| Message ID | cd26594054b0c291e01b1da20f974245d3f494c3.1675264648.git.metze@samba.org |
|---|---|
| State | New |
| Headers | show |
| Series | avoid plaintext rdma offload if encryption is required | expand |
diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c index 6a4d621241dd..c5cb2639b3f1 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;
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 <metze@samba.org> Cc: Steve French <smfrench@gmail.com> Cc: Tom Talpey <tom@talpey.com> Cc: Long Li <longli@microsoft.com> Cc: Namjae Jeon <linkinjeon@kernel.org> Cc: David Howells <dhowells@redhat.com> Cc: linux-cifs@vger.kernel.org Cc: stable@vger.kernel.org --- fs/cifs/smb2pdu.c | 4 ++++ 1 file changed, 4 insertions(+)