From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933303AbcCGX2s (ORCPT ); Mon, 7 Mar 2016 18:28:48 -0500 Received: from youngberry.canonical.com ([91.189.89.112]:39491 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753969AbcCGWy7 (ORCPT ); Mon, 7 Mar 2016 17:54:59 -0500 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Martin Schwidefsky , Kamal Mostafa Subject: [PATCH 4.2.y-ckt 193/273] s390/compat: correct restore of high gprs on signal return Date: Mon, 7 Mar 2016 14:49:44 -0800 Message-Id: <1457391064-6660-194-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 2.7.0 In-Reply-To: <1457391064-6660-1-git-send-email-kamal@canonical.com> References: <1457391064-6660-1-git-send-email-kamal@canonical.com> X-Extended-Stable: 4.2 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.2.8-ckt5 -stable review patch. If anyone has any objections, please let me know. ---8<------------------------------------------------------------ From: Martin Schwidefsky commit 342300cc9cd3428bc6bfe5809bfcc1b9a0f06702 upstream. git commit 8070361799ae1e3f4ef347bd10f0a508ac10acfb "s390: add support for vector extension" broke 31-bit compat processes in regard to signal handling. The restore_sigregs_ext32() function is used to restore the additional elements from the user space signal frame. Among the additional elements are the upper registers halves for 64-bit register support for 31-bit processes. The copy_from_user that is used to retrieve the high-gprs array from the user stack uses an incorrect length, 8 bytes instead of 64 bytes. This causes incorrect upper register halves to get loaded. Signed-off-by: Martin Schwidefsky Signed-off-by: Kamal Mostafa --- arch/s390/kernel/compat_signal.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/s390/kernel/compat_signal.c b/arch/s390/kernel/compat_signal.c index c78ba51..24b7e55 100644 --- a/arch/s390/kernel/compat_signal.c +++ b/arch/s390/kernel/compat_signal.c @@ -293,7 +293,7 @@ static int restore_sigregs_ext32(struct pt_regs *regs, /* Restore high gprs from signal stack */ if (__copy_from_user(&gprs_high, &sregs_ext->gprs_high, - sizeof(&sregs_ext->gprs_high))) + sizeof(sregs_ext->gprs_high))) return -EFAULT; for (i = 0; i < NUM_GPRS; i++) *(__u32 *)®s->gprs[i] = gprs_high[i]; -- 2.7.0