From patchwork Tue Jun 23 00:32:28 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tyler Hicks X-Patchwork-Id: 11619503 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 82343912 for ; Tue, 23 Jun 2020 00:35:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 67B842053B for ; Tue, 23 Jun 2020 00:35:04 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b="FPiNWHnk" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732077AbgFWAe7 (ORCPT ); Mon, 22 Jun 2020 20:34:59 -0400 Received: from linux.microsoft.com ([13.77.154.182]:47448 "EHLO linux.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731889AbgFWAeQ (ORCPT ); Mon, 22 Jun 2020 20:34:16 -0400 Received: from sequoia.work.tihix.com (162-237-133-238.lightspeed.rcsntx.sbcglobal.net [162.237.133.238]) by linux.microsoft.com (Postfix) with ESMTPSA id 0B61B20B4781; Mon, 22 Jun 2020 17:34:14 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 0B61B20B4781 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1592872455; bh=tPM2cLdleiXTdhTcx3SJbwPTbqR3C7p+Rm6GApOkV+U=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=FPiNWHnk28C2EkEMbDX9KqsktQr53PywyM67fEEx9JgBdcaTX8KRLOPzjOPcJ1iFv pw/EA03DivehJgoaKkKBepalnBbg02L5fJ/duZScba+5aJB8KRfJ7G5qXs6KCq5szL JpPT8UiDfTI5BLJgyOS83vUbKG7MSukUiZ4TAUTQ= From: Tyler Hicks To: Mimi Zohar , Dmitry Kasatkin Cc: James Morris , "Serge E . Hallyn" , Lakshmi Ramasubramanian , Prakhar Srivastava , linux-kernel@vger.kernel.org, linux-integrity@vger.kernel.org, linux-security-module@vger.kernel.org Subject: [PATCH 04/12] ima: Free the entire rule if it fails to parse Date: Mon, 22 Jun 2020 19:32:28 -0500 Message-Id: <20200623003236.830149-5-tyhicks@linux.microsoft.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200623003236.830149-1-tyhicks@linux.microsoft.com> References: <20200623003236.830149-1-tyhicks@linux.microsoft.com> MIME-Version: 1.0 Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: Use ima_free_rule() to fix memory leaks of allocated ima_rule_entry members, such as .fsname and .keyrings, when an error is encountered during rule parsing. Set the args_p pointer to NULL after freeing it in the error path of ima_lsm_rule_init() so that it isn't freed twice. This fixes a memory leak seen when loading an rule that contains an additional piece of allocated memory, such as an fsname, followed by an invalid conditional: # echo "measure fsname=tmpfs bad=cond" > /sys/kernel/security/ima/policy -bash: echo: write error: Invalid argument # echo scan > /sys/kernel/debug/kmemleak # cat /sys/kernel/debug/kmemleak unreferenced object 0xffff98e7e4ece6c0 (size 8): comm "bash", pid 672, jiffies 4294791843 (age 21.855s) hex dump (first 8 bytes): 74 6d 70 66 73 00 6b a5 tmpfs.k. backtrace: [<00000000abab7413>] kstrdup+0x2e/0x60 [<00000000f11ede32>] ima_parse_add_rule+0x7d4/0x1020 [<00000000f883dd7a>] ima_write_policy+0xab/0x1d0 [<00000000b17cf753>] vfs_write+0xde/0x1d0 [<00000000b8ddfdea>] ksys_write+0x68/0xe0 [<00000000b8e21e87>] do_syscall_64+0x56/0xa0 [<0000000089ea7b98>] entry_SYSCALL_64_after_hwframe+0x44/0xa9 Fixes: f1b08bbcbdaf ("ima: define a new policy condition based on the filesystem name") Fixes: 2b60c0ecedf8 ("IMA: Read keyrings= option from the IMA policy") Signed-off-by: Tyler Hicks --- security/integrity/ima/ima_policy.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c index 94ca3b8abb69..ee5152ecd3d9 100644 --- a/security/integrity/ima/ima_policy.c +++ b/security/integrity/ima/ima_policy.c @@ -919,6 +919,7 @@ static int ima_lsm_rule_init(struct ima_rule_entry *entry, if (ima_rules == &ima_default_rules) { kfree(entry->lsm[lsm_rule].args_p); + entry->lsm[lsm_rule].args_p = NULL; result = -EINVAL; } else result = 0; @@ -1410,7 +1411,7 @@ ssize_t ima_parse_add_rule(char *rule) result = ima_parse_rule(p, entry); if (result) { - kfree(entry); + ima_free_rule(entry); integrity_audit_msg(AUDIT_INTEGRITY_STATUS, NULL, NULL, op, "invalid-policy", result, audit_info);