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
...
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
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
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
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
...
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
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
When scsi_dispatch_cmd was moved to scsi_lib.c and made static, some
compilers (i.e., at least gcc 8.4.0) decided to compile this
inline. This is a problem for lkdtm.ko, which inserted a kprobe
on this function for the SCSI_DISPATCH_CMD crashpoint.
Move this crashpoint one function up the call chain to
scsi_queue_rq. Though this is also a static function, it should never be
inlined because it is assigned as a structure entry. Therefore,
kprobe_register should always be able to find it.
Fixes: 82042a2cdb ("scsi: move scsi_dispatch_cmd to scsi_lib.c")
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Kevin Mitchell <kevmitch@arista.com>
Link: https://lore.kernel.org/r/20210819022940.561875-2-kevmitch@arista.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull char / misc driver updates from Greg KH:
"Here is the big set of char / misc and other driver subsystem updates
for 5.14-rc1. Included in here are:
- habanalabs driver updates
- fsl-mc driver updates
- comedi driver updates
- fpga driver updates
- extcon driver updates
- interconnect driver updates
- mei driver updates
- nvmem driver updates
- phy driver updates
- pnp driver updates
- soundwire driver updates
- lots of other tiny driver updates for char and misc drivers
This is looking more and more like the "various driver subsystems
mushed together" tree...
All of these have been in linux-next for a while with no reported
issues"
* tag 'char-misc-5.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (292 commits)
mcb: Use DEFINE_RES_MEM() helper macro and fix the end address
PNP: moved EXPORT_SYMBOL so that it immediately followed its function/variable
bus: mhi: pci-generic: Add missing 'pci_disable_pcie_error_reporting()' calls
bus: mhi: Wait for M2 state during system resume
bus: mhi: core: Fix power down latency
intel_th: Wait until port is in reset before programming it
intel_th: msu: Make contiguous buffers uncached
intel_th: Remove an unused exit point from intel_th_remove()
stm class: Spelling fix
nitro_enclaves: Set Bus Master for the NE PCI device
misc: ibmasm: Modify matricies to matrices
misc: vmw_vmci: return the correct errno code
siox: Simplify error handling via dev_err_probe()
fpga: machxo2-spi: Address warning about unused variable
lkdtm/heap: Add init_on_alloc tests
selftests/lkdtm: Enable various testable CONFIGs
lkdtm: Add CONFIG hints in errors where possible
lkdtm: Enable DOUBLE_FAULT on all architectures
lkdtm/heap: Add vmalloc linear overflow test
lkdtm/bugs: XFAIL UNALIGNED_LOAD_STORE_WRITE
...
Pull CFI on arm64 support from Kees Cook:
"This builds on last cycle's LTO work, and allows the arm64 kernels to
be built with Clang's Control Flow Integrity feature. This feature has
happily lived in Android kernels for almost 3 years[1], so I'm excited
to have it ready for upstream.
The wide diffstat is mainly due to the treewide fixing of mismatched
list_sort prototypes. Other things in core kernel are to address
various CFI corner cases. The largest code portion is the CFI runtime
implementation itself (which will be shared by all architectures
implementing support for CFI). The arm64 pieces are Acked by arm64
maintainers rather than coming through the arm64 tree since carrying
this tree over there was going to be awkward.
CFI support for x86 is still under development, but is pretty close.
There are a handful of corner cases on x86 that need some improvements
to Clang and objtool, but otherwise works well.
Summary:
- Clean up list_sort prototypes (Sami Tolvanen)
- Introduce CONFIG_CFI_CLANG for arm64 (Sami Tolvanen)"
* tag 'cfi-v5.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
arm64: allow CONFIG_CFI_CLANG to be selected
KVM: arm64: Disable CFI for nVHE
arm64: ftrace: use function_nocfi for ftrace_call
arm64: add __nocfi to __apply_alternatives
arm64: add __nocfi to functions that jump to a physical address
arm64: use function_nocfi with __pa_symbol
arm64: implement function_nocfi
psci: use function_nocfi for cpu_resume
lkdtm: use function_nocfi
treewide: Change list_sort to use const pointers
bpf: disable CFI in dispatcher functions
kallsyms: strip ThinLTO hashes from static functions
kthread: use WARN_ON_FUNCTION_MISMATCH
workqueue: use WARN_ON_FUNCTION_MISMATCH
module: ensure __cfi_check alignment
mm: add generic function_nocfi macro
cfi: add __cficanonical
add support for Clang CFI
Pull powerpc updates from Michael Ellerman:
- Switch to the generic C VDSO, as well as some cleanups of our VDSO
setup/handling code.
