECT
| lkdtm: Performing direct entry STACKLEAK_ERASING
| lkdtm: stackleak stack usage:
| high offset: 336 bytes
| current: 656 bytes
| lowest: 1232 bytes
| tracked: 1232 bytes
| untracked: 672 bytes
| poisoned: 14136 bytes
| low offset: 8 bytes
| lkdtm: OK: the rest of the thread stack is properly erased
Tested on arm64 with deliberate breakage to the starting stack value and
poison scanning:
| # echo STACKLEAK_ERASING > /sys/kernel/debug/provoke-crash/DIRECT
| lkdtm: Performing direct entry STACKLEAK_ERASING
| lkdtm: FAIL: non-poison value 24 bytes below poison boundary: 0x0
| lkdtm: FAIL: non-poison value 32 bytes below poison boundary: 0xffff8000083dbc00
...
| lkdtm: FAIL: non-poison value 1912 bytes below poison boundary: 0x78b4b9999e8cb15
| lkdtm: FAIL: non-poison value 1920 bytes below poison boundary: 0xffff8000083db400
| lkdtm: stackleak stack usage:
| high offset: 336 bytes
| current: 688 bytes
| lowest: 1232 bytes
| tracked: 576 bytes
| untracked: 288 bytes
| poisoned: 15176 bytes
| low offset: 8 bytes
| lkdtm: FAIL: the thread stack is NOT properly erased!
| lkdtm: Unexpected! This kernel (5.18.0-rc1-00013-g1f7b1f1e29e0-dirty aarch64) was built with CONFIG_GCC_PLUGIN_STACKLEAK=y
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Alexander Popov <alex.popov@linux.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20220427173128.2603085-10-mark.rutland@arm.com
|
|
The lkdtm_STACKLEAK_ERASING() test scans for a contiguous block of
poison values between the low stack bound and the stack pointer, and
fails if it does not find a sufficiently large block.
This can happen legitimately if the scan the low stack bound, which
could occur if functions called prior to lkdtm_STACKLEAK_ERASING() used
a large amount of stack. If this were to occur, it means that the erased
portion of the stack is smaller than the size used by the scan, but does
not cause a functional problem
In practice this is unlikely to happen, but as this is legitimate and
would not result in a functional problem, the test should not fail in
this case.
Remove the spurious failure case.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Alexander Popov <alex.popov@linux.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20220427173128.2603085-9-mark.rutland@arm.com
|
|
The masking for PAC bits wasn't handling 32-bit architectures correctly.
Replace the u64 cast with uintptr_t.
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Link: https://lore.kernel.org/lkml/CAMuHMdVz-J-1ZQ08u0bsQihDkcRmEPrtX5B_oRJ+Ns5jrasnUw@mail.gmail.com
Fixes: 2e53b877dc12 ("lkdtm: Add CFI_BACKWARD to test ROP mitigations")
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Kees Cook <keescook@chromium.org>
|
|
In order to test various backward-edge control flow integrity methods,
add a test that manipulates the return address on the stack. Currently
only arm64 Pointer Authentication and Shadow Call Stack is supported.
$ echo CFI_BACKWARD | cat >/sys/kernel/debug/provoke-crash/DIRECT
Under SCS, successful test of the mitigation is reported as:
lkdtm: Performing direct entry CFI_BACKWARD
lkdtm: Attempting unchecked stack return address redirection ...
lkdtm: ok: redirected stack return address.
lkdtm: Attempting checked stack return address redirection ...
lkdtm: ok: control flow unchanged.
Under PAC, successful test of the mitigation is reported by the PAC
exception handler:
lkdtm: Performing direct entry CFI_BACKWARD
lkdtm: Attempting unchecked stack return address redirection ...
lkdtm: ok: redirected stack return address.
lkdtm: Attempting checked stack return address redirection ...
Unable to handle kernel paging request at virtual address bfffffc0088d0514
Mem abort info:
ESR = 0x86000004
EC = 0x21: IABT (current EL), IL = 32 bits
SET = 0, FnV = 0
EA = 0, S1PTW = 0
FSC = 0x04: level 0 translation fault
[bfffffc0088d0514] address between user and kernel address ranges
...
