Merge: smb: client: fix UAF in async decryption

MR: https://gitlab.com/redhat/centos-stream/src/kernel/centos-stream-9/-/merge_requests/5690

JIRA: https://issues.redhat.com/browse/RHEL-63909

CVE: CVE-2024-50047

Signed-off-by: Paulo Alcantara <paalcant@redhat.com>

Approved-by: Scott Mayhew <smayhew@redhat.com>
Approved-by: Benjamin Coddington <bcodding@redhat.com>
Approved-by: Jay Shin <jaeshin@redhat.com>
Approved-by: CKI KWF Bot <cki-ci-bot+kwf-gitlab-com@redhat.com>

Merged-by: Rado Vrbovsky <rvrbovsk@redhat.com>

Author: emmil

fs/smb/client/smb2ops.c

@@ -4226,7 +4226,7 @@ smb2_get_enc_key(struct TCP_Server_Info *server, __u64 ses_id, int enc, u8 *key)
  */
 static int
 crypt_message(struct TCP_Server_Info *server, int num_rqst,
-	      struct smb_rqst *rqst, int enc)
+	      struct smb_rqst *rqst, int enc, struct crypto_aead *tfm)
 {
 	struct smb2_transform_hdr *tr_hdr =
 		(struct smb2_transform_hdr *)rqst[0].rq_iov[0].iov_base;
@@ -4237,8 +4237,6 @@ crypt_message(struct TCP_Server_Info *server, int num_rqst,
 	u8 key[SMB3_ENC_DEC_KEY_SIZE];
 	struct aead_request *req;
 	u8 *iv;
-	DECLARE_CRYPTO_WAIT(wait);
-	struct crypto_aead *tfm;
 	unsigned int crypt_len = le32_to_cpu(tr_hdr->OriginalMessageSize);
 	void *creq;
 
@@ -4249,14 +4247,6 @@ crypt_message(struct TCP_Server_Info *server, int num_rqst,
 		return rc;
 	}
 
-	rc = smb3_crypto_aead_allocate(server);
-	if (rc) {
-		cifs_server_dbg(VFS, "%s: crypto alloc failed\n", __func__);
-		return rc;
-	}
-
-	tfm = enc ? server->secmech.enc : server->secmech.dec;
-
 	if ((server->cipher_type == SMB2_ENCRYPTION_AES256_CCM) ||
 		(server->cipher_type == SMB2_ENCRYPTION_AES256_GCM))
 		rc = crypto_aead_setkey(tfm, key, SMB3_GCM256_CRYPTKEY_SIZE);
@@ -4295,11 +4285,7 @@ crypt_message(struct TCP_Server_Info *server, int num_rqst,
 	aead_request_set_crypt(req, sg, sg, crypt_len, iv);
 	aead_request_set_ad(req, assoc_data_len);
 
-	aead_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG,
-				  crypto_req_done, &wait);
-
-	rc = crypto_wait_req(enc ? crypto_aead_encrypt(req)
-				: crypto_aead_decrypt(req), &wait);
+	rc = enc ? crypto_aead_encrypt(req) : crypto_aead_decrypt(req);
 
 	if (!rc && enc)
 		memcpy(&tr_hdr->Signature, sign, SMB2_SIGNATURE_SIZE);
@@ -4389,7 +4375,7 @@ smb3_init_transform_rq(struct TCP_Server_Info *server, int num_rqst,
 	/* fill the 1st iov with a transform header */
 	fill_transform_hdr(tr_hdr, orig_len, old_rq, server->cipher_type);
 
-	rc = crypt_message(server, num_rqst, new_rq, 1);
+	rc = crypt_message(server, num_rqst, new_rq, 1, server->secmech.enc);
 	cifs_dbg(FYI, "Encrypt message returned %d\n", rc);
 	if (rc)
 		goto err_free;
@@ -4415,8 +4401,9 @@ decrypt_raw_data(struct TCP_Server_Info *server, char *buf,
 		 unsigned int npages, unsigned int page_data_size,
 		 bool is_offloaded)
 {
-	struct kvec iov[2];
+	struct crypto_aead *tfm;
 	struct smb_rqst rqst = {NULL};
+	struct kvec iov[2];
 	int rc;
 
 	iov[0].iov_base = buf;
@@ -4431,9 +4418,31 @@ decrypt_raw_data(struct TCP_Server_Info *server, char *buf,
 	rqst.rq_pagesz = PAGE_SIZE;
 	rqst.rq_tailsz = (page_data_size % PAGE_SIZE) ? : PAGE_SIZE;
 
-	rc = crypt_message(server, 1, &rqst, 0);
+	if (is_offloaded) {
+		if ((server->cipher_type == SMB2_ENCRYPTION_AES128_GCM) ||
+		    (server->cipher_type == SMB2_ENCRYPTION_AES256_GCM))
+			tfm = crypto_alloc_aead("gcm(aes)", 0, 0);
+		else
+			tfm = crypto_alloc_aead("ccm(aes)", 0, 0);
+		if (IS_ERR(tfm)) {
+			rc = PTR_ERR(tfm);
+			cifs_server_dbg(VFS, "%s: Failed alloc decrypt TFM, rc=%d\n", __func__, rc);
+
+			return rc;
+		}
+	} else {
+		if (unlikely(!server->secmech.dec))
+			return -EIO;
+
+		tfm = server->secmech.dec;
+	}
+
+	rc = crypt_message(server, 1, &rqst, 0, tfm);
 	cifs_dbg(FYI, "Decrypt message returned %d\n", rc);
 
+	if (is_offloaded)
+		crypto_free_aead(tfm);
+
 	if (rc)
 		return rc;
 

fs/smb/client/smb2pdu.c

@@ -1228,7 +1228,9 @@ SMB2_negotiate(const unsigned int xid,
 	 * SMB3.0 supports only 1 cipher and doesn't have a encryption neg context
 	 * Set the cipher type manually.
 	 */
-	if (server->dialect == SMB30_PROT_ID && (server->capabilities & SMB2_GLOBAL_CAP_ENCRYPTION))
+	if ((server->dialect == SMB30_PROT_ID ||
+	     server->dialect == SMB302_PROT_ID) &&
+	    (server->capabilities & SMB2_GLOBAL_CAP_ENCRYPTION))
 		server->cipher_type = SMB2_ENCRYPTION_AES128_CCM;
 
 	security_blob = smb2_get_data_area_len(&blob_offset, &blob_length,
@@ -1263,6 +1265,12 @@ SMB2_negotiate(const unsigned int xid,
 		else
 			cifs_server_dbg(VFS, "Missing expected negotiate contexts\n");
 	}
+
+	if (server->cipher_type && !rc) {
+		rc = smb3_crypto_aead_allocate(server);
+		if (rc)
+			cifs_server_dbg(VFS, "%s: crypto alloc failed, rc=%d\n", __func__, rc);
+	}
 neg_exit:
 	free_rsp_buf(resp_buftype, rsp);
 	return rc;