Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759403AbcCDJUb (ORCPT ); Fri, 4 Mar 2016 04:20:31 -0500 Received: from mx2.suse.de ([195.135.220.15]:59756 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759068AbcCDJDm (ORCPT ); Fri, 4 Mar 2016 04:03:42 -0500 X-Amavis-Alert: BAD HEADER SECTION, Duplicate header field: "References" From: Jiri Slaby To: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org, "Dmitry V. Levin" , "David S . Miller" , Jiri Slaby Subject: [PATCH 3.12 091/116] sparc64: fix incorrect sign extension in sys_sparc64_personality Date: Fri, 4 Mar 2016 10:02:16 +0100 Message-Id: X-Mailer: git-send-email 2.7.2 In-Reply-To: References: In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1388 Lines: 41 From: "Dmitry V. Levin" 3.12-stable review patch. If anyone has any objections, please let me know. =============== 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: Jiri Slaby --- 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 d188c591f2d6..608f9390396e 100644 --- a/arch/sparc/kernel/sys_sparc_64.c +++ b/arch/sparc/kernel/sys_sparc_64.c @@ -411,7 +411,7 @@ out: SYSCALL_DEFINE1(sparc64_personality, unsigned long, personality) { - int ret; + long ret; if (personality(current->personality) == PER_LINUX32 && personality(personality) == PER_LINUX) -- 2.7.2