[ Upstream commit 92e470163d96df8db6c4fa0f484e4a229edb903d ]
If client send invalid mech token in session setup request, ksmbd validate and make the error if it is invalid.
Cc: stable@vger.kernel.org Reported-by: zdi-disclosures@trendmicro.com # ZDI-CAN-22890 Signed-off-by: Namjae Jeon linkinjeon@kernel.org Signed-off-by: Steve French stfrench@microsoft.com --- fs/ksmbd/asn1.c | 5 +++++ fs/ksmbd/connection.h | 1 + fs/ksmbd/smb2pdu.c | 22 +++++++++++++++++----- 3 files changed, 23 insertions(+), 5 deletions(-)
diff --git a/fs/ksmbd/asn1.c b/fs/ksmbd/asn1.c index 4a4b2b03ff33..b931a99ab9c8 100644 --- a/fs/ksmbd/asn1.c +++ b/fs/ksmbd/asn1.c @@ -214,10 +214,15 @@ static int ksmbd_neg_token_alloc(void *context, size_t hdrlen, { struct ksmbd_conn *conn = context;
+ if (!vlen) + return -EINVAL; + conn->mechToken = kmemdup_nul(value, vlen, GFP_KERNEL); if (!conn->mechToken) return -ENOMEM;
+ conn->mechTokenLen = (unsigned int)vlen; + return 0; }
diff --git a/fs/ksmbd/connection.h b/fs/ksmbd/connection.h index 3c005246a32e..342f935f5770 100644 --- a/fs/ksmbd/connection.h +++ b/fs/ksmbd/connection.h @@ -88,6 +88,7 @@ struct ksmbd_conn { __u16 dialect;
char *mechToken; + unsigned int mechTokenLen;
struct ksmbd_conn_ops *conn_ops;
diff --git a/fs/ksmbd/smb2pdu.c b/fs/ksmbd/smb2pdu.c index 795d3554abe2..7e8f1c89124f 100644 --- a/fs/ksmbd/smb2pdu.c +++ b/fs/ksmbd/smb2pdu.c @@ -1414,7 +1414,10 @@ static struct ksmbd_user *session_user(struct ksmbd_conn *conn, char *name; unsigned int name_off, name_len, secbuf_len;
- secbuf_len = le16_to_cpu(req->SecurityBufferLength); + if (conn->use_spnego && conn->mechToken) + secbuf_len = conn->mechTokenLen; + else + secbuf_len = le16_to_cpu(req->SecurityBufferLength); if (secbuf_len < sizeof(struct authenticate_message)) { ksmbd_debug(SMB, "blob len %d too small\n", secbuf_len); return NULL; @@ -1505,7 +1508,10 @@ static int ntlm_authenticate(struct ksmbd_work *work, struct authenticate_message *authblob;
authblob = user_authblob(conn, req); - sz = le16_to_cpu(req->SecurityBufferLength); + if (conn->use_spnego && conn->mechToken) + sz = conn->mechTokenLen; + else + sz = le16_to_cpu(req->SecurityBufferLength); rc = ksmbd_decode_ntlmssp_auth_blob(authblob, sz, conn, sess); if (rc) { set_user_flag(sess->user, KSMBD_USER_FLAG_BAD_PASSWORD); @@ -1778,8 +1784,7 @@ int smb2_sess_setup(struct ksmbd_work *work)
negblob_off = le16_to_cpu(req->SecurityBufferOffset); negblob_len = le16_to_cpu(req->SecurityBufferLength); - if (negblob_off < offsetof(struct smb2_sess_setup_req, Buffer) || - negblob_len < offsetof(struct negotiate_message, NegotiateFlags)) { + if (negblob_off < offsetof(struct smb2_sess_setup_req, Buffer)) { rc = -EINVAL; goto out_err; } @@ -1788,8 +1793,15 @@ int smb2_sess_setup(struct ksmbd_work *work) negblob_off);
if (decode_negotiation_token(conn, negblob, negblob_len) == 0) { - if (conn->mechToken) + if (conn->mechToken) { negblob = (struct negotiate_message *)conn->mechToken; + negblob_len = conn->mechTokenLen; + } + } + + if (negblob_len < offsetof(struct negotiate_message, NegotiateFlags)) { + rc = -EINVAL; + goto out_err; }
if (server_conf.auth_mechs & conn->auth_mechs) {