From patchwork Thu Mar 8 17:00:51 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tycho Andersen X-Patchwork-Id: 10268513 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 231EC602C8 for ; Thu, 8 Mar 2018 17:02:05 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 1426A29339 for ; Thu, 8 Mar 2018 17:02:05 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 08E2529459; Thu, 8 Mar 2018 17:02:05 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.2 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from mother.openwall.net (mother.openwall.net [195.42.179.200]) by mail.wl.linuxfoundation.org (Postfix) with SMTP id 8BB2929339 for ; Thu, 8 Mar 2018 17:01:59 +0000 (UTC) Received: (qmail 9229 invoked by uid 550); 8 Mar 2018 17:01:57 -0000 Mailing-List: contact kernel-hardening-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-ID: Delivered-To: mailing list kernel-hardening@lists.openwall.com Received: (qmail 8153 invoked from network); 8 Mar 2018 17:01:56 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=tycho-ws.20150623.gappssmtp.com; s=20150623; h=from:to:cc:subject:date:message-id; bh=BAOnLg8xz/HX7iBPazryjgGzDg7+l7+F3AbP7nH4BXY=; b=qKanPzRLjWFz0j+qKbo4UGrmHWLQbU5kh6qwhrleLk2vnGzkzFjN4cyX+NFHRaRNtV 1rCuhLbbR3EajtvrWRolieVUWMmEFVxh0vWhczLTJqi63RAvq1FipuO38ag8PB3Bjy6o 6pMRFtrmpmgEfI4afbl63A9A38FQLYAS4A29hkz7WMnwnIKVtd6xGp/epWPThMElBiTe WtatIuREss9+EneQXVZUJgRvLtolYMyXb7uWKPI+cZ8lb9+iAE9Od1jRibld5H3Lm6kJ 9Ihz3Hk1v2DvBKrB8ZMxJDRtEseZ8SXrvaS4SsMXIYd1XpYmh2ampVScKTznYJ5APwFL n+Cg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id; bh=BAOnLg8xz/HX7iBPazryjgGzDg7+l7+F3AbP7nH4BXY=; b=J1jVfiLw9zTuZMx2Q0akMtFwq0KPMBac0fxNi1mbs0PEmF/NdkDU18cFFWmaaIYSO2 n0xfos43UNHzdtz2WR0aLkGNwpI6pqtj80lDd2e3qb4nqYVb7qj42Q9XERgscSL6MW9u GGRIRXUmw1JxZJYo+DMXS4UwLK7cSwnm4bMDdZxI4yHj9zJHZX5jSPkelNGsZAf5ix1k Dk8VhsiCnK52uGlJrjUKoBZA9Mp6G6euBvkxCLPIy/TOXAKPbZeyB67ydlXJ3ZYMjPH4 Q1QBSTji4wRKy4j7pC6JCplYDhuKXeycuRMJlOOSwxUMwMCcBkmKSvvT10EtD/zZiNge AxLA== X-Gm-Message-State: AElRT7G3ardQCOHtNOokARD1cV6yjHsvKtNf8iEk3GrTN/525Ln4sFj/ gjtPRARZPgDAlmkSHrEnMGdmTPw3 X-Google-Smtp-Source: AG47ELsuTDEurLqCSKVLsSf7zxVJcB222VO0ym5CmvPki01vbw1v4MRlNBWYwV97bfsFjPSl7wlhAA== X-Received: by 10.233.239.82 with SMTP id d79mr38837456qkg.190.1520528504063; Thu, 08 Mar 2018 09:01:44 -0800 (PST) From: Tycho Andersen To: Mimi Zohar , Dmitry Kasatkin Cc: linux-ima-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org, kernel-hardening@lists.openwall.com, Tycho Andersen Subject: [PATCH] ima: drop vla in ima_audit_measurement() Date: Thu, 8 Mar 2018 10:00:51 -0700 Message-Id: <20180308170051.30840-1-tycho@tycho.ws> X-Mailer: git-send-email 2.14.1 X-Virus-Scanned: ClamAV using ClamSMTP In keeping with the directive to get rid of VLAs [1], let's drop the VLA from ima_audit_measurement(). We need to adjust the return type of ima_audit_measurement, because now this function can fail if an allocation fails. [1]: https://lkml.org/lkml/2018/3/7/621 Signed-off-by: Tycho Andersen --- security/integrity/ima/ima.h | 4 ++-- security/integrity/ima/ima_api.c | 31 +++++++++++++++++++++++-------- security/integrity/ima/ima_main.c | 7 +++++-- 3 files changed, 