From patchwork Wed Sep 27 06:20:01 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ronnie Sahlberg X-Patchwork-Id: 9973155 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id E5F246037F for ; Wed, 27 Sep 2017 06:20:21 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id D3F532909D for ; Wed, 27 Sep 2017 06:20:19 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id C5C87290A1; Wed, 27 Sep 2017 06:20:19 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 639AE2909D for ; Wed, 27 Sep 2017 06:20:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750846AbdI0GUP (ORCPT ); Wed, 27 Sep 2017 02:20:15 -0400 Received: from mx1.redhat.com ([209.132.183.28]:33282 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750829AbdI0GUO (ORCPT ); Wed, 27 Sep 2017 02:20:14 -0400 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id A2D6313A5D; Wed, 27 Sep 2017 06:20:14 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com A2D6313A5D Authentication-Results: ext-mx05.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx05.extmail.prod.ext.phx2.redhat.com; spf=fail smtp.mailfrom=lsahlber@redhat.com Received: from test1190.test.redhat.com (vpn2-54-121.bne.redhat.com [10.64.54.121]) by smtp.corp.redhat.com (Postfix) with ESMTP id B687B7E2FD; Wed, 27 Sep 2017 06:20:12 +0000 (UTC) From: Ronnie Sahlberg To: linux-cifs Cc: Steve French Subject: [PATCH] cifs: handle large EA requests more gracefully in smb2+ Date: Wed, 27 Sep 2017 16:20:01 +1000 Message-Id: <20170927062001.979-1-lsahlber@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.29]); Wed, 27 Sep 2017 06:20:14 +0000 (UTC) Sender: linux-cifs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-cifs@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Update update reading the EA using increasingly larger buffer sizes until the response will fit in the buffer, or we exceed the (arbitrary) maximum set to 64kb. Without this change, a user is able to add more and more EAs using setfattr until the point where the total space of all EAs exceed 2kb at which point the user can no longer list the EAs at all and getfattr will abort with an error. The maximum is currently set to 64kb almost arbitrarily. 64kb is the maximum size of all xattrs under XFS so at least for samba + XFS (or EXT4) servers we will not be able to write so many EAs that we no longer can list them any more. The same issue still exists for EAs in SMB1. Signed-off-by: Ronnie Sahlberg --- fs/cifs/smb2maperror.c | 2 +- fs/cifs/smb2ops.c | 31 +++++++++++++++++++++++++------ fs/cifs/smb2pdu.c | 6 +++--- fs/cifs/smb2pdu.h | 3 ++- fs/cifs/smb2proto.h | 1 + 5 files changed, 32 insertions(+), 11 deletions(-) diff --git a/fs/cifs/smb2maperror.c b/fs/cifs/smb2maperror.c index 7ca9808a0daa..62c88dfed57b 100644 --- a/fs/cifs/smb2maperror.c +++ b/fs/cifs/smb2maperror.c @@ -214,7 +214,7 @@ static const struct status_to_posix_error smb2_error_map_table[] = { {STATUS_DATATYPE_MISALIGNMENT, -EIO, "STATUS_DATATYPE_MISALIGNMENT"}, {STATUS_BREAKPOINT, -EIO, "STATUS_BREAKPOINT"}, {STATUS_SINGLE_STEP, -EIO, "STATUS_SINGLE_STEP"}, - {STATUS_BUFFER_OVERFLOW, -EIO, "STATUS_BUFFER_OVERFLOW"}, + {STATUS_BUFFER_OVERFLOW, -E2BIG, "STATUS_BUFFER_OVERFLOW"}, {STATUS_NO_MORE_FILES, -ENODATA, "STATUS_NO_MORE_FILES"}, {STATUS_WAKE_SYSTEM_DEBUGGER, -EIO, "STATUS_WAKE_SYSTEM_DEBUGGER"}, {STATUS_HANDLES_CLOSED, -EIO, "STATUS_HANDLES_CLOSED"}, diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c