From: Steve French <stfrench@microsoft.com>
Date: Sun, 1 Apr 2018 20:15:55 -0500
Subject: [PATCH] cifs: Add minor debug message during negprot
Git-commit: 07108d0e7c7fbbf9c6d76c0af2f1813e4f3f0800
Patch-mainline: v4.17-rc1
References: bsc#1144333
Check for unknown security mode flags during negotiate protocol
if debugging enabled.
Signed-off-by: Steve French <smfrench@gmail.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Acked-by: Aurelien Aptel <aaptel@suse.com>
---
fs/cifs/smb2pdu.c | 4 +++-
fs/cifs/smb2pdu.h | 2 ++
2 files changed, 5 insertions(+), 1 deletion(-)
diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
index 0e04b577758d..f7741cee2a4c 100644
--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -584,8 +584,10 @@ SMB2_negotiate(const unsigned int xid, struct cifs_ses *ses)
SMB2_MAX_BUFFER_SIZE);
server->max_read = le32_to_cpu(rsp->MaxReadSize);
server->max_write = le32_to_cpu(rsp->MaxWriteSize);
- /* BB Do we need to validate the SecurityMode? */
server->sec_mode = le16_to_cpu(rsp->SecurityMode);
+ if ((server->sec_mode & SMB2_SEC_MODE_FLAGS_ALL) != server->sec_mode)
+ cifs_dbg(FYI, "Server returned unexpected security mode 0x%x\n",
+ server->sec_mode);
server->capabilities = le32_to_cpu(rsp->Capabilities);
/* Internal types */
server->capabilities |= SMB2_NT_FIND | SMB2_LARGE_FILES;
diff --git a/fs/cifs/smb2pdu.h b/fs/cifs/smb2pdu.h
index 8b901c69a65a..253e2c7c952f 100644
--- a/fs/cifs/smb2pdu.h
+++ b/fs/cifs/smb2pdu.h
@@ -249,6 +249,8 @@ struct smb2_negotiate_req {
/* SecurityMode flags */
#define SMB2_NEGOTIATE_SIGNING_ENABLED 0x0001
#define SMB2_NEGOTIATE_SIGNING_REQUIRED 0x0002
+#define SMB2_SEC_MODE_FLAGS_ALL 0x0003
+
/* Capabilities flags */
#define SMB2_GLOBAL_CAP_DFS 0x00000001
#define SMB2_GLOBAL_CAP_LEASING 0x00000002 /* Resp only New to SMB2.1 */
--
2.16.4