If the CONFIGs are missing (or the mitigation isn't working), failure
is reported as:
lkdtm: Performing direct entry CFI_BACKWARD
lkdtm: Attempting unchecked stack return address redirection ...
lkdtm: ok: redirected stack return address.
lkdtm: Attempting checked stack return address redirection ...
lkdtm: FAIL: stack return address was redirected!
lkdtm: This is probably expected, since this kernel was built *without* CONFIG_ARM64_PTR_AUTH_KERNEL=y nor CONFIG_SHADOW_CALL_STACK=y
Co-developed-by: Dan Li <ashimida@linux.alibaba.com>
Signed-off-by: Dan Li <ashimida@linux.alibaba.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/lkml/20220416001103.1524653-1-keescook@chromium.org
|
|
It's long been annoying that to add a new LKDTM test one had to update
lkdtm.h and core.c to get it "registered". Switch to a per-category
list and update the crashtype walking code in core.c to handle it.
This also means that all the lkdtm_* tests themselves can be static now.
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
|
|
When you don't select CONFIG_UBSAN_TRAP, you get:
# echo ARRAY_BOUNDS > /sys/kernel/debug/provoke-crash/DIRECT
[ 102.265827] ================================================================================
[ 102.278433] UBSAN: array-index-out-of-bounds in drivers/misc/lkdtm/bugs.c:342:16
[ 102.287207] index 8 is out of range for type 'char [8]'
[ 102.298722] ================================================================================
[ 102.313712] lkdtm: FAIL: survived array bounds overflow!
[ 102.318770] lkdtm: Unexpected! This kernel (5.16.0-rc1-s3k-dev-01884-g720dcf79314a ppc) was built with CONFIG_UBSAN_BOUNDS=y
It is not correct because when CONFIG_UBSAN_TRAP is not selected
you can't expect array bounds overflow to kill the thread.
Modify the logic so that when the kernel is built with
CONFIG_UBSAN_BOUNDS but without CONFIG_UBSAN_TRAP, you get a warning
about CONFIG_UBSAN_TRAP not been selected instead.
This also require a fix of pr_expected_config(), otherwise the
following error is encountered.
CC drivers/misc/lkdtm/bugs.o
drivers/misc/lkdtm/bugs.c: In function 'lkdtm_ARRAY_BOUNDS':
drivers/misc/lkdtm/bugs.c:351:2: error: 'else' without a previous 'if'
351 | else
| ^~~~
Fixes: c75be56e35b2 ("lkdtm/bugs: Add ARRAY_BOUNDS to selftests")
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/363b58690e907c677252467a94fe49444c80ea76.1649704381.git.christophe.leroy@csgroup.eu
|
|
To be sufficiently out of range for the usercopy test to see the lifetime
mismatch, expand the size of the "bad" buffer, which will let it be
beyond current_stack_pointer regardless of stack growth direction.
Paired with the recent addition of stack depth checking under
CONFIG_HARDENED_USERCOPY=y, this will correctly start tripping again.
Reported-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
Link: https://lore.kernel.org/lkml/762faf1b-0443-5ddf-4430-44a20cf2ec4d@collabora.com/
Signed-off-by: Kees Cook <keescook@chromium.org>
|
|
It wasn't clear when SLAB_LINEAR_OVERFLOW would be expected to trip.
Explicitly describe it and include the CONFIGs in the kselftest.
Cc: Muhammad Usama Anjum <usama.anjum@collabora.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: linux-kselftest@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
|
|
As the possible failure of the kmalloc(), the not_checked and checked
could be NULL pointer.
Therefore, it should be better to check it in order to avoid the
dereference of the NULL pointer.
Also, we need to kfree the 'not_checked' and 'checked' to avoid
the memory leak if fails.
And since it is just a test, it may directly return without error
number.
Fixes: ae2e1aad3e48 ("drivers/misc/lkdtm/bugs.c: add arithmetic overflow and array bounds checks")
Signed-off-by: Jiasheng Jiang <jiasheng@iscas.ac.cn>
Acked-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20220120092936.1874264-1-jiasheng@iscas.ac.cn
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc
Pull char/misc and other driver updates from Greg KH:
"Here is the big set of char/misc and other small driver subsystem
updates for 5.18-rc1.
