From patchwork Tue Nov 13 05:49:09 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sasha Levin X-Patchwork-Id: 996819 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=linux-cifs-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=none dis=none) header.from=kernel.org Authentication-Results: ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.b="zVebQ5V5"; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 42vHFy2spjz9s3q for ; Tue, 13 Nov 2018 17:07:02 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731262AbeKMQD1 (ORCPT ); Tue, 13 Nov 2018 11:03:27 -0500 Received: from mail.kernel.org ([198.145.29.99]:59872 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727555AbeKMPqT (ORCPT ); Tue, 13 Nov 2018 10:46:19 -0500 Received: from sasha-vm.mshome.net (unknown [64.114.255.114]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 87E2622507; Tue, 13 Nov 2018 05:49:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1542088191; bh=mzwDGY25cvtL7/0M3SHkKaRKIfCj0un1keoSROZT13A=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=zVebQ5V5NiqA4s/pxNkU7P/gQ57kaX/3t3k4EOBxaQf+iWgNTA6GoQaclIo116UlH wqtSJ+0g6Dluldqcm7bgP9DY0odeSsnkaAmeQo0Pl1LiGC4lLVdPMrx+EDnWO+LNEx BnTG9hIWG1xMy603f/OWZVFaPJYEljTKYZWBTBYs= From: Sasha Levin To: stable@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Ronnie Sahlberg , Steve French , Sasha Levin , linux-cifs@vger.kernel.org Subject: [PATCH AUTOSEL 4.19 03/44] cifs: fix return value for cifs_listxattr Date: Tue, 13 Nov 2018 00:49:09 -0500 Message-Id: <20181113054950.77898-3-sashal@kernel.org> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20181113054950.77898-1-sashal@kernel.org> References: <20181113054950.77898-1-sashal@kernel.org> Sender: linux-cifs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-cifs@vger.kernel.org From: Ronnie Sahlberg [ Upstream commit 0c5d6cb6643f48ad3775322f3ebab6c7eb67484e ] If the application buffer was too small to fit all the names we would still count the number of bytes and return this for listxattr. This would then trigger a BUG in usercopy.c Fix the computation of the size so that we return -ERANGE correctly when the buffer is too small. This fixes the kernel BUG for xfstest generic/377 Signed-off-by: Ronnie Sahlberg Signed-off-by: Steve French Reviewed-by: Aurelien Aptel Signed-off-by: Sasha Levin --- fs/cifs/smb2ops.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c index 89985a0a6819..812da3e56a22 100644 --- a/fs/cifs/smb2ops.c +++ b/fs/cifs/smb2ops.c @@ -686,6 +686,7 @@ move_smb2_ea_to_cifs(char *dst, size_t dst_size, int rc = 0; unsigned int ea_name_len = ea_name ? strlen(ea_name) : 0; char *name, *value; + size_t buf_size = dst_size; size_t name_len, value_len, user_name_len; while (src_size > 0) { @@ -721,9 +722,10 @@ move_smb2_ea_to_cifs(char *dst, size_t dst_size, /* 'user.' plus a terminating null */ user_name_len = 5 + 1 + name_len; - rc += user_name_len; - - if (dst_size >= user_name_len) { + if (buf_size == 0) { + /* skip copy - calc size only */ + rc += user_name_len; + } else if (dst_size >= user_name_len) { dst_size -= user_name_len; memcpy(dst, "user.", 5); dst += 5; @@ -731,8 +733,7 @@ move_smb2_ea_to_cifs(char *dst, size_t dst_size, dst += name_len; *dst = 0; ++dst; - } else if (dst_size == 0) { - /* skip copy - calc size only */ + rc += user_name_len; } else { /* stop before overrun buffer */ rc = -ERANGE;