- Support for KUAP (Kernel User Access Prevention) on systems using the
hashed page table MMU, using memory protection keys.
- Better handling of PowerVM SMT8 systems where all threads of a core
do not share an L2, allowing the scheduler to make better scheduling
decisions.
- Further improvements to our machine check handling.
- Show registers when unwinding interrupt frames during stack traces.
- Improvements to our pseries (PowerVM) partition migration code.
- Several series from Christophe refactoring and cleaning up various
parts of the 32-bit code.
- Other smaller features, fixes & cleanups.
Thanks to: Alan Modra, Alexey Kardashevskiy, Andrew Donnellan, Aneesh
Kumar K.V, Ard Biesheuvel, Athira Rajeev, Balamuruhan S, Bill Wendling,
Cédric Le Goater, Christophe Leroy, Christophe Lombard, Colin Ian King,
Daniel Axtens, David Hildenbrand, Frederic Barrat, Ganesh Goudar,
Gautham R. Shenoy, Geert Uytterhoeven, Giuseppe Sacco, Greg Kurz,
Harish, Jan Kratochvil, Jordan Niethe, Kaixu Xia, Laurent Dufour,
Leonardo Bras, Madhavan Srinivasan, Mahesh Salgaonkar, Mathieu
Desnoyers, Nathan Lynch, Nicholas Piggin, Oleg Nesterov, Oliver
O'Halloran, Oscar Salvador, Po-Hsu Lin, Qian Cai, Qinglang Miao, Randy
Dunlap, Ravi Bangoria, Sachin Sant, Sandipan Das, Sebastian Andrzej
Siewior , Segher Boessenkool, Srikar Dronamraju, Tyrel Datwyler, Uwe
Kleine-König, Vincent Stehlé, Youling Tang, and Zhang Xiaoxu.
* tag 'powerpc-5.11-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (304 commits)
powerpc/32s: Fix cleanup_cpu_mmu_context() compile bug
powerpc: Add config fragment for disabling -Werror
powerpc/configs: Add ppc64le_allnoconfig target
powerpc/powernv: Rate limit opal-elog read failure message
powerpc/pseries/memhotplug: Quieten some DLPAR operations
powerpc/ps3: use dma_mapping_error()
powerpc: force inlining of csum_partial() to avoid multiple csum_partial() with GCC10
powerpc/perf: Fix Threshold Event Counter Multiplier width for P10
powerpc/mm: Fix hugetlb_free_pmd_range() and hugetlb_free_pud_range()
KVM: PPC: Book3S HV: Fix mask size for emulated msgsndp
KVM: PPC: fix comparison to bool warning
KVM: PPC: Book3S: Assign boolean values to a bool variable
powerpc: Inline setup_kup()
powerpc/64s: Mark the kuap/kuep functions non __init
KVM: PPC: Book3S HV: XIVE: Add a comment regarding VP numbering
powerpc/xive: Improve error reporting of OPAL calls
powerpc/xive: Simplify xive_do_source_eoi()
powerpc/xive: Remove P9 DD1 flag XIVE_IRQ_FLAG_EOI_FW
powerpc/xive: Remove P9 DD1 flag XIVE_IRQ_FLAG_MASK_FW
powerpc/xive: Remove P9 DD1 flag XIVE_IRQ_FLAG_SHIFT_BUG
...
Pull char / misc driver updates from Greg KH:
"Here is the big char/misc driver update for 5.11-rc1.
Continuing the tradition of previous -rc1 pulls, there seems to be
more and more tiny driver subsystems flowing through this tree.
