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| author | Marios Makassikis <mmakassikis@freebox.fr> | 2023-01-11 17:39:02 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-02-01 08:27:24 +0100 |
| commit | 87a7f38a9058df1743963645c8afa2b6a58c6591 (patch) | |
| tree | 08e9fde34f9f4fe4cb30b56f64aa30c1e08956f9 /fs | |
| parent | 4210c3555db4b38bade92331b153e583261f05f9 (diff) | |
| download | linux-87a7f38a9058df1743963645c8afa2b6a58c6591.tar.gz linux-87a7f38a9058df1743963645c8afa2b6a58c6591.tar.bz2 linux-87a7f38a9058df1743963645c8afa2b6a58c6591.zip | |
ksmbd: do not sign response to session request for guest login
commit 5fde3c21cf33830eda7bfd006dc7f4bf07ec9fe6 upstream.
If ksmbd.mountd is configured to assign unknown users to the guest account
("map to guest = bad user" in the config), ksmbd signs the response.
This is wrong according to MS-SMB2 3.3.5.5.3:
12. If the SMB2_SESSION_FLAG_IS_GUEST bit is not set in the SessionFlags
field, and Session.IsAnonymous is FALSE, the server MUST sign the
final session setup response before sending it to the client, as
follows:
[...]
This fixes libsmb2 based applications failing to establish a session
("Wrong signature in received").
Fixes: e2f34481b24d ("cifsd: add server-side procedures for SMB3")
Cc: stable@vger.kernel.org
Signed-off-by: Marios Makassikis <mmakassikis@freebox.fr>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/ksmbd/smb2pdu.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/fs/ksmbd/smb2pdu.c b/fs/ksmbd/smb2pdu.c index 65c85ca71ebe..ac029dfd23ab 100644 --- a/fs/ksmbd/smb2pdu.c +++ b/fs/ksmbd/smb2pdu.c @@ -8613,6 +8613,7 @@ int smb3_decrypt_req(struct ksmbd_work *work) bool smb3_11_final_sess_setup_resp(struct ksmbd_work *work) { struct ksmbd_conn *conn = work->conn; + struct ksmbd_session *sess = work->sess; struct smb2_hdr *rsp = work->response_buf; if (conn->dialect < SMB30_PROT_ID) @@ -8622,6 +8623,7 @@ bool smb3_11_final_sess_setup_resp(struct ksmbd_work *work) rsp = ksmbd_resp_buf_next(work); if (le16_to_cpu(rsp->Command) == SMB2_SESSION_SETUP_HE && + sess->user && !user_guest(sess->user) && rsp->Status == STATUS_SUCCESS) return true; return false; |