From ef399469d9ceb9f2171cdd79863f9434b9fa3edc Mon Sep 17 00:00:00 2001 From: Dan Carpenter Date: Tue, 30 Nov 2021 15:50:47 +0300 Subject: [PATCH 1/3] ksmbd: fix error code in ndr_read_int32() This is a failure path and it should return -EINVAL instead of success. Otherwise it could result in the caller using uninitialized memory. Fixes: 303fff2b8c77 ("ksmbd: add validation for ndr read/write functions") Cc: stable@vger.kernel.org # v5.15 Acked-by: Namjae Jeon Signed-off-by: Dan Carpenter Signed-off-by: Steve French --- fs/ksmbd/ndr.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/ksmbd/ndr.c b/fs/ksmbd/ndr.c index 8317f7ca402b4f..5052be9261d91e 100644 --- a/fs/ksmbd/ndr.c +++ b/fs/ksmbd/ndr.c @@ -148,7 +148,7 @@ static int ndr_read_int16(struct ndr *n, __u16 *value) static int ndr_read_int32(struct ndr *n, __u32 *value) { if (n->offset + sizeof(__u32) > n->length) - return 0; + return -EINVAL; if (value) *value = le32_to_cpu(*(__le32 *)ndr_get_field(n)); From f2e78affc48dee29b989c1d9b0d89b503dcd1204 Mon Sep 17 00:00:00 2001 From: Namjae Jeon Date: Wed, 1 Dec 2021 10:12:39 +0900 Subject: [PATCH 2/3] ksmbd: fix uninitialized symbol 'pntsd_size' No check for if "rc" is an error code for build_sec_desc(). This can cause problems with using uninitialized pntsd_size. Fixes: e2f34481b24d ("cifsd: add server-side procedures for SMB3") Cc: stable@vger.kernel.org # v5.15 Reported-by: Dan Carpenter Signed-off-by: Namjae Jeon Signed-off-by: Steve French --- fs/ksmbd/smb2pdu.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/fs/ksmbd/smb2pdu.c b/fs/ksmbd/smb2pdu.c index 49c9da37315c83..125590d5e94024 100644 --- a/fs/ksmbd/smb2pdu.c +++ b/fs/ksmbd/smb2pdu.c @@ -2962,6 +2962,10 @@ int smb2_open(struct ksmbd_work *work) &pntsd_size, &fattr); posix_acl_release(fattr.cf_acls); posix_acl_release(fattr.cf_dacls); + if (rc) { + kfree(pntsd); + goto err_out; + } rc = ksmbd_vfs_set_sd_xattr(conn, user_ns, From 83912d6d55be10d65b5268d1871168b9ebe1ec4b Mon Sep 17 00:00:00 2001 From: Marcos Del Sol Vives Date: Thu, 16 Dec 2021 11:37:22 +0100 Subject: [PATCH 3/3] ksmbd: disable SMB2_GLOBAL_CAP_ENCRYPTION for SMB 3.1.1 According to the official Microsoft MS-SMB2 document section 3.3.5.4, this flag should be used only for 3.0 and 3.0.2 dialects. Setting it for 3.1.1 is a violation of the specification. This causes my Windows 10 client to detect an anomaly in the negotiation, and disable encryption entirely despite being explicitly enabled in ksmbd, causing all data transfers to go in plain text. Fixes: e2f34481b24d ("cifsd: add server-side procedures for SMB3") Cc: stable@vger.kernel.org # v5.15 Acked-by: Namjae Jeon Signed-off-by: Marcos Del Sol Vives Signed-off-by: Steve French --- fs/ksmbd/smb2ops.c | 3 --- fs/ksmbd/smb2pdu.c | 25 +++++++++++++++++++++---- 2 files changed, 21 insertions(+), 7 deletions(-) diff --git a/fs/ksmbd/smb2ops.c b/fs/ksmbd/smb2ops.c index 0a5d8450e835fa..02a44d28bdafc2 100644 --- a/fs/ksmbd/smb2ops.c +++ b/fs/ksmbd/smb2ops.c @@ -271,9 +271,6 @@ int init_smb3_11_server(struct ksmbd_conn *conn) if (server_conf.flags & KSMBD_GLOBAL_FLAG_SMB2_LEASES) conn->vals->capabilities |= SMB2_GLOBAL_CAP_LEASING; - if (conn->cipher_type) - conn->vals->capabilities |= SMB2_GLOBAL_CAP_ENCRYPTION; - if (server_conf.flags & KSMBD_GLOBAL_FLAG_SMB3_MULTICHANNEL) conn->vals->capabilities |= SMB2_GLOBAL_CAP_MULTI_CHANNEL; diff --git a/fs/ksmbd/smb2pdu.c b/fs/ksmbd/smb2pdu.c index 125590d5e94024..b8b3a4c28b749a 100644 --- a/fs/ksmbd/smb2pdu.c +++ b/fs/ksmbd/smb2pdu.c @@ -915,6 +915,25 @@ static void decode_encrypt_ctxt(struct ksmbd_conn *conn, } } +/** + * smb3_encryption_negotiated() - checks if server and client agreed on enabling encryption + * @conn: smb connection + * + * Return: true if connection should be encrypted, else false + */ +static bool smb3_encryption_negotiated(struct ksmbd_conn *conn) +{ + if (!conn->ops->generate_encryptionkey) + return false; + + /* + * SMB 3.0 and 3.0.2 dialects use the SMB2_GLOBAL_CAP_ENCRYPTION flag. + * SMB 3.1.1 uses the cipher_type field. + */ + return (conn->vals->capabilities & SMB2_GLOBAL_CAP_ENCRYPTION) || + conn->cipher_type; +} + static void decode_compress_ctxt(struct ksmbd_conn *conn, struct smb2_compression_capabilities_context *pneg_ctxt) { @@ -1469,8 +1488,7 @@ static int ntlm_authenticate(struct ksmbd_work *work) (req->SecurityMode & SMB2_NEGOTIATE_SIGNING_REQUIRED)) sess->sign = true; - if (conn->vals->capabilities & SMB2_GLOBAL_CAP_ENCRYPTION && - conn->ops->generate_encryptionkey && + if (smb3_encryption_negotiated(conn) && !(req->Flags & SMB2_SESSION_REQ_FLAG_BINDING)) { rc = conn->ops->generate_encryptionkey(sess); if (rc) { @@ -1559,8 +1577,7 @@ static int krb5_authenticate(struct ksmbd_work *work) (req->SecurityMode & SMB2_NEGOTIATE_SIGNING_REQUIRED)) sess->sign = true; - if ((conn->vals->capabilities & SMB2_GLOBAL_CAP_ENCRYPTION) && - conn->ops->generate_encryptionkey) { + if (smb3_encryption_negotiated(conn)) { retval = conn->ops->generate_encryptionkey(sess); if (retval) { ksmbd_debug(SMB,