Return-Path: Received: from mail177-1.suw61.mandrillapp.com ([198.2.177.1]:38253 "EHLO mail177-1.suw61.mandrillapp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755831AbcCAX4T (ORCPT ); Tue, 1 Mar 2016 18:56:19 -0500 Received: from pmta06.mandrill.prod.suw01.rsglab.com (127.0.0.1) by mail177-1.suw61.mandrillapp.com id hqom2622rtkj for ; Tue, 1 Mar 2016 23:54:37 +0000 (envelope-from ) From: Greg Kroah-Hartman Subject: [PATCH 4.4 161/342] sparc64: fix incorrect sign extension in sys_sparc64_personality To: Cc: Greg Kroah-Hartman , , "Dmitry V. Levin" , "David S. Miller" Message-Id: <20160301234533.172508413@linuxfoundation.org> In-Reply-To: <20160301234527.990448862@linuxfoundation.org> References: <20160301234527.990448862@linuxfoundation.org> Date: Tue, 01 Mar 2016 23:54:37 +0000 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Sender: stable-owner@vger.kernel.org List-ID: 4.4-stable 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: Greg Kroah-Hartman --- arch/sparc/kernel/sys_sparc_64.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/arch/sparc/kernel/sys_sparc_64.c +++ b/arch/sparc/kernel/sys_sparc_64.c @@ -413,7 +413,7 @@ out: SYSCALL_DEFINE1(sparc64_personality, unsigned long, personality) { - int ret; + long ret; if (personality(current->personality) == PER_LINUX32 && personality(personality) == PER_LINUX)