From f1d84943289e9f982077e37d042895f56e18ecc1 Mon Sep 17 00:00:00 2001 From: Stefan Metzmacher Date: Wed, 1 Feb 2023 16:21:41 +0100 Subject: cifs: don't try to use rdma offload on encrypted connections commit 3891f6c7655a39065e44980f51ba46bb32be3133 upstream. The aim of using encryption on a connection is to keep the data confidential, so we must not use plaintext rdma offload for that data! It seems that current windows servers and ksmbd would allow this, but that's no reason to expose the users data in plaintext! And servers hopefully reject this in future. Note modern windows servers support signed or encrypted offload, see MS-SMB2 2.2.3.1.6 SMB2_RDMA_TRANSFORM_CAPABILITIES, but we don't support that yet. Signed-off-by: Stefan Metzmacher Cc: Steve French Cc: Tom Talpey Cc: Long Li Cc: Namjae Jeon Cc: David Howells Cc: linux-cifs@vger.kernel.org Cc: stable@vger.kernel.org Signed-off-by: Steve French Signed-off-by: Greg Kroah-Hartman --- fs/cifs/smb2pdu.c | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'fs/cifs') diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c index b68f43edf72a..23926f754d2a 100644 --- a/fs/cifs/smb2pdu.c +++ b/fs/cifs/smb2pdu.c @@ -4081,6 +4081,10 @@ static inline bool smb3_use_rdma_offload(struct cifs_io_parms *io_parms) if (server->sign) return false; + /* we don't support encrypted offload yet */ + if (smb3_encryption_required(tcon)) + return false; + /* offload also has its overhead, so only do it if desired */ if (io_parms->length < server->smbd_conn->rdma_readwrite_threshold) return false; -- cgit v1.2.3