From patchwork Thu Jul 25 16:11:05 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vit Mojzis X-Patchwork-Id: 13742054 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D5C2619B584 for ; Thu, 25 Jul 2024 16:11:14 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721923876; cv=none; b=c30jxzzmCot0jM+bSWw26eiojiahhYI1lzrG+dAh1TsDW76B6S6TY93bIx6DEIfT37N7NlqVgYhAqmkseTGmOC1CJAosDw5Y6IyxhxfEGmInelVFGb4IxO95G2/CnOXLcFmKxDKgMBQ1UK0b2fZ1HF4LxbzVdVVf2EIT+b7xBi4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721923876; c=relaxed/simple; bh=s1k0QGPYMYXScl8nZ9I0HKbb+YULQicVIyGDFp+nFGg=; h=From:To:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Fk/w5MhXXBOrdApok24Nj6MVsfp3/9zDxdUeMgdlbF5uQfvRb35Baku6Evpjj13H14R+5Phg09froaZhpVbZ1r2MWsaIztnBfeeIyGE619CiBEbpcOx4f9Di4su3Sw+RzTtnwZbdcYHdRHz7JsFtM795u/PCyJRc6qBtXa3PKmo= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=E8sUvBw+; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="E8sUvBw+" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1721923873; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=XM0HryaWuk/il8a7aH+UXFkBZ6VbBg6eUZ0hf2Mu+as=; b=E8sUvBw+ZBV047ca7b0fiIo6JQaddboyf+QUyRRGlJQzZVzrTo3tQVrAj0DWiJBhgo88qx lHCcqtIc9jxDseCcrT+zMqJp0OoXN2L/7Yy7gz820jOew8HU0FMMqZkhIiQrywtPHwLGlF MTZcUvp0y5IOGvkBTZ4hSVOCAilxXP4= Received: from mx-prod-mc-02.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-646-IAIsywbuPE-Zx5OB74ZaYQ-1; Thu, 25 Jul 2024 12:11:12 -0400 X-MC-Unique: IAIsywbuPE-Zx5OB74ZaYQ-1 Received: from mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.12]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-02.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 7E20A1955F3D for ; Thu, 25 Jul 2024 16:11:11 +0000 (UTC) Received: from fedora.redhat.com (unknown [10.45.224.30]) by mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 963E619560AE for ; Thu, 25 Jul 2024 16:11:10 +0000 (UTC) From: Vit Mojzis To: selinux@vger.kernel.org Subject: [PATCH v4] libsemanage: Preserve file context and ownership in policy store Date: Thu, 25 Jul 2024 18:11:05 +0200 Message-ID: <20240725161107.1446978-1-vmojzis@redhat.com> In-Reply-To: References: Precedence: bulk X-Mailing-List: selinux@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.0 on 10.30.177.12 Make sure that file context (all parts) and ownership of files/directories in policy store does not change no matter which user and under which context executes policy rebuild. Fixes: # semodule -B # ls -lZ /etc/selinux/targeted/contexts/files -rw-r--r--. 1 root root unconfined_u:object_r:file_context_t:s0 421397 Jul 11 09:57 file_contexts -rw-r--r--. 1 root root unconfined_u:object_r:file_context_t:s0 593470 Jul 11 09:57 file_contexts.bin -rw-r--r--. 1 root root unconfined_u:object_r:file_context_t:s0 14704 Jul 11 09:57 file_contexts.homedirs -rw-r--r--. 1 root root unconfined_u:object_r:file_context_t:s0 20289 Jul 11 09:57 file_contexts.homedirs.bin SELinux user changed from system_u to the user used to execute semodule # capsh --user=testuser --caps="cap_dac_override,cap_chown+eip" --addamb=cap_dac_override,cap_chown -- -c "semodule -B" # ls -lZ /etc/selinux/targeted/contexts/files -rw-r--r--. 1 testuser testuser unconfined_u:object_r:file_context_t:s0 421397 Jul 19 09:10 file_contexts -rw-r--r--. 1 testuser testuser unconfined_u:object_r:file_context_t:s0 593470 Jul 19 09:10 file_contexts.bin -rw-r--r--. 1 testuser testuser unconfined_u:object_r:file_context_t:s0 14704 Jul 19 09:10 file_contexts.homedirs -rw-r--r--. 