smb: client: Fix match_session bug preventing session reuse

commit 605b249ea96770ac4fac4b8510a99e0f8442be5e upstream.

Fix a bug in match_session() that can causes the session to not be
reused in some cases.

Reproduction steps:

mount.cifs //server/share /mnt/a -o credentials=creds
mount.cifs //server/share /mnt/b -o credentials=creds,sec=ntlmssp
cat /proc/fs/cifs/DebugData | grep SessionId | wc -l

mount.cifs //server/share /mnt/b -o credentials=creds,sec=ntlmssp
mount.cifs //server/share /mnt/a -o credentials=creds
cat /proc/fs/cifs/DebugData | grep SessionId | wc -l

Cc: stable@vger.kernel.org
Reviewed-by: Enzo Matsumiya <ematsumiya@suse.de>
Signed-off-by: Henrique Carvalho <henrique.carvalho@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index 1cbfb74c53804a1d4bdbceaee0eee34b0f66d22b..96788385e1e735c33c411cb3ead4c227b19b1eb5 100644 (file)
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -1582,9 +1582,8 @@ out_err:
 
 static int match_session(struct cifs_ses *ses, struct smb3_fs_context *ctx)
 {
-       if (ctx->sectype != Unspecified &&
-           ctx->sectype != ses->sectype)
-               return 0;
+       struct TCP_Server_Info *server = ses->server;
+       enum securityEnum ctx_sec, ses_sec;
 
        /*
         * If an existing session is limited to less channels than
@@ -1597,11 +1596,19 @@ static int match_session(struct cifs_ses *ses, struct smb3_fs_context *ctx)
        }
        spin_unlock(&ses->chan_lock);
 
-       switch (ses->sectype) {
+       ctx_sec = server->ops->select_sectype(server, ctx->sectype);
+       ses_sec = server->ops->select_sectype(server, ses->sectype);
+
+       if (ctx_sec != ses_sec)
+               return 0;
+
+       switch (ctx_sec) {
        case Kerberos:
                if (!uid_eq(ctx->cred_uid, ses->cred_uid))
                        return 0;
                break;
+       case NTLMv2:
+       case RawNTLMSSP:
        default:
                /* NULL username means anonymous session */
                if (ses->user_name == NULL) {