From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932328AbcCDQEN (ORCPT ); Fri, 4 Mar 2016 11:04:13 -0500 Received: from wtarreau.pck.nerim.net ([62.212.114.60]:60734 "EHLO 1wt.eu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758724AbcCDQEJ (ORCPT ); Fri, 4 Mar 2016 11:04:09 -0500 Message-Id: <20160304153001.147215544@1wt.eu> User-Agent: quilt/0.63-1 Date: Fri, 04 Mar 2016 16:30:10 +0100 From: Willy Tarreau To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: "Dmitry V. Levin" , "David S. Miller" , Ben Hutchings , Willy Tarreau Subject: [PATCH 2.6.32 10/55] sparc64: fix incorrect sign extension in sys_sparc64_personality MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 In-Reply-To: <148ee355b419e9976ca727513a1405c8@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. ------------------ From: "Dmitry V. Levin" commit 525fd5a94e1be0776fa652df5c687697db508c91 upstream. The value returned by sys_personality has type "long int". It is saved to a variable of type "int", which is not a problem yet because the type of task_struct->pesonality is "unsigned int". The problem is the sign extension from "int" to "long int" that happens on return from sys_sparc64_personality. For example, a userspace call personality((unsigned) -EINVAL) will result to any subsequent personality call, including absolutely harmless read-only personality(0xffffffff) call, failing with errno set to EINVAL. Signed-off-by: Dmitry V. Levin Signed-off-by: David S. Miller Signed-off-by: Ben Hutchings Signed-off-by: Willy Tarreau --- arch/sparc/kernel/sys_sparc_64.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/sparc/kernel/sys_sparc_64.c b/arch/sparc/kernel/sys_sparc_64.c index cfa0e19..74e579b 100644 --- a/arch/sparc/kernel/sys_sparc_64.c +++ b/arch/sparc/kernel/sys_sparc_64.c @@ -524,7 +524,7 @@ SYSCALL_DEFINE1(sparc64_newuname, struct new_utsname __user *, name) SYSCALL_DEFINE1(sparc64_personality, unsigned long, personality) { - int ret; + long ret; if (current->personality == PER_LINUX32 && personality == PER_LINUX) -- 1.7.12.2.21.g234cd45.dirty