There wasn't an LKDTM test to distinguish between -fstack-protector and
-fstack-protector-strong in use. This adds CORRUPT_STACK_STRONG to see
the difference. Also adjusts the stack-clobber value to 0xff so execution
won't potentially jump into userspace when the stack protector is missing.
Signed-off-by: Kees Cook <keescook@chromium.org>
Two new tests STACK_GUARD_PAGE_LEADING and STACK_GUARD_PAGE_TRAILING
attempt to read the byte before and after, respectively, of the current
stack frame, which should fault.
Signed-off-by: Kees Cook <keescook@chromium.org>
The existing REFCOUNT_* LKDTM tests were designed only for testing a narrow
portion of CONFIG_REFCOUNT_FULL. This moves the tests to their own file and
expands their testing to poke each boundary condition.
Since the protections (CONFIG_REFCOUNT_FULL and x86-fast) use different
saturation values and reach-zero behavior, those have to be build-time
set so the tests can actually validate things are happening at the
right places.
Notably, the x86-fast protection will fail REFCOUNT_INC_ZERO and
REFCOUNT_ADD_ZERO since those conditions are not checked (only overflow
is critical to protecting refcount_t). CONFIG_REFCOUNT_FULL will warn for
each REFCOUNT_*_NEGATIVE test since it provides zero-pinning behaviors
(which allows it to pass REFCOUNT_INC_ZERO and REFCOUNT_ADD_ZERO).
Signed-off-by: Kees Cook <keescook@chromium.org>
Add a volatile qualifier where a NULL pointer is deliberately
dereferenced to trigger a panic.
Without the volatile qualifier clang will issue the following warning:
"indirection of non-volatile null pointer will be deleted,
not trap [-Wnull-dereference]" and replace the pointer reference
with a __builtin_trap() (which generates a ud2 instruction on x86_64).
Signed-off-by: Michael Davidson <md@google.com>
Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This adds CORRUPT_USER_DS to check that the get_fs() test on syscall
return (via __VERIFY_PRE_USERMODE_STATE) still sees USER_DS. Since
trying to deal with values other than USER_DS and KERNEL_DS across all
architectures in a safe way is not sensible, this sets KERNEL_DS, but
since that could be extremely dangerous if the protection is not present,
it also raises SIGKILL for current, so that no matter what, the process
will die. A successful test will be visible with a BUG(), like all the
other LKDTM tests.
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Here is the big char/misc driver patchset for 4.11-rc1.
Lots of different driver subsystems updated here. Rework for the hyperv
subsystem to handle new platforms better, mei and w1 and extcon driver
updates, as well as a number of other "minor" driver updates. Full
details are in the shortlog below.
All of these have been in linux-next for a while with no reported
issues.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-----BEGIN PGP SIGNATURE-----
iG0EABECAC0WIQT0tgzFv3jCIUoxPcsxR9QN2y37KQUCWK2iRQ8cZ3JlZ0Brcm9h
aC5jb20ACgkQMUfUDdst+ynhFACguVE+/ixj5u5bT5DXQaZNai/6zIAAmgMWwd/t
YTD2cwsJsGbTT1fY3SUe
=CiSI
-----END PGP SIGNATURE-----
Merge tag 'char-misc-4.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc
Pull char/misc driver updates from Greg KH:
"Here is the big char/misc driver patchset for 4.11-rc1.
Lots of different driver subsystems updated here: rework for the
hyperv subsystem to handle new platforms better, mei and w1 and extcon
driver updates, as well as a number of other "minor" driver updates.
All of these have been in linux-next for a while with no reported
issues"
* tag 'char-misc-4.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (169 commits)
goldfish: Sanitize the broken interrupt handler
x86/platform/goldfish: Prevent unconditional loading
vmbus: replace modulus operation with subtraction
vmbus: constify parameters where possible
vmbus: expose hv_begin/end_read
vmbus: remove conditional locking of vmbus_write
vmbus: add direct isr callback mode
vmbus: change to per channel tasklet
vmbus: put related per-cpu variable together
vmbus: callback is in softirq not workqueue
binder: Add support for file-descriptor arrays
binder: Add support for scatter-gather
binder: Add extra size to allocator
binder: Refactor binder_transact()
binder: Support multiple /dev instances
binder: Deal with contexts in debugfs
binder: Support multiple context managers
binder: Split flat_binder_object
auxdisplay: ht16k33: remove private workqueue
auxdisplay: ht16k33: rework input device initialization
...
