From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id ACC0CC5CFE7 for ; Tue, 10 Jul 2018 18:31:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 704022083E for ; Tue, 10 Jul 2018 18:31:59 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 704022083E Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388539AbeGJScJ (ORCPT ); Tue, 10 Jul 2018 14:32:09 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:47432 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732845AbeGJScH (ORCPT ); Tue, 10 Jul 2018 14:32:07 -0400 Received: from localhost (LFbn-1-12247-202.w90-92.abo.wanadoo.fr [90.92.61.202]) by mail.linuxfoundation.org (Postfix) with ESMTPSA id 18312E78; Tue, 10 Jul 2018 18:31:54 +0000 (UTC) From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jianhong Yin , Stefano Brivio , Steve French Subject: [PATCH 4.14 12/53] cifs: Fix slab-out-of-bounds in send_set_info() on SMB2 ACE setting Date: Tue, 10 Jul 2018 20:24:48 +0200 Message-Id: <20180710182459.628491182@linuxfoundation.org> X-Mailer: git-send-email 2.18.0 In-Reply-To: <20180710182458.736721865@linuxfoundation.org> References: <20180710182458.736721865@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Stefano Brivio commit f46ecbd97f508e68a7806291a139499794874f3d upstream. A "small" CIFS buffer is not big enough in general to hold a setacl request for SMB2, and we end up overflowing the buffer in send_set_info(). For instance: # mount.cifs //127.0.0.1/test /mnt/test -o username=test,password=test,nounix,cifsacl # touch /mnt/test/acltest # getcifsacl /mnt/test/acltest REVISION:0x1 CONTROL:0x9004 OWNER:S-1-5-21-2926364953-924364008-418108241-1000 GROUP:S-1-22-2-1001 ACL:S-1-5-21-2926364953-924364008-418108241-1000:ALLOWED/0x0/0x1e01ff ACL:S-1-22-2-1001:ALLOWED/0x0/R ACL:S-1-22-2-1001:ALLOWED/0x0/R ACL:S-1-5-21-2926364953-924364008-418108241-1000:ALLOWED/0x0/0x1e01ff ACL:S-1-1-0:ALLOWED/0x0/R # setcifsacl -a "ACL:S-1-22-2-1004:ALLOWED/0x0/R" /mnt/test/acltest this setacl will cause the following KASAN splat: [ 330.777927] BUG: KASAN: slab-out-of-bounds in send_set_info+0x4dd/0xc20 [cifs] [ 330.779696] Write of size 696 at addr ffff88010d5e2860 by task setcifsacl/1012 [ 330.781882] CPU: 1 PID: 1012 Comm: setcifsacl Not tainted 4.18.0-rc2+ #2 [ 330.783140] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014 [ 330.784395] Call Trace: [ 330.784789] dump_stack+0xc2/0x16b [ 330.786777] print_address_description+0x6a/0x270 [ 330.787520] kasan_report+0x258/0x380 [ 330.788845] memcpy+0x34/0x50 [ 330.789369] send_set_info+0x4dd/0xc20 [cifs] [ 330.799511] SMB2_set_acl+0x76/0xa0 [cifs] [ 330.801395] set_smb2_acl+0x7ac/0xf30 [cifs] [ 330.830888] cifs_xattr_set+0x963/0xe40 [cifs] [ 330.840367] __vfs_setxattr+0x84/0xb0 [ 330.842060] __vfs_setxattr_noperm+0xe6/0x370 [ 330.843848] vfs_setxattr+0xc2/0xd0 [ 330.845519] setxattr+0x258/0x320 [ 330.859211] path_setxattr+0x15b/0x1b0 [ 330.864392] __x64_sys_setxattr+0xc0/0x160 [ 330.866133] do_syscall_64+0x14e/0x4b0 [ 330.876631] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 330.878503] RIP: 0033:0x7ff2e507db0a [ 330.880151] Code: 48 8b 0d 89 93 2c 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 49 89 ca b8 bc 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 56 93 2c 00 f7 d8 64 89 01 48 [ 330.885358] RSP: 002b:00007ffdc4903c18 EFLAGS: 00000246 ORIG_RAX: 00000000000000bc [ 330.887733] RAX: ffffffffffffffda RBX: 000055d1170de140 RCX: 00007ff2e507db0a [ 330.890067] RDX: 000055d1170de7d0 RSI: 000055d115b39184 RDI: 00007ffdc4904818 [ 330.892410] RBP: 0000000000000001 R08: 0000000000000000 R09: 000055d1170de7e4 [ 330.894785] R10: 00000000000002b8 R11: 0000000000000246 R12: 0000000000000007 [ 330.897148] R13: 000055d1170de0c0 R14: 0000000000000008 R15: 000055d1170de550 [ 330.901057] Allocated by task 1012: [ 330.902888] kasan_kmalloc+0xa0/0xd0 [ 330.904714] kmem_cache_alloc+0xc8/0x1d0 [ 330.906615] mempool_alloc+0x11e/0x380 [ 330.908496] cifs_small_buf_get+0x35/0x60 [cifs] [ 330.910510] smb2_plain_req_init+0x4a/0xd60 [cifs] [ 330.912551] send_set_info+0x198/0xc20 [cifs] [ 330.914535] SMB2_set_acl+0x76/0xa0 [cifs] [ 330.916465] set_smb2_acl+0x7ac/0xf30 [cifs] [ 330.918453] cifs_xattr_set+0x963/0xe40 [cifs] [ 330.920426] __vfs_setxattr+0x84/0xb0 [ 330.922284] __vfs_setxattr_noperm+0xe6/0x370 [ 330.924213] vfs_setxattr+0xc2/0xd0 [ 330.926008] setxattr+0x258/0x320 [ 330.927762] path_setxattr+0x15b/0x1b0 [ 330.929592] __x64_sys_setxattr+0xc0/0x160 [ 330.931459] do_syscall_64+0x14e/0x4b0 [ 330.933314] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 330.936843] Freed by task 0: [ 330.938588] (stack is not available) [ 330.941886] The buggy address belongs to the object at ffff88010d5e2800 which belongs to the cache cifs_small_rq of size 448 [ 330.946362] The buggy address is located 96 bytes inside of 448-byte region [ffff88010d5e2800, ffff88010d5e29c0) [ 330.950722] The buggy address belongs to the page: [ 330.952789] page:ffffea0004357880 count:1 mapcount:0 mapping:ffff880108fdca80 index:0x0 compound_mapcount: 0 [ 330.955665] flags: 0x17ffffc0008100(slab|head) [ 330.957760] raw: 0017ffffc0008100 dead000000000100 dead000000000200 ffff880108fdca80 [ 330.960356] raw: 0000000000000000 0000000080100010 00000001ffffffff 0000000000000000 [ 330.963005] page dumped because: kasan: bad access detected [ 330.967039] Memory state around the buggy address: [ 330.969255] ffff88010d5e2880: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 330.971833] ffff88010d5e2900: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 330.974397] >ffff88010d5e2980: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc [ 330.976956] ^ [ 330.979226] ffff88010d5e2a00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 330.981755] ffff88010d5e2a80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 330.984225] ================================================================== Fix this by allocating a regular CIFS buffer in smb2_plain_req_init() if the request command is SMB2_SET_INFO. Reported-by: Jianhong Yin Fixes: 366ed846df60 ("cifs: Use smb 2 - 3 and cifsacl mount options setacl function") CC: Stable Signed-off-by: Stefano Brivio Reviewed-and-tested-by: Aurelien Aptel Signed-off-by: Steve French Signed-off-by: Greg Kroah-Hartman --- fs/cifs/smb2pdu.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) --- a/fs/cifs/smb2pdu.c +++ b/fs/cifs/smb2pdu.c @@ -338,7 +338,10 @@ smb2_plain_req_init(__le16 smb2_command, return rc; /* BB eventually switch this to SMB2 specific small buf size */ - *request_buf = cifs_small_buf_get(); + if (smb2_command == SMB2_SET_INFO) + *request_buf = cifs_buf_get(); + else + *request_buf = cifs_small_buf_get(); if (*request_buf == NULL) { /* BB should we add a retry in here if not a writepage? */ return -ENOMEM; @@ -3168,7 +3171,7 @@ send_set_info(const unsigned int xid, st } rc = SendReceive2(xid, ses, iov, num, &resp_buftype, flags, &rsp_iov); - cifs_small_buf_release(req); + cifs_buf_release(req); rsp = (struct smb2_set_info_rsp *)rsp_iov.iov_base; if (rc != 0)