Patch "cifs: Fix autonegotiate security settings mismatch" has been added to the 3.18-stable tree

This is a note to let you know that I've just added the patch titled

cifs: Fix autonegotiate security settings mismatch

to the 3.18-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
cifs-fix-autonegotiate-security-settings-mismatch.patch
and it can be found in the queue-3.18 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Daniel N Pettersson <[email protected]>
Date: Thu, 11 Jan 2018 16:00:12 +0100
Subject: cifs: Fix autonegotiate security settings mismatch

From: Daniel N Pettersson <[email protected]>

commit 9aca7e454415f7878b28524e76bebe1170911a88 upstream.

Autonegotiation gives a security settings mismatch error if the SMB server selects an SMBv3 dialect that isn't SMB3.02. The exact error is "protocol revalidation - security settings mismatch".
This can be tested using Samba v4.2 or by setting the global Samba setting max protocol = SMB3_00.

The check that fails in smb3_validate_negotiate is the dialect verification of the negotiate info response. This is because it tries to verify against the protocol_id in the global smbdefault_values. The protocol_id in smbdefault_values is SMB3.02.
In SMB2_negotiate the protocol_id in smbdefault_values isn't updated, it is global so it probably shouldn't be, but server->dialect is.

This patch changes the check in smb3_validate_negotiate to use server->dialect instead of server->vals->protocol_id. The patch works with autonegotiate and when using a specific version in the vers mount option.

---
 fs/cifs/smb2pdu.c |    3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

@@ -507,8 +507,7 @@ int smb3_validate_negotiate(const unsign
 	}
 
 	/* check validate negotiate info response matches what we got earlier */
-	if (pneg_rsp->Dialect !=
-			cpu_to_le16(tcon->ses->server->vals->protocol_id))
+	if (pneg_rsp->Dialect != cpu_to_le16(tcon->ses->server->dialect))
 		goto vneg_out;
 
 	if (pneg_rsp->SecurityMode != cpu_to_le16(tcon->ses->server->sec_mode))

Patches currently in stable-queue which might be from [email protected] are

queue-3.18/cifs-fix-autonegotiate-security-settings-mismatch.patch