Re: [PATCH] x86: limit the fs segment to the pointer size

On Wed, 8 Jan 2020 at 04:14, Masahiro Yamada masahiroy@kernel.org wrote:

The fs segment is only used to get the global data pointer. If it is accessed beyond sizeof(new_gd->arch.gd_addr), it is a bug.

To specify the byte-granule limit size, drop the G bit, so the flag field is 0x8093 instead of 0xc093, and set the limit field to sizeof(new_gd->arch.gd_addr) - 1.

Signed-off-by: Masahiro Yamada masahiroy@kernel.org

arch/x86/cpu/i386/cpu.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)

Reviewed-by: Simon Glass sjg@chromium.org