Lots of different things, all of which have been in linux-next for a
while with no reported issues:
- extcon driver updates
- habannalab driver updates
- mei driver updates
- uio driver updates
- binder fixes and features added
- soundwire driver updates
- mhi bus driver updates
- phy driver updates
- coresight driver updates
- fpga driver updates
- speakup driver updates
- slimbus driver updates
- various small char and misc driver updates"
* tag 'char-misc-5.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (305 commits)
extcon: max77693: Fix modalias string
extcon: fsa9480: Support TI TSU6111 variant
extcon: fsa9480: Rewrite bindings in YAML and extend
dt-bindings: extcon: add binding for TUSB320
extcon: Add driver for TI TUSB320
slimbus: qcom: fix potential NULL dereference in qcom_slim_prg_slew()
siox: Make remove callback return void
siox: Use bus_type functions for probe, remove and shutdown
spmi: Add driver shutdown support
spmi: fix some coding style issues at the spmi core
spmi: get rid of a warning when built with W=1
uio: uio_hv_generic: use devm_kzalloc() for private data alloc
uio: uio_fsl_elbc_gpcm: use device-managed allocators
uio: uio_aec: use devm_kzalloc() for uio_info object
uio: uio_cif: use devm_kzalloc() for uio_info object
uio: uio_netx: use devm_kzalloc() for or uio_info object
uio: uio_mf624: use devm_kzalloc() for uio_info object
uio: uio_sercos3: use device-managed functions for simple allocs
uio: uio_dmem_genirq: finalize conversion of probe to devm_ handlers
uio: uio_dmem_genirq: convert simple allocations to device-managed
...
Building lkdtm with KASAN and Clang 11 or later results in the following
error when attempting to load the module:
kernel tried to execute NX-protected page - exploit attempt? (uid: 0)
BUG: unable to handle page fault for address: ffffffffc019cd70
#PF: supervisor instruction fetch in kernel mode
#PF: error_code(0x0011) - permissions violation
...
RIP: 0010:asan.module_ctor+0x0/0xffffffffffffa290 [lkdtm]
...
Call Trace:
do_init_module+0x17c/0x570
load_module+0xadee/0xd0b0
__x64_sys_finit_module+0x16c/0x1a0
do_syscall_64+0x34/0x50
entry_SYSCALL_64_after_hwframe+0x44/0xa9
The reason is that rodata.o generates a dummy function that lives in
.rodata to validate that .rodata can't be executed; however, Clang 11 adds
KASAN globals support by generating module constructors to initialize
globals redzones. When Clang 11 adds a module constructor to rodata.o, it
is also added to .rodata: any attempt to call it on initialization results
in the above error.
Therefore, disable KASAN instrumentation for rodata.o.
Link: https://lkml.kernel.org/r/20201214191413.3164796-1-elver@google.com
Signed-off-by: Marco Elver <elver@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Once we can't manipulate the address limit, we also can't test what
happens when the manipulation is abused.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
The result may not be intereresting, but not using a set variable
is bad form and causes W=1 kernel builds to complain.
Fixes the following W=1 warning(s):
drivers/misc/lkdtm/bugs.c: In function ‘lkdtm_STACK_GUARD_PAGE_LEADING’:
drivers/misc/lkdtm/bugs.c:331:25: warning: variable ‘byte’ set but not used [-Wunused-but-set-variable]
331 | volatile unsigned char byte;
| ^~~~
drivers/misc/lkdtm/bugs.c: In function ‘lkdtm_STACK_GUARD_PAGE_TRAILING’:
drivers/misc/lkdtm/bugs.c:345:25: warning: variable ‘byte’ set but not used [-Wunused-but-set-variable]
345 | volatile unsigned char byte;
| ^~~~
Cc: Kees Cook <keescook@chromium.org>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20200626130525.389469-5-lee.jones@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
I'd like arch-specific tests to XFAIL when on a mismatched architecture
so that we can more easily compare test coverage across all systems.
Lacking kernel configs or CPU features count as a FAIL, not an XFAIL.
Additionally fixes a build failure under 32-bit UML.