Included in here are merges from driver subsystems which contain:
- iio driver updates and new drivers
- fsi driver updates
- fpga driver updates
- habanalabs driver updates and support for new hardware
- soundwire driver updates and new drivers
- phy driver updates and new drivers
- coresight driver updates
- icc driver updates
Individual changes include:
- mei driver updates
- interconnect driver updates
- new PECI driver subsystem added
- vmci driver updates
- lots of tiny misc/char driver updates
All of these have been in linux-next for a while with no reported
problems"
* tag 'char-misc-5.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (556 commits)
firmware: google: Properly state IOMEM dependency
kgdbts: fix return value of __setup handler
firmware: sysfb: fix platform-device leak in error path
firmware: stratix10-svc: add missing callback parameter on RSU
arm64: dts: qcom: add non-secure domain property to fastrpc nodes
misc: fastrpc: Add dma handle implementation
misc: fastrpc: Add fdlist implementation
misc: fastrpc: Add helper function to get list and page
misc: fastrpc: Add support to secure memory map
dt-bindings: misc: add fastrpc domain vmid property
misc: fastrpc: check before loading process to the DSP
misc: fastrpc: add secure domain support
dt-bindings: misc: add property to support non-secure DSP
misc: fastrpc: Add support to get DSP capabilities
misc: fastrpc: add support for FASTRPC_IOCTL_MEM_MAP/UNMAP
misc: fastrpc: separate fastrpc device from channel context
dt-bindings: nvmem: brcm,nvram: add basic NVMEM cells
dt-bindings: nvmem: make "reg" property optional
nvmem: brcm_nvram: parse NVRAM content into NVMEM cells
nvmem: dt-bindings: Fix the error of dt-bindings check
...
|
|
The memcpy() runtime defenses are still not landed, so test with
strncpy() for now.
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reported-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
Reviewed-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20220216202548.2093883-1-keescook@chromium.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Add WRITE_OPD to check that you can't modify function
descriptors.
Gives the following result when function descriptors are
not protected:
lkdtm: Performing direct entry WRITE_OPD
lkdtm: attempting bad 16 bytes write at c00000000269b358
lkdtm: FAIL: survived bad write
lkdtm: do_nothing was hijacked!
Looks like a standard compiler barrier() is not enough to force
GCC to use the modified function descriptor. Had to add a fake empty
inline assembly to force GCC to reload the function descriptor.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/7eeba50d16a35e9d799820e43304150225f20197.1644928018.git.christophe.leroy@csgroup.eu
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execute_location() and execute_user_location() intent
to copy do_nothing() text and execute it at a new location.
However, at the time being it doesn't copy do_nothing() function
but do_nothing() function descriptor which still points to the
original text. So at the end it still executes do_nothing() at
its original location allthough using a copied function descriptor.
So, fix that by really copying do_nothing() text and build a new
function descriptor by copying do_nothing() function descriptor and
updating the target address with the new location.
Also fix the displayed addresses by dereferencing do_nothing()
function descriptor.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/4055839683d8d643cd99be121f4767c7c611b970.1644928018.git.christophe.leroy@csgroup.eu
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WRITE_KERN is supposed to overwrite some kernel text, namely
do_overwritten() function.
But at the time being it overwrites do_overwritten() function
descriptor, not function text.
Fix it by dereferencing the function descriptor to obtain
function text pointer. Export dereference_function_descriptor()
for when LKDTM is built as a module.
And make do_overwritten() noinline so that it is really
do_overwritten() which is called by lkdtm_WRITE_KERN().
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/31e58eaffb5bc51c07d8d4891d1982100ade8cfc.1644928018.git.christophe.leroy@csgroup.eu
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LKDTM tests display that the run do_nothing() at a given
address, but in reality do_nothing() is inlined into the
caller.
Force it out of line so that it really runs text at the
displayed address.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/a5dcf4d2088e6aca47ab3b4c6d5c0f7fa064e25a.1644928018.git.christophe.leroy@csgroup.eu
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git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc
Pull char/misc and other driver updates from Greg KH:
"Here is the large set of char, misc, and other "small" driver
subsystem changes for 5.17-rc1.
Lots of different things are in here for char/misc drivers such as:
- habanalabs driver updates
- mei driver updates
- lkdtm driver updates
- vmw_vmci driver updates
- android binder driver updates
- other small char/misc driver updates
Also smaller driver subsystems have also been updated, including:
- fpga subsystem updates
- iio subsystem updates
- soundwire subsystem updates
- extcon subsystem updates
- gnss subsystem updates
- phy subsystem updates
- coresight subsystem updates
- firmware subsystem updates
- comedi subsystem updates
- mhi subsystem updates
- speakup subsystem updates
- rapidio subsystem updates
- spmi subsystem updates
- virtual driver updates
- counter subsystem updates
Too many individual changes to summarize, the shortlog contains the
full details.
