From d9b942013730c38ac83564d6669c6d0ecf6d754d Mon Sep 17 00:00:00 2001 From: Steve French Date: Tue, 12 Apr 2011 01:24:57 +0000 Subject: [PATCH] [CIFS] Warn on requesting default security (ntlm) on mount Warn once if default security (ntlm) requested. We will update the default to the stronger security mechanism (ntlmv2) in 2.6.41. Kerberos is also stronger than ntlm, but more servers support ntlmv2 and ntlmv2 does not require an upcall, so ntlmv2 is a better default. Reviewed-by: Jeff Layton CC: Suresh Jayaraman Reviewed-by: Shirish Pargaonkar Signed-off-by: Steve French --- fs/cifs/connect.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c index 8cf4a63a36d5..db9d55b507d0 100644 --- a/fs/cifs/connect.c +++ b/fs/cifs/connect.c @@ -1854,6 +1854,8 @@ cifs_put_smb_ses(struct cifsSesInfo *ses) cifs_put_tcp_session(server); } +static bool warned_on_ntlm; /* globals init to false automatically */ + static struct cifsSesInfo * cifs_get_smb_ses(struct TCP_Server_Info *server, struct smb_vol *volume_info) { @@ -1928,6 +1930,15 @@ cifs_get_smb_ses(struct TCP_Server_Info *server, struct smb_vol *volume_info) } ses->cred_uid = volume_info->cred_uid; ses->linux_uid = volume_info->linux_uid; + + /* ntlmv2 is much stronger than ntlm security, and has been broadly + supported for many years, time to update default security mechanism */ + if ((volume_info->secFlg == 0) && warned_on_ntlm == false) { + warned_on_ntlm = true; + cERROR(1, "default security mechanism requested. The default " + "security mechanism will be upgraded from ntlm to " + "ntlmv2 in kernel release 2.6.41"); + } ses->overrideSecFlg = volume_info->secFlg; mutex_lock(&ses->session_mutex); -- 2.30.2