index 0dafdbae1f8c..bdb963d0ba32 100644 --- a/fs/cifs/smb2ops.c +++ b/fs/cifs/smb2ops.c @@ -522,6 +522,7 @@ smb2_query_eas(const unsigned int xid, struct cifs_tcon *tcon, struct cifs_open_parms oparms; struct cifs_fid fid; struct smb2_file_full_ea_info *smb2_data; + int ea_buf_size = SMB2_MIN_EA_BUF; utf16_path = cifs_convert_path_to_utf16(path, cifs_sb); if (!utf16_path) @@ -541,14 +542,32 @@ smb2_query_eas(const unsigned int xid, struct cifs_tcon *tcon, return rc; } - smb2_data = kzalloc(SMB2_MAX_EA_BUF, GFP_KERNEL); - if (smb2_data == NULL) { - SMB2_close(xid, tcon, fid.persistent_fid, fid.volatile_fid); - return -ENOMEM; + while (1) { + smb2_data = kzalloc(ea_buf_size, GFP_KERNEL); + if (smb2_data == NULL) { + SMB2_close(xid, tcon, fid.persistent_fid, + fid.volatile_fid); + return -ENOMEM; + } + + rc = SMB2_query_eas(xid, tcon, fid.persistent_fid, + fid.volatile_fid, + ea_buf_size, smb2_data); + + if (rc != -E2BIG) + break; + + kfree(smb2_data); + ea_buf_size <<= 1; + + if (ea_buf_size > SMB2_MAX_EA_BUF) { + cifs_dbg(VFS, "EA size is too large\n"); + SMB2_close(xid, tcon, fid.persistent_fid, + fid.volatile_fid); + return -ENOMEM; + } } - rc = SMB2_query_eas(xid, tcon, fid.persistent_fid, fid.volatile_fid, - smb2_data); SMB2_close(xid, tcon, fid.persistent_fid, fid.volatile_fid); if (!rc) diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c index 6f0e6343c15e..ba3865b338d8 100644 --- a/fs/cifs/smb2pdu.c +++ b/fs/cifs/smb2pdu.c @@ -2233,12 +2233,12 @@ query_info(const unsigned int xid, struct cifs_tcon *tcon, } int SMB2_query_eas(const unsigned int xid, struct cifs_tcon *tcon, - u64 persistent_fid, u64 volatile_fid, - struct smb2_file_full_ea_info *data) + u64 persistent_fid, u64 volatile_fid, + int ea_buf_size, struct smb2_file_full_ea_info *data) { return query_info(xid, tcon, persistent_fid, volatile_fid, FILE_FULL_EA_INFORMATION, SMB2_O_INFO_FILE, 0, - SMB2_MAX_EA_BUF, + ea_buf_size, sizeof(struct smb2_file_full_ea_info), (void **)&data, NULL); diff --git a/fs/cifs/smb2pdu.h b/fs/cifs/smb2pdu.h index 6c9653a130c8..4c155b95b558 100644 --- a/fs/cifs/smb2pdu.h +++ b/fs/cifs/smb2pdu.h @@ -1178,7 +1178,8 @@ struct smb2_file_link_info { /* encoding of request for level 11 */ char FileName[0]; /* Name to be assigned to new link */ } __packed; /* level 11 Set */ -#define SMB2_MAX_EA_BUF 2048 +#define SMB2_MIN_EA_BUF 2048 +#define SMB2_MAX_EA_BUF 65536 struct smb2_file_full_ea_info { /* encoding of response for level 15 */ __le32 next_entry_offset; diff --git a/fs/cifs/smb2proto.h b/fs/cifs/smb2proto.h index 003217099ef3..e9ab5227e7a8 100644 --- a/fs/cifs/smb2proto.h +++ b/fs/cifs/smb2proto.h @@ -134,6 +134,7 @@ extern int SMB2_flush(const unsigned int xid, struct cifs_tcon *tcon, u64 persistent_file_id, u64 volatile_file_id); extern int SMB2_query_eas(const unsigned int xid, struct cifs_tcon *tcon, u64 persistent_file_id, u64 volatile_file_id, + int ea_buf_size, struct smb2_file_full_ea_info *data); extern int SMB2_query_info(const unsigned int xid, struct cifs_tcon *tcon, u64 persistent_file_id, u64 volatile_file_id,