From patchwork Sun Sep 18 03:36:19 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Enzo Matsumiya X-Patchwork-Id: 1678958 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@legolas.ozlabs.org Authentication-Results: legolas.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=2620:137:e000::1:20; helo=out1.vger.email; envelope-from=linux-cifs-owner@vger.kernel.org; receiver=) Authentication-Results: legolas.ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=suse.de header.i=@suse.de header.a=rsa-sha256 header.s=susede2_rsa header.b=M95fPibR; dkim=pass header.d=suse.de header.i=@suse.de header.a=ed25519-sha256 header.s=susede2_ed25519 header.b=NQ+UiVxa; dkim-atps=neutral Received: from out1.vger.email (out1.vger.email [IPv6:2620:137:e000::1:20]) by legolas.ozlabs.org (Postfix) with ESMTP id 4MVYQ23vjhz1yp7 for ; Sun, 18 Sep 2022 13:36:42 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229583AbiIRDgb (ORCPT ); Sat, 17 Sep 2022 23:36:31 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52018 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229471AbiIRDg3 (ORCPT ); Sat, 17 Sep 2022 23:36:29 -0400 Received: from smtp-out1.suse.de (smtp-out1.suse.de [195.135.220.28]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8980F237E6 for ; Sat, 17 Sep 2022 20:36:28 -0700 (PDT) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id AA62C228A2; Sun, 18 Sep 2022 03:36:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1663472186; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=DkKHAe19o/Nf3+FBFsHAp334rshYF99cYJnsuv30mTQ=; b=M95fPibRwBKvWCg0VupRLIM1tahQbvLlfj5RsN3nmssO7E+g2Igj34DilblyEvpeEmfmnE aN3Qhp8HLnHOkWUffG1libiaDwleAwDQ5sq3A5bHbExIpQo6CtYyLmWPys2NXgr3iFwfOS w95I7KwYjREhzYNBI36wp+1ezXFM/O0= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1663472186; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=DkKHAe19o/Nf3+FBFsHAp334rshYF99cYJnsuv30mTQ=; b=NQ+UiVxaDFZVS6xlwkaEe8VXSnkVMNjk3X/M3lI+rXfOOnnmQ6e+pLHCHHNPPlj45ibC1B PqYJ/HMb/ds4WoDg== Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id 2D8C213A49; Sun, 18 Sep 2022 03:36:25 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id ZmWiODmSJmMqYwAAMHmgww (envelope-from ); Sun, 18 Sep 2022 03:36:25 +0000 From: Enzo Matsumiya To: linux-cifs@vger.kernel.org Cc: smfrench@gmail.com, pc@cjr.nz, ronniesahlberg@gmail.com, nspmangalore@gmail.com Subject: [PATCH v2] cifs: replace kfree() with kfree_sensitive() for sensitive data Date: Sun, 18 Sep 2022 00:36:19 -0300 Message-Id: <20220918033619.16522-1-ematsumiya@suse.de> X-Mailer: git-send-email 2.35.3 MIME-Version: 1.0 X-Spam-Status: No, score=-4.4 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_MED,SPF_HELO_NONE, SPF_PASS autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-cifs@vger.kernel.org This patch is mosltly a s/kfree/kfree_sensitive/ for sensitive material that could still be left in memory. Signed-off-by: Enzo Matsumiya --- v2: remove unnecessary NULL checks before kfree_sensitive() fs/cifs/cifsencrypt.c | 12 ++++++------ fs/cifs/connect.c | 6 +++--- fs/cifs/fs_context.c | 12 ++++++++++-- fs/cifs/misc.c | 2 +- fs/cifs/sess.c | 24 +++++++++++++++--------- fs/cifs/smb2ops.c | 6 +++--- fs/cifs/smb2pdu.c | 22 +++++++++++++++++----- 7 files changed, 55 insertions(+), 29 deletions(-) diff --git a/fs/cifs/cifsencrypt.c b/fs/cifs/cifsencrypt.c index 46f5718754f9..d848bc0aac27 100644 --- a/fs/cifs/cifsencrypt.c +++ b/fs/cifs/cifsencrypt.c @@ -679,7 +679,7 @@ setup_ntlmv2_rsp(struct cifs_ses *ses, const struct nls_table *nls_cp) unlock: cifs_server_unlock(ses->server); setup_ntlmv2_rsp_ret: - kfree(tiblob); + kfree_sensitive(tiblob); return rc; } @@ -753,14 +753,14 @@ cifs_crypto_secmech_release(struct TCP_Server_Info *server) server->secmech.ccmaesdecrypt = NULL; } - kfree(server->secmech.sdesccmacaes); + kfree_sensitive(server->secmech.sdesccmacaes); server->secmech.sdesccmacaes = NULL; - kfree(server->secmech.sdeschmacsha256); + kfree_sensitive(server->secmech.sdeschmacsha256); server->secmech.sdeschmacsha256 = NULL; - kfree(server->secmech.sdeschmacmd5); + kfree_sensitive(server->secmech.sdeschmacmd5); server->secmech.sdeschmacmd5 = NULL; - kfree(server->secmech.sdescmd5); + kfree_sensitive(server->secmech.sdescmd5); server->secmech.sdescmd5 = NULL; - kfree(server->secmech.sdescsha512); + kfree_sensitive(server->secmech.sdescsha512); server->secmech.sdescsha512 = NULL; } diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c index 7ae6f2c08153..a43d5686c302 100644 --- a/fs/cifs/connect.c +++ b/fs/cifs/connect.c @@ -311,7 +311,7 @@ cifs_abort_connection(struct TCP_Server_Info *server) } server->sequence_number = 0; server->session_estab = false; - kfree(server->session_key.response); + kfree_sensitive(server->session_key.response); server->session_key.response = NULL; server->session_key.len = 0; server->lstrp = jiffies; @@ -1580,7 +1580,7 @@ cifs_put_tcp_session(struct TCP_Server_Info *server, int from_reconnect) cifs_crypto_secmech_release(server); - kfree(server->session_key.response); + kfree_sensitive(server->session_key.response); server->session_key.response = NULL; server->session_key.len = 0; kfree(server->hostname); @@ -4134,7 +4134,7 @@ cifs_setup_session(const unsigned int xid, struct cifs_ses *ses, if (ses->auth_key.response) { cifs_dbg(FYI, "Free previous auth_key.response = %p\n", ses->auth_key.response); - kfree(ses->auth_key.response); + kfree_sensitive(ses->auth_key.response); ses->auth_key.response = NULL; ses->auth_key.len = 0; } diff --git a/fs/cifs/fs_context.c b/fs/cifs/fs_context.c index 0e13dec86b25..45119597c765 100644 --- a/fs/cifs/fs_context.c +++ b/fs/cifs/fs_context.c @@ -791,6 +791,13 @@ do { \ cifs_sb->ctx->field = NULL; \ } while (0) +#define STEAL_STRING_SENSITIVE(cifs_sb, ctx, field) \ +do { \ + kfree_sensitive(ctx->field); \ + ctx->field = cifs_sb->ctx->field; \ + cifs_sb->ctx->field = NULL; \ +} while (0) + static int smb3_reconfigure(struct fs_context *fc) { struct smb3_fs_context *ctx = smb3_fc2context(fc); @@ -811,7 +818,7 @@ static int smb3_reconfigure(struct fs_context *fc) STEAL_STRING(cifs_sb, ctx, UNC); STEAL_STRING(cifs_sb, ctx, source); STEAL_STRING(cifs_sb, ctx, username); - STEAL_STRING(cifs_sb, ctx, password); + STEAL_STRING_SENSITIVE(cifs_sb, ctx, password); STEAL_STRING(cifs_sb, ctx, domainname); STEAL_STRING(cifs_sb, ctx, nodename); STEAL_STRING(cifs_sb, ctx, iocharset); @@ -1162,7 +1169,7 @@ static int smb3_fs_context_parse_param(struct fs_context *fc, } break; case Opt_pass: - kfree(ctx->password); + kfree_sensitive(ctx->password); ctx->password = NULL; if (strlen(param->string) == 0) break; @@ -1470,6 +1477,7 @@ static int smb3_fs_context_parse_param(struct fs_context *fc, return 0; cifs_parse_mount_err: + kfree_sensitive(ctx->password); return -EINVAL; } diff --git a/fs/cifs/misc.c b/fs/cifs/misc.c index 87f60f736731..85109a9a2146 100644 --- a/fs/cifs/misc.c +++ b/fs/cifs/misc.c @@ -1119,7 +1119,7 @@ cifs_alloc_hash(const char *name, void cifs_free_hash(struct crypto_shash **shash, struct sdesc **sdesc) { - kfree(*sdesc); + kfree_sensitive(*sdesc); *sdesc = NULL; if (*shash) crypto_free_shash(*shash); diff --git a/fs/cifs/sess.c b/fs/cifs/sess.c index 3af3b05b6c74..f1c3c6d9146c 100644 --- a/fs/cifs/sess.c +++ b/fs/cifs/sess.c @@ -1213,6 +1213,12 @@ sess_alloc_buffer(struct sess_data *sess_data, int wct) static void sess_free_buffer(struct sess_data *sess_data) { + int i; + + /* zero the session data before freeing, as it might contain sensitive info (keys, etc) */ + for (i = 0; i < 3; i++) + if (sess_data->iov[i].iov_base) + memzero_explicit(sess_data->iov[i].iov_base, sess_data->iov[i].iov_len); free_rsp_buf(sess_data->buf0_type, sess_data->iov[0].iov_base); sess_data->buf0_type = CIFS_NO_BUFFER; @@ -1374,7 +1380,7 @@ sess_auth_ntlmv2(struct sess_data *sess_data) sess_data->result = rc; sess_data->func = NULL; sess_free_buffer(sess_data); - kfree(ses->auth_key.response); + kfree_sensitive(ses->auth_key.response); ses->auth_key.response = NULL; } @@ -1513,7 +1519,7 @@ sess_auth_kerberos(struct sess_data *sess_data) sess_data->result = rc; sess_data->func = NULL; sess_free_buffer(sess_data); - kfree(ses->auth_key.response); + kfree_sensitive(ses->auth_key.response); ses->auth_key.response = NULL; } @@ -1648,7 +1654,7 @@ sess_auth_rawntlmssp_negotiate(struct sess_data *sess_data) rc = decode_ntlmssp_challenge(bcc_ptr, blob_len, ses); out_free_ntlmsspblob: - kfree(ntlmsspblob); + kfree_sensitive(ntlmsspblob); out: sess_free_buffer(sess_data); @@ -1658,9 +1664,9 @@ sess_auth_rawntlmssp_negotiate(struct sess_data *sess_data) } /* Else error. Cleanup */ - kfree(ses->auth_key.response); + kfree_sensitive(ses->auth_key.response); ses->auth_key.response = NULL; - kfree(ses->ntlmssp); + kfree_sensitive(ses->ntlmssp); ses->ntlmssp = NULL; sess_data->func = NULL; @@ -1759,7 +1765,7 @@ sess_auth_rawntlmssp_authenticate(struct sess_data *sess_data) } out_free_ntlmsspblob: - kfree(ntlmsspblob); + kfree_sensitive(ntlmsspblob); out: sess_free_buffer(sess_data); @@ -1767,9 +1773,9 @@ sess_auth_rawntlmssp_authenticate(struct sess_data *sess_data) rc = sess_establish_session(sess_data); /* Cleanup */ - kfree(ses->auth_key.response); + kfree_sensitive(ses->auth_key.response); ses->auth_key.response = NULL; - kfree(ses->ntlmssp); + kfree_sensitive(ses->ntlmssp); ses->ntlmssp = NULL; sess_data->func = NULL; @@ -1845,7 +1851,7 @@ int CIFS_SessSetup(const unsigned int xid, struct cifs_ses *ses, rc = sess_data->result; out: - kfree(sess_data); + kfree_sensitive(sess_data); return rc; } #endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */ diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c index 421be43af425..5094336cade6 100644 --- a/fs/cifs/smb2ops.c +++ b/fs/cifs/smb2ops.c @@ -4410,11 +4410,11 @@ crypt_message(struct TCP_Server_Info *server, int num_rqst, if (!rc && enc) memcpy(&tr_hdr->Signature, sign, SMB2_SIGNATURE_SIZE); - kfree(iv); + kfree_sensitive(iv); free_sg: - kfree(sg); + kfree_sensitive(sg); free_req: - kfree(req); + kfree_sensitive(req); return rc; } diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c index 6352ab32c7e7..8e531b8a09e6 100644 --- a/fs/cifs/smb2pdu.c +++ b/fs/cifs/smb2pdu.c @@ -1345,6 +1345,13 @@ SMB2_sess_alloc_buffer(struct SMB2_sess_data *sess_data) static void SMB2_sess_free_buffer(struct SMB2_sess_data *sess_data) { + int i; + + /* zero the session data before freeing, as it might contain sensitive info (keys, etc) */ + for (i = 0; i < 2; i++) + if (sess_data->iov[i].iov_base) + memzero_explicit(sess_data->iov[i].iov_base, sess_data->iov[i].iov_len); + free_rsp_buf(sess_data->buf0_type, sess_data->iov[0].iov_base); sess_data->buf0_type = CIFS_NO_BUFFER; } @@ -1417,6 +1424,9 @@ SMB2_auth_kerberos(struct SMB2_sess_data *sess_data) struct smb2_sess_setup_rsp *rsp = NULL; bool is_binding = false; + /* initialize it to NULL so we can check/free it on exit */ + ses->auth_key.response = NULL; + rc = SMB2_sess_alloc_buffer(sess_data); if (rc) goto out; @@ -1477,6 +1487,8 @@ SMB2_auth_kerberos(struct SMB2_sess_data *sess_data) out_put_spnego_key: key_invalidate(spnego_key); key_put(spnego_key); + if (rc) + kfree_sensitive(ses->auth_key.response); out: sess_data->result = rc; sess_data->func = NULL; @@ -1573,7 +1585,7 @@ SMB2_sess_auth_rawntlmssp_negotiate(struct SMB2_sess_data *sess_data) } out: - kfree(ntlmssp_blob); + kfree_sensitive(ntlmssp_blob); SMB2_sess_free_buffer(sess_data); if (!rc) { sess_data->result = 0; @@ -1581,7 +1593,7 @@ SMB2_sess_auth_rawntlmssp_negotiate(struct SMB2_sess_data *sess_data) return; } out_err: - kfree(ses->ntlmssp); + kfree_sensitive(ses->ntlmssp); ses->ntlmssp = NULL; sess_data->result = rc; sess_data->func = NULL; @@ -1657,9 +1669,9 @@ SMB2_sess_auth_rawntlmssp_authenticate(struct SMB2_sess_data *sess_data) } #endif out: - kfree(ntlmssp_blob); + kfree_sensitive(ntlmssp_blob); SMB2_sess_free_buffer(sess_data); - kfree(ses->ntlmssp); + kfree_sensitive(ses->ntlmssp); ses->ntlmssp = NULL; sess_data->result = rc; sess_data->func = NULL; @@ -1737,7 +1749,7 @@ SMB2_sess_setup(const unsigned int xid, struct cifs_ses *ses, cifs_server_dbg(VFS, "signing requested but authenticated as guest\n"); rc = sess_data->result; out: - kfree(sess_data); + kfree_sensitive(sess_data); return rc; }