From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752655AbaIGUF0 (ORCPT ); Sun, 7 Sep 2014 16:05:26 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:39715 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751496AbaIGUFY (ORCPT ); Sun, 7 Sep 2014 16:05:24 -0400 Message-ID: <1410120305.6822.9.camel@decadent.org.uk> Subject: [PATCH RESEND] x86: Reject x32 executables if x32 ABI not supported From: Ben Hutchings To: Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" Cc: LKML Date: Sun, 07 Sep 2014 21:05:05 +0100 Content-Type: multipart/signed; micalg="pgp-sha512"; protocol="application/pgp-signature"; boundary="=-uAY0rl8HUPqi3/1ZBRRl" X-Mailer: Evolution 3.12.5-1+b1 Mime-Version: 1.0 X-SA-Exim-Connect-IP: 192.168.4.249 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --=-uAY0rl8HUPqi3/1ZBRRl Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable It is currently possible to execve() an x32 executable on an x86_64 kernel that has only ia32 compat enabled. However all its syscalls will fail, even _exit(). This usually causes it to segfault. Change the ELF compat architecture check so that x32 executables are rejected if we don't support the x32 ABI. Signed-off-by: Ben Hutchings --- arch/x86/include/asm/elf.h | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/arch/x86/include/asm/elf.h b/arch/x86/include/asm/elf.h index 1a055c8..ca3347a 100644 --- a/arch/x86/include/asm/elf.h +++ b/arch/x86/include/asm/elf.h @@ -160,8 +160,9 @@ do { \ #define elf_check_arch(x) \ ((x)->e_machine =3D=3D EM_X86_64) =20 -#define compat_elf_check_arch(x) \ - (elf_check_arch_ia32(x) || (x)->e_machine =3D=3D EM_X86_64) +#define compat_elf_check_arch(x) \ + (elf_check_arch_ia32(x) || \ + (IS_ENABLED(CONFIG_X86_X32_ABI) && (x)->e_machine =3D=3D EM_X86_64)) =20 #if __USER32_DS !=3D __USER_DS # error "The following code assumes __USER32_DS =3D=3D __USER_DS" --=20 Ben Hutchings Experience is directly proportional to the value of equipment destroyed. - Carolyn Scheppne= r --=-uAY0rl8HUPqi3/1ZBRRl Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQIVAwUAVAy6d+e/yOyVhhEJAQqZXw//axU1vljWQQlJXSBuda89IssfBU/okwSj UvWFwRXHCaMkQUjzqGQqUnxNWYI3Ayhfou1yoEZGSpwekahVR9T91K8wO4zj5jlu C7bUq4lFHO6w8mdoGOAEtMsk1pEE4HJ3G2Evv0l200arcqH6ZcEOUDmH8vWZiMMC kT8iBC6yY9/ZdjFKk1xxzGOzCLKVq7wRhmNsEFEWu74jE4xM1jprUHAbQ+0rnmaA 9Gy14yo93vHXWsuSyqc5WHqB2/RMNolQBUmDeF50d16x6al8ITJi6C4z9EEZt/E7 d7W3pt8l4C0FV+w9C6cIaBqJQszsAx8CkoqqiRKTS0bdMklMtJeAhO/pHSM9y56X ENx2scfLcst7jge7AtNKRJR7trVIJ2s0c4dGz20UvkgSNoFlt4DwADIT4TUGzOA2 /0c3dVVCCybi3UNYe8G3bdFSmLOfwINehwfnHhogPh0JhTrKXfdZWHDWY2MH6RZ+ KYxe24VLiV5Uosy5Z4Oca8bBunTTU2SZ2L8wHD8PZpsOx9Teq9MayNJqEFfQa+fQ ZMl+p41HVLyIw6fx+Hbh3CTimiEP/nY7LPLcTArHgsKrPqp6gPf5fBDaAEkY24gv +vUGSzfn116kbczHIJ+n/Y4l5uQ7tp+CfhwCx5AMFPm9YQzOQ63M6IMisYrZ6WJO 00wxJLpjtyU= =j3a8 -----END PGP SIGNATURE----- --=-uAY0rl8HUPqi3/1ZBRRl--