[ Upstream commit a0fe2c6479aab5723239b315ef1b552673f434a3 ] Use parentheses around uses of the argument in u64_to_user_ptr() to ensure that the cast doesn't apply to part of the argument.
There are existing uses of the macro of the form u64_to_user_ptr(A + B) which expands to (void __user *)(uintptr_t)A + B (the cast applies to the first operand of the addition, the addition is a pointer addition). This happens to still work as intended, the semantic difference doesn't cause a difference in behavior. But I want to use u64_to_user_ptr() with a ternary operator in the argument, like so: u64_to_user_ptr(A ? B : C) This currently doesn't work as intended. Signed-off-by: Jann Horn <[email protected]> Signed-off-by: Borislav Petkov <[email protected]> Reviewed-by: Mukesh Ojha <[email protected]> Cc: Andrei Vagin <[email protected]> Cc: Andrew Morton <[email protected]> Cc: Dan Carpenter <[email protected]> Cc: Greg Kroah-Hartman <[email protected]> Cc: "H. Peter Anvin" <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Jani Nikula <[email protected]> Cc: Kees Cook <[email protected]> Cc: Masahiro Yamada <[email protected]> Cc: NeilBrown <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Qiaowei Ren <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: x86-ml <[email protected]> Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Sasha Levin <[email protected]> --- include/linux/kernel.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/include/linux/kernel.h b/include/linux/kernel.h index 61054f12be7cf..d83fc669eeac7 100644 --- a/include/linux/kernel.h +++ b/include/linux/kernel.h @@ -55,8 +55,8 @@ #define u64_to_user_ptr(x) ( \ { \ - typecheck(u64, x); \ - (void __user *)(uintptr_t)x; \ + typecheck(u64, (x)); \ + (void __user *)(uintptr_t)(x); \ } \ ) -- 2.20.1
