treewide: Drop function_nocfi

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

lkdtm/usercopy: Check vmalloc and >0-order folios

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>

lkdtm/usercopy: Rename "heap" to "slab"

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>

lkdtm: Move crashtype definitions into each category

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>

lkdtm/usercopy: Expand size of "out of frame" object

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>

lkdtm: Add CONFIG hints in errors where possible

For various failure conditions, try to include some details about where
to look for reasons about the failure.

Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20210623203936.3151093-8-keescook@chromium.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

lkdtm: use function_nocfi

To ensure we take the actual address of a function in kernel text,
use function_nocfi. Otherwise, with CONFIG_CFI_CLANG, the compiler
replaces the address with a pointer to the CFI jump table, which is
actually in the module when compiled with CONFIG_LKDTM=m.

Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Acked-by: Kees Cook <keescook@chromium.org>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20210408182843.1754385-11-samitolvanen@google.com

lkdtm: remove set_fs-based tests

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>

lkdtm: Avoid more compiler optimizations for bad writes

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: 9ae113ce5faf ("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>

lkdtm/usercopy: Moves the KERNEL_DS test to non-canonical

The prior implementation of the KERNEL_DS fault checking would work on
any unmapped kernel address, but this was narrowed to the non-canonical
range instead. This adjusts the LKDTM test to match.

Fixes: 00c42373d397 ("x86-64: add warning for non-canonical user access address dereferences")
Signed-off-by: Kees Cook <keescook@chromium.org>

misc: lkdtm: fixed static variable initialization

Resolved "ERROR: do not initialise statics to 0"

Signed-off-by: Parth Y Shah <sparth1292@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

lkdtm: Test copy_to_user() on bad kernel pointer under KERNEL_DS

Test whether the kernel WARN()s when, under KERNEL_DS, a bad kernel pointer
is used as "userspace" pointer. Should normally be used in "DIRECT" mode.

Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Kees Cook <keescook@chromium.org>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: kernel-hardening@lists.openwall.com
Cc: dvyukov@google.com
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: "Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Cc: Borislav Petkov <bp@alien8.de>
Link: https://lkml.kernel.org/r/20180828201421.157735-8-jannh@google.com

lkdtm: Relocate code to subdirectory

The LKDTM modules keep expanding, and it's getting weird to have each file
get a prefix. Instead, move to a subdirectory for cleaner handling.

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>