Fixes: b09511c253 ("lkdtm: Add a DOUBLE_FAULT crash type on x86")
Fixes: cea23efb4d ("lkdtm/bugs: Make double-fault test always available")
Fixes: 6cb6982f42 ("lkdtm: arm64: test kernel pointer authentication")
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20200625203704.317097-5-keescook@chromium.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
It seems at least Clang is able to throw away writes it knows are
destined for read-only memory, which makes things like the WRITE_RO test
fail, as the write gets elided. Instead, force the variable to be
volatile, and make similar changes through-out other tests in an effort
to avoid needing to repeat fixing these kinds of problems. Also includes
pr_err() calls in failure paths so that kernel logs are more clear in
the failure case.
Reported-by: Prasad Sodagudi <psodagud@codeaurora.org>
Suggested-by: Sami Tolvanen <samitolvanen@google.com>
Fixes: 9ae113ce5f ("lkdtm: add tests for additional page permissions")
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20200625203704.317097-2-keescook@chromium.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull char/misc driver updates from Greg KH:
"Here is the big set of char/misc/other driver patches for 5.7-rc1.
Lots of things in here, and it's later than expected due to some
reverts to resolve some reported issues. All is now clean with no
reported problems in linux-next.
Included in here is:
- interconnect updates
- mei driver updates
- uio updates
- nvmem driver updates
- soundwire updates
- binderfs updates
- coresight updates
- habanalabs updates
- mhi new bus type and core
- extcon driver updates
- some Kconfig cleanups
- other small misc driver cleanups and updates
As mentioned, all have been in linux-next for a while, and with the
last two reverts, all is calm and good"
* tag 'char-misc-5.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (174 commits)
Revert "driver core: platform: Initialize dma_parms for platform devices"
Revert "amba: Initialize dma_parms for amba devices"
amba: Initialize dma_parms for amba devices
driver core: platform: Initialize dma_parms for platform devices
bus: mhi: core: Drop the references to mhi_dev in mhi_destroy_device()
bus: mhi: core: Initialize bhie field in mhi_cntrl for RDDM capture
bus: mhi: core: Add support for reading MHI info from device
misc: rtsx: set correct pcr_ops for rts522A
speakup: misc: Use dynamic minor numbers for speakup devices
mei: me: add cedar fork device ids
coresight: do not use the BIT() macro in the UAPI header
Documentation: provide IBM contacts for embargoed hardware
nvmem: core: remove nvmem_sysfs_get_groups()
nvmem: core: use is_bin_visible for permissions
nvmem: core: use device_register and device_unregister
nvmem: core: add root_only member to nvmem device struct
extcon: axp288: Add wakeup support
extcon: Mark extcon_get_edev_name() function as exported symbol
extcon: palmas: Hide error messages if gpio returns -EPROBE_DEFER
dt-bindings: extcon: usbc-cros-ec: convert extcon-usbc-cros-ec.txt to yaml format
...
This test is specific for arm64. When in-kernel Pointer Authentication
config is enabled, the return address stored in the stack is signed.
This feature helps in ROP kind of attack. If any parameters used to
generate the pac (<key, sp, lr>) is modified then this will fail in
the authentication stage and will lead to abort.
This test changes the input parameter APIA kernel keys to cause abort.
The pac computed from the new key can be same as last due to hash
collision so this is retried for few times as there is no reliable way
to compare the pacs. Even though this test may fail even after retries
but this may cause authentication failure at a later stage in earlier
function returns.
This test can be invoked as,
echo CORRUPT_PAC > /sys/kernel/debug/provoke-crash/DIRECT
or as below if inserted as a module,
insmod lkdtm.ko cpoint_name=DIRECT cpoint_type=CORRUPT_PAC cpoint_count=1
[ 13.118166] lkdtm: Performing direct entry CORRUPT_PAC
[ 13.118298] lkdtm: Clearing PAC from the return address
[ 13.118466] Unable to handle kernel paging request at virtual address bfff8000108648ec
[ 13.118626] Mem abort info:
[ 13.118666] ESR = 0x86000004
[ 13.118866] EC = 0x21: IABT (current EL), IL = 32 bits
[ 13.118966] SET = 0, FnV = 0
[ 13.119117] EA = 0, S1PTW = 0
Signed-off-by: Amit Daniel Kachhap <amit.kachhap@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