After the latest change to make sure the compiler actually does a memset,
it is now smart enough to flag the stack overflow at compile time,
at least with gcc-7.0:
drivers/misc/lkdtm_bugs.c: In function 'lkdtm_CORRUPT_STACK':
drivers/misc/lkdtm_bugs.c:88:144: warning: 'memset' writing 64 bytes into a region of size 8 overflows the destination [-Wstringop-overflow=]
To outsmart the compiler again, this moves the memset into a noinline
function where (for now) it doesn't see that we intentionally write
broken code here.
Fixes: c55d240003 ("lkdtm: Prevent the compiler from optimising lkdtm_CORRUPT_STACK()")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Here's the big char/misc driver patches for 4.10-rc1. Lots of tiny
changes over lots of "minor" driver subsystems, the largest being some
new FPGA drivers. Other than that, a few other new drivers, but no new
driver subsystems added for this kernel cycle, a nice change.
All of these have been in linux-next with no reported issues.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-----BEGIN PGP SIGNATURE-----
iG0EABECAC0WIQT0tgzFv3jCIUoxPcsxR9QN2y37KQUCWFAtwA8cZ3JlZ0Brcm9h
aC5jb20ACgkQMUfUDdst+ykyCgCeJn36u1AsBi7qZ3u/1hwD8k56s2IAnRo6U31r
WW65YcNTK7qYXqNbfgIa
=/t/V
-----END PGP SIGNATURE-----
Merge tag 'char-misc-4.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc
Pull char/misc driver updates from Greg KH:
"Here's the big char/misc driver patches for 4.10-rc1. Lots of tiny
changes over lots of "minor" driver subsystems, the largest being some
new FPGA drivers. Other than that, a few other new drivers, but no new
driver subsystems added for this kernel cycle, a nice change.
All of these have been in linux-next with no reported issues"
* tag 'char-misc-4.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (107 commits)
uio-hv-generic: store physical addresses instead of virtual
Tools: hv: kvp: configurable external scripts path
uio-hv-generic: new userspace i/o driver for VMBus
vmbus: add support for dynamic device id's
hv: change clockevents unbind tactics
hv: acquire vmbus_connection.channel_mutex in vmbus_free_channels()
hyperv: Fix spelling of HV_UNKOWN
mei: bus: enable non-blocking RX
mei: fix the back to back interrupt handling
mei: synchronize irq before initiating a reset.
VME: Remove shutdown entry from vme_driver
auxdisplay: ht16k33: select framebuffer helper modules
MAINTAINERS: add git url for fpga
fpga: Clarify how write_init works streaming modes
fpga zynq: Fix incorrect ISR state on bootup
fpga zynq: Remove priv->dev
fpga zynq: Add missing \n to messages
fpga: Add COMPILE_TEST to all drivers
uio: pruss: add clk_disable()
char/pcmcia: add some error checking in scr24x_read()
...
At least on powerpc with GCC 6, the compiler is smart enough to optimise
lkdtm_CORRUPT_STACK() into an empty function that just returns.
If we print the buffer after we've written to it that prevents the
compiler from optimising away data and the memset().
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When building under CONFIG_DEBUG_LIST, list addition and removal will be
sanity-checked. This validates that the check is working as expected by
setting up classic corruption attacks against list manipulations, available
with the new lkdtm tests CORRUPT_LIST_ADD and CORRUPT_LIST_DEL.
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Rik van Riel <riel@redhat.com>
When building under W=1, the lack of lkdtm.h in lkdtm_usercopy.c and
lkdtm_rodata.c was discovered. This fixes the issue and consolidates
the common header and the pr_fmt macro for simplicity and regularity
across each test source file.
Signed-off-by: Kees Cook <keescook@chromium.org>
This splits all the remaining tests from lkdtm_core.c into the new
lkdtm_bugs.c file to help separate things better for readability.
Signed-off-by: Kees Cook <keescook@chromium.org>
Kees Cook