1 testuser testuser unconfined_u:object_r:file_context_t:s0 20289 Jul 19 09:10 file_contexts.homedirs.bin Both file context and ownership changed -- causes remote login failures and other issues in some scenarios. Signed-off-by: Vit Mojzis Acked-by: Stephen Smalley --- libsemanage/src/semanage_store.c | 31 +++++++++++++++++++++++++++++++ libsemanage/src/semanage_store.h | 1 + 2 files changed, 32 insertions(+) diff --git a/libsemanage/src/semanage_store.c b/libsemanage/src/semanage_store.c index 27c5d349..95596a93 100644 --- a/libsemanage/src/semanage_store.c +++ b/libsemanage/src/semanage_store.c @@ -36,6 +36,7 @@ typedef struct dbase_policydb dbase_t; #include "database_policydb.h" #include "handle.h" +#include #include #include #include @@ -767,6 +768,7 @@ int semanage_copy_file(const char *src, const char *dst, mode_t mode, if (!retval && rename(tmp, dst) == -1) return -1; + semanage_setfiles(dst); out: errno = errsv; return retval; @@ -819,6 +821,8 @@ static int semanage_copy_dir_flags(const char *src, const char *dst, int flag) goto cleanup; } umask(mask); + + semanage_setfiles(dst); } for (i = 0; i < len; i++) { @@ -837,6 +841,7 @@ static int semanage_copy_dir_flags(const char *src, const char *dst, int flag) goto cleanup; } umask(mask); + semanage_setfiles(path2); } else if (S_ISREG(sb.st_mode) && flag == 1) { mask = umask(0077); if (semanage_copy_file(path, path2, sb.st_mode, @@ -938,6 +943,7 @@ int semanage_mkdir(semanage_handle_t *sh, const char *path) } umask(mask); + semanage_setfiles(path); } else { /* check that it really is a directory */ @@ -1614,16 +1620,19 @@ static int semanage_validate_and_compile_fcontexts(semanage_handle_t * sh) semanage_final_path(SEMANAGE_FINAL_TMP, SEMANAGE_FC)) != 0) { goto cleanup; } + semanage_setfiles(semanage_final_path(SEMANAGE_FINAL_TMP, SEMANAGE_FC_BIN)); if (sefcontext_compile(sh, semanage_final_path(SEMANAGE_FINAL_TMP, SEMANAGE_FC_LOCAL)) != 0) { goto cleanup; } + semanage_setfiles(semanage_final_path(SEMANAGE_FINAL_TMP, SEMANAGE_FC_LOCAL_BIN)); if (sefcontext_compile(sh, semanage_final_path(SEMANAGE_FINAL_TMP, SEMANAGE_FC_HOMEDIRS)) != 0) { goto cleanup; } + semanage_setfiles(semanage_final_path(SEMANAGE_FINAL_TMP, SEMANAGE_FC_HOMEDIRS_BIN)); status = 0; cleanup: @@ -3018,3 +3027,25 @@ int semanage_nc_sort(semanage_handle_t * sh, const char *buf, size_t buf_len, return 0; } + +/* Make sure the file context and ownership of files in the policy + * store does not change */ +void semanage_setfiles(const char *path){ + struct stat sb; + int fd; + /* Fix the user and role portions of the context, ignore errors + * since this is not a critical operation */ + selinux_restorecon(path, SELINUX_RESTORECON_SET_SPECFILE_CTX | SELINUX_RESTORECON_IGNORE_NOENTRY); + + /* Make sure "path" is owned by root */ + if ((geteuid() != 0 || getegid() != 0) && + ((fd = open(path, O_RDONLY)) != -1)){ + /* Skip files with the SUID or SGID bit set -- abuse protection */ + if ((fstat(fd, &sb) != -1) && + !(S_ISREG(sb.st_mode) && + (sb.st_mode & (S_ISUID | S_ISGID)))) + fchown(fd, 0, 0); + + close(fd); + } +} diff --git a/libsemanage/src/semanage_store.h b/libsemanage/src/semanage_store.h index 1fc77da8..e21dadeb 100644 --- a/libsemanage/src/semanage_store.h +++ b/libsemanage/src/semanage_store.h @@ -124,6 +124,7 @@ int semanage_get_cil_paths(semanage_handle_t * sh, semanage_module_info_t *modin int semanage_get_active_modules(semanage_handle_t *sh, semanage_module_info_t **modinfo, int *num_modules); +void semanage_setfiles(const char *path); /* lock file routines */ int semanage_get_trans_lock(semanage_handle_t * sh);