All of these have been in linux-next for a while with no reported
issues"
* tag 'char-misc-5.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (406 commits)
counter: 104-quad-8: Fix use-after-free by quad8_irq_handler
dt-bindings: mux: Document mux-states property
dt-bindings: ti-serdes-mux: Add defines for J721S2 SoC
counter: remove old and now unused registration API
counter: ti-eqep: Convert to new counter registration
counter: stm32-lptimer-cnt: Convert to new counter registration
counter: stm32-timer-cnt: Convert to new counter registration
counter: microchip-tcb-capture: Convert to new counter registration
counter: ftm-quaddec: Convert to new counter registration
counter: intel-qep: Convert to new counter registration
counter: interrupt-cnt: Convert to new counter registration
counter: 104-quad-8: Convert to new counter registration
counter: Update documentation for new counter registration functions
counter: Provide alternative counter registration functions
counter: stm32-timer-cnt: Convert to counter_priv() wrapper
counter: stm32-lptimer-cnt: Convert to counter_priv() wrapper
counter: ti-eqep: Convert to counter_priv() wrapper
counter: ftm-quaddec: Convert to counter_priv() wrapper
counter: intel-qep: Convert to counter_priv() wrapper
counter: microchip-tcb-capture: Convert to counter_priv() wrapper
...
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On a kernel without CONFIG_STRICT_KERNEL_RWX, running EXEC_RODATA
test leads to "Illegal instruction" failure.
Looking at the content of rodata_objcopy.o, we see that the
function content zeroes only:
Disassembly of section .rodata:
0000000000000000 <.lkdtm_rodata_do_nothing>:
0: 00 00 00 00 .long 0x0
Add the contents flag in order to keep the content of the section
while renaming it.
Disassembly of section .rodata:
0000000000000000 <.lkdtm_rodata_do_nothing>:
0: 4e 80 00 20 blr
Fixes: e9e08a07385e ("lkdtm: support llvm-objcopy")
Cc: stable@vger.kernel.org
Cc: Kees Cook <keescook@chromium.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/8900731fbc05fb8b0de18af7133a8fc07c3c53a1.1633712176.git.christophe.leroy@csgroup.eu
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The recursive_loop() function is intended as a diagnostic to ensure that
exhausting the stack is caught and mitigated. Currently, it uses
pr_info() to ensure that the function has side effects that the compiler
cannot simply optimize away, so that the stack footprint does not get
reduced inadvertently.
The typical mitigation for stack overflow is to kill the task, and this
overflow may occur inside the call to pr_info(), which means it could be
holding the console lock when this happens. This means that the console
lock is never going to be released again, preventing the diagnostic
prints related to the stack overflow handling from being visible on the
console.
So let's replace the call to pr_info() with a call to
memzero_explicit(), which is not a 'magic' function name like memset()
or memcpy(), which the compiler may replace with plain loads and stores.
To ensure that the stack frames are nested rather than tail-called, put
the call to memzero_explicit() after the recursive call.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20211007081235.382697-1-ardb@kernel.org
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As per Linus's request, remove lkdtm_kernel_info once sufficient
reporting exists in CI systems:
https://lore.kernel.org/lkml/CAHk-=wiFvfkoFixTapvvyPMN9pq5G-+Dys2eSyBa1vzDGAO5+A@mail.gmail.com
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
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Compiling out hash support code when CONFIG_PPC_64S_HASH_MMU=n saves
128kB kernel image size (90kB text) on powernv_defconfig minus KVM,
350kB on pseries_defconfig minus KVM, 40kB on a tiny config.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Fixup defined(ARCH_HAS_MEMREMAP_COMPAT_ALIGN), which needs CONFIG.
Fix radix_enabled() use in setup_initial_memory_limit(). Add some
stubs to reduce number of ifdefs.]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211201144153.2456614-18-npiggin@gmail.com
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This adds Kconfig selection which allows 64s hash MMU support to be
disabled. It can be disabled if radix support is enabled, the minimum
supported CPU type is POWER9 (or higher), and KVM is not selected.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211201144153.2456614-17-npiggin@gmail.com
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Introduce REPORT_STACK_CANARY to check for differing stack canaries
between two processes (i.e. that an architecture is correctly implementing
per-task stack canaries), using the task_struct canary as the hint to
locate in the stack. Requires that one of the processes being tested
not be pid 1.
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20211022223826.330653-3-keescook@chromium.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Using generated/compile.h triggered a full LKDTM rebuild with every
build. Avoid this by using the exported strings instead.
Fixes: b8661450bc7f ("lkdtm: Add kernel version to failure hints")
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20210901233406.2571643-1-keescook@chromium.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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