[PATCH 6.0 0578/1073] fortify: Do not cast to "unsigned char"

Greg Kroah-Hartman
2022-12-28T16:08:48Z

From: Kees Cook <keescook@chromium.org>

[ Upstream commit e9a40e1585d792751d3a122392695e5a53032809 ]

Do not cast to "unsigned char", as this needlessly creates type problems
when attempting builds without -Wno-pointer-sign[1]. The intent of the
cast is to drop possible "const" types.

[1] https://lore.kernel.org/lkml/CAHk-=wgz3Uba8w7kdXhsqR1qvfemYL+OFQdefJnkeqXG8qZ_pA@mail.gmail.com/

Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Fixes: 3009f891bb9f ("fortify: Allow strlen() and strnlen() to pass compile-time known lengths")
Cc: linux-hardening@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
include/linux/fortify-string.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/linux/fortify-string.h b/include/linux/fortify-string.h
index ae076aae9e66..c26160fe2e34 100644
--- a/include/linux/fortify-string.h
+++ b/include/linux/fortify-string.h
@@ -17,7 +17,7 @@ void __write_overflow_field(size_t avail, size_t wanted) __compiletime_warning("

#define __compiletime_strlen(p) \
({ \
- unsigned char *__p = (unsigned char *)(p); \
+ char *__p = (char *)(p); \
size_t __ret = SIZE_MAX; \
size_t __p_size = __builtin_object_size(p, 1); \
if (__p_size != SIZE_MAX && \
--
2.35.1