linux-toradex.git/lib/strscpy_kunit.c, branch v6.2-rc2 Linux kernel for Apalis and Colibri modules fortify: Short-circuit known-safe calls to strscpy() 2022-11-01T17:04:52+00:00 Kees Cook keescook@chromium.org 2022-10-02T16:17:03+00:00 62e1cbfc5d795381a0f237ae7ee229a92d51cf9e Replacing compile-time safe calls of strcpy()-related functions with strscpy() was always calling the full strscpy() logic when a builtin would be better. For example: char buf[16]; strcpy(buf, "yes"); would reduce to __builtin_memcpy(buf, "yes", 4), but not if it was: strscpy(buf, yes, sizeof(buf)); Fix this by checking if all sizes are known at compile-time. Cc: linux-hardening@vger.kernel.org Tested-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Kees Cook <keescook@chromium.org> 
Replacing compile-time safe calls of strcpy()-related functions with
strscpy() was always calling the full strscpy() logic when a builtin
would be better. For example:

	char buf[16];
	strcpy(buf, "yes");

would reduce to __builtin_memcpy(buf, "yes", 4), but not if it was:

	strscpy(buf, yes, sizeof(buf));

Fix this by checking if all sizes are known at compile-time.

Cc: linux-hardening@vger.kernel.org
Tested-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
string: Convert strscpy() self-test to KUnit 2022-11-01T17:04:52+00:00 Kees Cook keescook@chromium.org 2022-10-02T16:51:46+00:00 41eefc46a3a4682976afb5f8c4b9734ed6bfd406 Convert the strscpy() self-test to a KUnit test. Cc: David Gow <davidgow@google.com> Cc: Tobin C. Harding <tobin@kernel.org> Tested-by: Nathan Chancellor <nathan@kernel.org> Link: https://lore.kernel.org/lkml/Y072ZMk/hNkfwqMv@dev-arch.thelio-3990X Signed-off-by: Kees Cook <keescook@chromium.org> 
Convert the strscpy() self-test to a KUnit test.

Cc: David Gow <davidgow@google.com>
Cc: Tobin C. Harding <tobin@kernel.org>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Link: https://lore.kernel.org/lkml/Y072ZMk/hNkfwqMv@dev-arch.thelio-3990X
Signed-off-by: Kees Cook <keescook@chromium.org>