• Jann Horn's avatar
    x86/extable: Introduce _ASM_EXTABLE_UA for uaccess fixups · 75045f77
    Jann Horn authored
    Currently, most fixups for attempting to access userspace memory are
    handled using _ASM_EXTABLE, which is also used for various other types of
    fixups (e.g. safe MSR access, IRET failures, and a bunch of other things).
    In order to make it possible to add special safety checks to uaccess fixups
    (in particular, checking whether the fault address is actually in
    userspace), introduce a new exception table handler ex_handler_uaccess()
    and wire it up to all the user access fixups (excluding ones that
    already use _ASM_EXTABLE_EX).
    Signed-off-by: default avatarJann Horn <jannh@google.com>
    Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
    Tested-by: default avatarKees Cook <keescook@chromium.org>
    Cc: Andy Lutomirski <luto@kernel.org>
    Cc: kernel-hardening@lists.openwall.com
    Cc: dvyukov@google.com
    Cc: Masami Hiramatsu <mhiramat@kernel.org>
    Cc: "Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com>
    Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
    Cc: "David S. Miller" <davem@davemloft.net>
    Cc: Alexander Viro <viro@zeniv.linux.org.uk>
    Cc: linux-fsdevel@vger.kernel.org
    Cc: Borislav Petkov <bp@alien8.de>
    Link: https://lkml.kernel.org/r/20180828201421.157735-5-jannh@google.com
    75045f77
csum-copy_64.S 3.78 KB