From: Pavel Shilovsky <pshilov@microsoft.com>
Date: Fri, 8 Sep 2017 13:06:00 +0000 (+0200)
Subject: CIFS: Fix maximum SMB2 header size
X-Git-Tag: Ubuntu-4.10.0-36.40~12
X-Git-Url: https://git.proxmox.com/?p=mirror_ubuntu-zesty-kernel.git;a=commitdiff_plain;h=d523d85ea2c94c904912dee90a71f22f479e5a62

CIFS: Fix maximum SMB2 header size

BugLink: http://bugs.launchpad.net/bugs/1713884

Currently the maximum size of SMB2/3 header is set incorrectly which
leads to hanging of directory listing operations on encrypted SMB3
connections. Fix this by setting the maximum size to 170 bytes that
is calculated as RFC1002 length field size (4) + transform header
size (52) + SMB2 header size (64) + create response size (56).

Cc: <stable@vger.kernel.org>
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Acked-by: Sachin Prabhu <sprabhu@redhat.com>
(cherry picked from commit 9e37b1784f2be9397a903307574ee565bbadfd75)
Signed-off-by: Joseph Salisbury <joseph.salisbury@canonical.com>
Acked-by: Stefan Bader <stefan.bader@canonical.com>
Acked-by: Colin King <colin.king@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
---

diff --git a/fs/cifs/smb2pdu.h b/fs/cifs/smb2pdu.h
index c03b252501a1..9a8f8feb79bd 100644
--- a/fs/cifs/smb2pdu.h
+++ b/fs/cifs/smb2pdu.h
@@ -84,8 +84,8 @@
 
 #define NUMBER_OF_SMB2_COMMANDS	0x0013
 
-/* BB FIXME - analyze following length BB */
-#define MAX_SMB2_HDR_SIZE 0x78 /* 4 len + 64 hdr + (2*24 wct) + 2 bct + 2 pad */
+/* 4 len + 52 transform hdr + 64 hdr + 56 create rsp */
+#define MAX_SMB2_HDR_SIZE 0x00b0
 
 #define SMB2_PROTO_NUMBER cpu_to_le32(0x424d53fe)
 #define SMB2_TRANSFORM_PROTO_NUM cpu_to_le32(0x424d53fd)