From: Enzo Matsumiya <ematsumiya@xxxxxxx> [ Upstream commit a4e430c8c8ba96be8c6ec4f2eb108bb8bcbee069 ] Replace kfree with kfree_sensitive, or prepend memzero_explicit() in other cases, when freeing sensitive material that could still be left in memory. Signed-off-by: Enzo Matsumiya <ematsumiya@xxxxxxx> Reported-by: kernel test robot <oliver.sang@xxxxxxxxx> Link: https://lore.kernel.org/r/202209201529.ec633796-oliver.sang@xxxxxxxxx Reviewed-by: Paulo Alcantara (SUSE) <pc@xxxxxx> Reviewed-by: Ronnie Sahlberg <lsahlber@xxxxxxxxxx> Signed-off-by: Steve French <stfrench@xxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- 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 | 19 ++++++++++++++----- 7 files changed, 52 insertions(+), 29 deletions(-) diff --git a/fs/cifs/cifsencrypt.c b/fs/cifs/cifsencrypt.c index 663cb9db4908..419cbdadf248 100644 --- a/fs/cifs/cifsencrypt.c +++ b/fs/cifs/cifsencrypt.c @@ -680,7 +680,7 @@ 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; } @@ -754,14 +754,14 @@ 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 bdc3efdb1221..901d9b232e2c 100644 --- a/fs/cifs/connect.c +++ b/fs/cifs/connect.c @@ -315,7 +315,7 @@ 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; @@ -1535,7 +1535,7 @@ 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); @@ -4059,7 +4059,7 @@ 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 8dc0d923ef6a..ff3ad09f2cd4 100644 --- a/fs/cifs/fs_context.c +++ b/fs/cifs/fs_context.c @@ -790,6 +790,13 @@ 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); @@ -810,7 +817,7 @@ 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); @@ -1154,7 +1161,7 @@ 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; @@ -1462,6 +1469,7 @@ 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 197f3c09d3f3..2baf23b3d572 100644 --- a/fs/cifs/misc.c +++ b/fs/cifs/misc.c @@ -1129,7 +1129,7 @@ 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 02c8b2906196..30143d3d0a34 100644 --- a/fs/cifs/sess.c +++ b/fs/cifs/sess.c @@ -1211,6 +1211,12 @@ 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; @@ -1372,7 +1378,7 @@ 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; } @@ -1511,7 +1517,7 @@ 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; } @@ -1646,7 +1652,7 @@ 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); @@ -1656,9 +1662,9 @@ 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; @@ -1757,7 +1763,7 @@ sess_auth_rawntlmssp_authenticate(struct sess_data *sess_data) } out_free_ntlmsspblob: - kfree(ntlmsspblob); + kfree_sensitive(ntlmsspblob); out: sess_free_buffer(sess_data); @@ -1765,9 +1771,9 @@ 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; @@ -1843,6 +1849,6 @@ 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; } diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c index cc180d37b8ce..340ca57fa361 100644 --- a/fs/cifs/smb2ops.c +++ b/fs/cifs/smb2ops.c @@ -4691,11 +4691,11 @@ 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 31d37afae741..f3032cfafedc 100644 --- a/fs/cifs/smb2pdu.c +++ b/fs/cifs/smb2pdu.c @@ -1344,6 +1344,13 @@ 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; } @@ -1476,6 +1483,8 @@ 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; @@ -1572,7 +1581,7 @@ SMB2_sess_auth_rawntlmssp_negotiate(struct SMB2_sess_data *sess_data) } out: - kfree(ntlmssp_blob); + memzero_explicit(ntlmssp_blob, blob_length); SMB2_sess_free_buffer(sess_data); if (!rc) { sess_data->result = 0; @@ -1580,7 +1589,7 @@ 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; @@ -1656,9 +1665,9 @@ SMB2_sess_auth_rawntlmssp_authenticate(struct SMB2_sess_data *sess_data) } #endif out: - kfree(ntlmssp_blob); + memzero_explicit(ntlmssp_blob, blob_length); SMB2_sess_free_buffer(sess_data); - kfree(ses->ntlmssp); + kfree_sensitive(ses->ntlmssp); ses->ntlmssp = NULL; sess_data->result = rc; sess_data->func = NULL; @@ -1736,7 +1745,7 @@ 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; } -- 2.35.1
