From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752835AbaKPWO3 (ORCPT ); Sun, 16 Nov 2014 17:14:29 -0500 Received: from 1wt.eu ([62.212.114.60]:47853 "EHLO 1wt.eu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751180AbaKPWA2 (ORCPT ); Sun, 16 Nov 2014 17:00:28 -0500 Message-Id: <20141116215328.693816276@1wt.eu> User-Agent: quilt/0.48-1 Date: Sun, 16 Nov 2014 22:53:29 +0100 From: Willy Tarreau To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Roland McGrath , Andy Lutomirski , "H. Peter Anvin" , Willy Tarreau Subject: [ 01/48] x86_32, entry: Do syscall exit work on badsys In-Reply-To: <28c765bc23bd4bae1611534e510f49f8@local> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2.6.32-longterm review patch. If anyone has any objections, please let me know. ------------------ (CVE-2014-4508) From: Andy Lutomirski The bad syscall nr paths are their own incomprehensible route through the entry control flow. Rearrange them to work just like syscalls that return -ENOSYS. This fixes an OOPS in the audit code when fast-path auditing is enabled and sysenter gets a bad syscall nr (CVE-2014-4508). This has probably been broken since Linux 2.6.27: af0575bba0 i386 syscall audit fast-path Cc: stable@vger.kernel.org Cc: Roland McGrath Reported-by: Toralf Förster Signed-off-by: Andy Lutomirski Link: http://lkml.kernel.org/r/e09c499eade6fc321266dd6b54da7beb28d6991c.1403558229.git.luto@amacapital.net Signed-off-by: H. Peter Anvin (cherry picked from commit 554086d85e71f30abe46fc014fea31929a7c6a8a) [WT: this fix is incorrect and requires the two following patches] Signed-off-by: Willy Tarreau --- arch/x86/kernel/entry_32.S | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/arch/x86/kernel/entry_32.S b/arch/x86/kernel/entry_32.S index c097e7d..40a0d02 100644 --- a/arch/x86/kernel/entry_32.S +++ b/arch/x86/kernel/entry_32.S @@ -445,9 +445,10 @@ sysenter_past_esp: jnz sysenter_audit sysenter_do_call: cmpl $(nr_syscalls), %eax - jae syscall_badsys + jae sysenter_badsys call *sys_call_table(,%eax,4) movl %eax,PT_EAX(%esp) +sysenter_after_call: LOCKDEP_SYS_EXIT DISABLE_INTERRUPTS(CLBR_ANY) TRACE_IRQS_OFF @@ -702,7 +703,12 @@ END(syscall_fault) syscall_badsys: movl $-ENOSYS,PT_EAX(%esp) - jmp resume_userspace + jmp syscall_exit +END(syscall_badsys) + +sysenter_badsys: + movl $-ENOSYS,PT_EAX(%esp) + jmp sysenter_after_call END(syscall_badsys) CFI_ENDPROC -- 1.7.12.2.21.g234cd45.dirty