Re: [PATCH 4.9 09/62] kasan: turn on -fsanitize-address-use-after-scope

[Andrey Ryabinin]

On 5/6/19 5:32 PM, Greg Kroah-Hartman wrote:
> From: Andrey Ryabinin <aryabinin@xxxxxxxxxxxxx>
> 
> commit c5caf21ab0cf884ef15b25af234f620e4a233139 upstream.
> 
> In the upcoming gcc7 release, the -fsanitize=kernel-address option at
> first implied new -fsanitize-address-use-after-scope option.  This would
> cause link errors on older kernels because they don't have two new
> functions required for use-after-scope support.  Therefore, gcc7 changed
> default to -fno-sanitize-address-use-after-scope.
> 
> Now the kernel has everything required for that feature since commit
> 828347f8f9a5 ("kasan: support use-after-scope detection").  So, to make it
> work, we just have to enable use-after-scope in CFLAGS.
> 
> Link: http://lkml.kernel.org/r/1481207977-28654-1-git-send-email-aryabinin@xxxxxxxxxxxxx
> Signed-off-by: Andrey Ryabinin <aryabinin@xxxxxxxxxxxxx>
> Acked-by: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
> Cc: Alexander Potapenko <glider@xxxxxxxxxx>
> Cc: Andrey Konovalov <andreyknvl@xxxxxxxxxx>
> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
> Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
> Signed-off-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx>
> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> 
> ---
>  scripts/Makefile.kasan |    2 ++
>  1 file changed, 2 insertions(+)
> 
> --- a/scripts/Makefile.kasan
> +++ b/scripts/Makefile.kasan
> @@ -29,6 +29,8 @@ else
>      endif
>  endif
>  
> +CFLAGS_KASAN += $(call cc-option, -fsanitize-address-use-after-scope)
> +
>  CFLAGS_KASAN_NOSANITIZE := -fno-builtin
>  
>  endif
> 
> 

This shouldn't be in the -stable.