From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932754AbZKFWdg (ORCPT ); Fri, 6 Nov 2009 17:33:36 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932472AbZKFWXL (ORCPT ); Fri, 6 Nov 2009 17:23:11 -0500 Received: from kroah.org ([198.145.64.141]:56932 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760197AbZKFWXG (ORCPT ); Fri, 6 Nov 2009 17:23:06 -0500 X-Mailbox-Line: From gregkh@mini.kroah.org Fri Nov 6 14:15:46 2009 Message-Id: <20091106221546.018042424@mini.kroah.org> User-Agent: quilt/0.48-1 Date: Fri, 06 Nov 2009 14:14:51 -0800 From: Greg KH To: linux-kernel@vger.kernel.org, stable@kernel.org Cc: stable-review@kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Jan Beulich , Roland McGrath , Ingo Molnar Subject: [53/99] x86-64: Fix register leak in 32-bit syscall audting References: <20091106221358.309857998@mini.kroah.org> Content-Disposition: inline; filename=x86-64-fix-register-leak-in-32-bit-syscall-audting.patch In-Reply-To: <20091106221850.GA15408@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2.6.31-stable review patch. If anyone has any objections, please let us know. ------------------ From: Jan Beulich commit 81766741fe1eee3884219e8daaf03f466f2ed52f upstream. Restoring %ebp after the call to audit_syscall_exit() is not only unnecessary (because the register didn't get clobbered), but in the sysenter case wasn't even doing the right thing: It loaded %ebp from a location below the top of stack (RBP < ARGOFFSET), i.e. arbitrary kernel data got passed back to user mode in the register. Signed-off-by: Jan Beulich Acked-by: Roland McGrath LKML-Reference: <4AE5CC4D020000780001BD13@vpn.id2.novell.com> Signed-off-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman --- arch/x86/ia32/ia32entry.S | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) --- a/arch/x86/ia32/ia32entry.S +++ b/arch/x86/ia32/ia32entry.S @@ -204,7 +204,7 @@ sysexit_from_sys_call: movl RDI-ARGOFFSET(%rsp),%r8d /* reload 5th syscall arg */ .endm - .macro auditsys_exit exit,ebpsave=RBP + .macro auditsys_exit exit testl $(_TIF_ALLWORK_MASK & ~_TIF_SYSCALL_AUDIT),TI_flags(%r10) jnz ia32_ret_from_sys_call TRACE_IRQS_ON @@ -217,7 +217,6 @@ sysexit_from_sys_call: call audit_syscall_exit GET_THREAD_INFO(%r10) movl RAX-ARGOFFSET(%rsp),%eax /* reload syscall return value */ - movl \ebpsave-ARGOFFSET(%rsp),%ebp /* reload user register value */ movl $(_TIF_ALLWORK_MASK & ~_TIF_SYSCALL_AUDIT),%edi cli TRACE_IRQS_OFF @@ -351,7 +350,7 @@ cstar_auditsys: jmp cstar_dispatch sysretl_audit: - auditsys_exit sysretl_from_sys_call, RCX /* user %ebp in RCX slot */ + auditsys_exit sysretl_from_sys_call #endif cstar_tracesys: