From patchwork Fri Feb 5 09:45:37 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nicolas Iooss X-Patchwork-Id: 12069775 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6E0FCC433E9 for ; Fri, 5 Feb 2021 09:53:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1A7AA64FBC for ; Fri, 5 Feb 2021 09:53:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229767AbhBEJxg (ORCPT ); Fri, 5 Feb 2021 04:53:36 -0500 Received: from mx1.polytechnique.org ([129.104.30.34]:46889 "EHLO mx1.polytechnique.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229554AbhBEJqw (ORCPT ); Fri, 5 Feb 2021 04:46:52 -0500 Received: from localhost.localdomain (85-168-38-217.rev.numericable.fr [85.168.38.217]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by ssl.polytechnique.org (Postfix) with ESMTPSA id 6EC3456129F for ; Fri, 5 Feb 2021 10:46:09 +0100 (CET) From: Nicolas Iooss To: selinux@vger.kernel.org Subject: [PATCH 1/3] libsepol/cil: fix NULL pointer dereference with empty macro argument Date: Fri, 5 Feb 2021 10:45:37 +0100 Message-Id: <20210205094539.388854-1-nicolas.iooss@m4x.org> X-Mailer: git-send-email 2.30.0 MIME-Version: 1.0 X-AV-Checked: ClamAV using ClamSMTP at svoboda.polytechnique.org (Fri Feb 5 10:46:09 2021 +0100 (CET)) X-Org-Mail: nicolas.iooss.2010@polytechnique.org Precedence: bulk List-ID: X-Mailing-List: selinux@vger.kernel.org OSS-Fuzz found a Null-dereference READ in the CIL compiler when trying to compile the following policy: (macro m((name n))) (call m(())) When calling the macro, the name (in variable "pc") is NULL, which triggers a NULL pointer dereference when using it as a key in __cil_insert_name(). The stack trace is: #0 0x7f4662655a85 in __strlen_avx2 (/usr/lib/libc.so.6+0x162a85) #1 0x556d0b6d150c in __interceptor_strlen.part.0 (/selinux/libsepol/fuzz/fuzz-secilc+0x44850c) #2 0x556d0ba74ed6 in symhash /selinux/libsepol/src/symtab.c:22:9 #3 0x556d0b9ef50d in hashtab_search /selinux/libsepol/src/hashtab.c:186:11 #4 0x556d0b928e1f in cil_symtab_get_datum /selinux/libsepol/src/../cil/src/cil_symtab.c:121:37 #5 0x556d0b8f28f4 in __cil_insert_name /selinux/libsepol/src/../cil/src/cil_resolve_ast.c:96:2 #6 0x556d0b908184 in cil_resolve_call1 /selinux/libsepol/src/../cil/src/cil_resolve_ast.c:2835:12 #7 0x556d0b91b404 in __cil_resolve_ast_node /selinux/libsepol/src/../cil/src/cil_resolve_ast.c #8 0x556d0b91380f in __cil_resolve_ast_node_helper /selinux/libsepol/src/../cil/src/cil_resolve_ast.c:3773:7 #9 0x556d0b932230 in cil_tree_walk_core /selinux/libsepol/src/../cil/src/cil_tree.c:263:9 #10 0x556d0b932230 in cil_tree_walk /selinux/libsepol/src/../cil/src/cil_tree.c:307:7 #11 0x556d0b932326 in cil_tree_walk_core /selinux/libsepol/src/../cil/src/cil_tree.c:275:9 #12 0x556d0b932326 in cil_tree_walk /selinux/libsepol/src/../cil/src/cil_tree.c:307:7 #13 0x556d0b911189 in cil_resolve_ast /selinux/libsepol/src/../cil/src/cil_resolve_ast.c:3941:8 #14 0x556d0b798729 in cil_compile /selinux/libsepol/src/../cil/src/cil.c:550:7 Fixes: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=28544 Signed-off-by: Nicolas Iooss Acked-by: James Carter --- libsepol/cil/src/cil_resolve_ast.c | 79 ++++++++++++++++++++++++++++++ 1 file changed, 79 insertions(+) diff --git a/libsepol/cil/src/cil_resolve_ast.c b/libsepol/cil/src/cil_resolve_ast.c index 0c85eabe5a81..9300cd2be9be 100644 --- a/libsepol/cil/src/cil_resolve_ast.c +++ b/libsepol/cil/src/cil_resolve_ast.c @@ -2828,6 +2828,12 @@ int cil_resolve_call1(struct cil_tree_node *current, void *extra_args) switch (flavor) { case CIL_NAME: { struct cil_name *name; + if (pc->data == NULL) { + cil_tree_log(current, CIL_ERR, "Invalid macro parameter"); + cil_destroy_args(new_arg); + rc = SEPOL_ERR; + goto exit; + } name = __cil_insert_name(args->db, pc->data, current); if (name != NULL) { new_arg->arg = (struct cil_symtab_datum *)name; @@ -2837,21 +2843,57 @@ int cil_resolve_call1(struct cil_tree_node *current, void *extra_args) } break; case CIL_TYPE: + if (pc->data == NULL) { + cil_tree_log(current, CIL_ERR, "Invalid macro parameter"); + cil_destroy_args(new_arg); + rc = SEPOL_ERR; + goto exit; + } new_arg->arg_str = pc->data; break; case CIL_ROLE: + if (pc->data == NULL) { + cil_tree_log(current, CIL_ERR, "Invalid macro parameter"); + cil_destroy_args(new_arg); + rc = SEPOL_ERR; + goto exit; + } new_arg->arg_str = pc->data; break; case CIL_USER: + if (pc->data == NULL) { + cil_tree_log(current, CIL_ERR, "Invalid macro parameter"); + cil_destroy_args(new_arg); + rc = SEPOL_ERR; + goto exit; + } new_arg->arg_str = pc->data; break; case CIL_SENS: + if (pc->data == NULL) { + cil_tree_log(current, CIL_ERR, "Invalid macro parameter"); + cil_destroy_args(new_arg); + rc = SEPOL_ERR; + goto exit; + } new_arg->arg_str = pc->data; break; case CIL_CAT: + if (pc->data == NULL) { + cil_tree_log(current, CIL_ERR, "Invalid macro parameter"); + cil_destroy_args(new_arg); + rc = SEPOL_ERR; + goto exit; + } new_arg->arg_str = pc->data; break; case CIL_BOOL: + if (pc->data == NULL) { + cil_tree_log(current, CIL_ERR, "Invalid macro parameter"); + cil_destroy_args(new_arg); + rc = SEPOL_ERR; + goto exit; + } new_arg->arg_str = pc->data; break; case CIL_CATSET: { @@ -2871,6 +2913,11 @@ int cil_resolve_call1(struct cil_tree_node *current, void *extra_args) cil_list_append(((struct cil_symtab_datum*)catset)->nodes, CIL_LIST_ITEM, cat_node); new_arg->arg = (struct cil_symtab_datum*)catset; + } else if (pc->data == NULL) { + cil_tree_log(current, CIL_ERR, "Invalid macro parameter"); + cil_destroy_args(new_arg); + rc = SEPOL_ERR; + goto exit; } else { new_arg->arg_str = pc->data; } @@ -2896,6 +2943,11 @@ int cil_resolve_call1(struct cil_tree_node *current, void *extra_args) cil_list_append(((struct cil_symtab_datum*)level)->nodes, CIL_LIST_ITEM, lvl_node); new_arg->arg = (struct cil_symtab_datum*)level; + } else if (pc->data == NULL) { + cil_tree_log(current, CIL_ERR, "Invalid macro parameter"); + cil_destroy_args(new_arg); + rc = SEPOL_ERR; + goto exit; } else { new_arg->arg_str = pc->data; } @@ -2921,6 +2973,11 @@ int cil_resolve_call1(struct cil_tree_node *current, void *extra_args) cil_list_append(((struct cil_symtab_datum*)range)->nodes, CIL_LIST_ITEM, range_node); new_arg->arg = (struct cil_symtab_datum*)range; + } else if (pc->data == NULL) { + cil_tree_log(current, CIL_ERR, "Invalid macro parameter"); + cil_destroy_args(new_arg); + rc = SEPOL_ERR; + goto exit; } else { new_arg->arg_str = pc->data; } @@ -2946,6 +3003,11 @@ int cil_resolve_call1(struct cil_tree_node *current, void *extra_args) cil_list_append(((struct cil_symtab_datum*)ipaddr)->nodes, CIL_LIST_ITEM, addr_node); new_arg->arg = (struct cil_symtab_datum*)ipaddr; + } else if (pc->data == NULL) { + cil_tree_log(current, CIL_ERR, "Invalid macro parameter"); + cil_destroy_args(new_arg); + rc = SEPOL_ERR; + goto exit; } else { new_arg->arg_str = pc->data; } @@ -2953,9 +3015,21 @@ int cil_resolve_call1(struct cil_tree_node *current, void *extra_args) break; } case CIL_CLASS: + if (pc->data == NULL) { + cil_tree_log(current, CIL_ERR, "Invalid macro parameter"); + cil_destroy_args(new_arg); + rc = SEPOL_ERR; + goto exit; + } new_arg->arg_str = pc->data; break; case CIL_MAP_CLASS: + if (pc->data == NULL) { + cil_tree_log(current, CIL_ERR, "Invalid macro parameter"); + cil_destroy_args(new_arg); + rc = SEPOL_ERR; + goto exit; + } new_arg->arg_str = pc->data; break; case CIL_CLASSPERMISSION: { @@ -2976,6 +3050,11 @@ int cil_resolve_call1(struct cil_tree_node *current, void *extra_args) cp_node->data = cp; cil_list_append(cp->datum.nodes, CIL_LIST_ITEM, cp_node); new_arg->arg = (struct cil_symtab_datum*)cp; + } else if (pc->data == NULL) { + cil_tree_log(current, CIL_ERR, "Invalid macro parameter"); + cil_destroy_args(new_arg); + rc = SEPOL_ERR; + goto exit; } else { new_arg->arg_str = pc->data; }