30 insertions(+), 12 deletions(-) diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h index d52b487ad259..8e2470f72f7f 100644 --- a/security/integrity/ima/ima.h +++ b/security/integrity/ima/ima.h @@ -201,8 +201,8 @@ void ima_store_measurement(struct integrity_iint_cache *iint, struct file *file, const unsigned char *filename, struct evm_ima_xattr_data *xattr_value, int xattr_len, int pcr); -void ima_audit_measurement(struct integrity_iint_cache *iint, - const unsigned char *filename); +int ima_audit_measurement(struct integrity_iint_cache *iint, + const unsigned char *filename); int ima_alloc_init_template(struct ima_event_data *event_data, struct ima_template_entry **entry); int ima_store_template(struct ima_template_entry *entry, int violation, diff --git a/security/integrity/ima/ima_api.c b/security/integrity/ima/ima_api.c index 08fe405338e1..008d3887ae00 100644 --- a/security/integrity/ima/ima_api.c +++ b/security/integrity/ima/ima_api.c @@ -304,17 +304,28 @@ void ima_store_measurement(struct integrity_iint_cache *iint, ima_free_template_entry(entry); } -void ima_audit_measurement(struct integrity_iint_cache *iint, - const unsigned char *filename) +int ima_audit_measurement(struct integrity_iint_cache *iint, + const unsigned char *filename) { struct audit_buffer *ab; - char hash[(iint->ima_hash->length * 2) + 1]; + char *hash, *algo_hash; const char *algo_name = hash_algo_name[iint->ima_hash->algo]; - char algo_hash[sizeof(hash) + strlen(algo_name) + 2]; - int i; + int i, hash_len, algo_hash_len; if (iint->flags & IMA_AUDITED) - return; + return 0; + + hash_len = (iint->ima_hash->length * 2) + 1; + hash = kzalloc(hash_len, GFP_KERNEL); + if (!hash) + return -ENOMEM; + + algo_hash_len = hash_len + strlen(algo_name) + 2; + algo_hash = kzalloc(algo_hash_len, GFP_KERNEL); + if (!algo_hash) { + kfree(hash); + return -ENOMEM; + } for (i = 0; i < iint->ima_hash->length; i++) hex_byte_pack(hash + (i * 2), iint->ima_hash->digest[i]); @@ -323,18 +334,22 @@ void ima_audit_measurement(struct integrity_iint_cache *iint, ab = audit_log_start(current->audit_context, GFP_KERNEL, AUDIT_INTEGRITY_RULE); if (!ab) - return; + goto out; audit_log_format(ab, "file="); audit_log_untrustedstring(ab, filename); audit_log_format(ab, " hash="); - snprintf(algo_hash, sizeof(algo_hash), "%s:%s", algo_name, hash); + snprintf(algo_hash, algo_hash_len, "%s:%s", algo_name, hash); audit_log_untrustedstring(ab, algo_hash); audit_log_task_info(ab, current); audit_log_end(ab); iint->flags |= IMA_AUDITED; +out: + kfree(hash); + kfree(algo_hash); + return 0; } /* diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c index 2cfb0c714967..356faae6f09c 100644 --- a/security/integrity/ima/ima_main.c +++ b/security/integrity/ima/ima_main.c @@ -288,8 +288,11 @@ static int process_measurement(struct file *file, char *buf, loff_t size, xattr_value, xattr_len, opened); inode_unlock(inode); } - if (action & IMA_AUDIT) - ima_audit_measurement(iint, pathname); + if (action & IMA_AUDIT) { + rc = ima_audit_measurement(iint, pathname); + if (rc < 0) + goto out_locked; + } if ((file->f_flags & O_DIRECT) && (iint->flags & IMA_PERMIT_DIRECTIO)) rc = 0;