From patchwork Fri Jul 22 08:21:25 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jianglei Nie X-Patchwork-Id: 12926106 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E30F7C433EF for ; Fri, 22 Jul 2022 08:22:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234955AbiGVIWZ (ORCPT ); Fri, 22 Jul 2022 04:22:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49030 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234956AbiGVIWW (ORCPT ); Fri, 22 Jul 2022 04:22:22 -0400 Received: from mail-m973.mail.163.com (mail-m973.mail.163.com [123.126.97.3]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id A30749E2A8; Fri, 22 Jul 2022 01:22:20 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=163.com; s=s110527; h=From:Subject:Date:Message-Id:MIME-Version; bh=jT8xe TD2gI4EzRHhvnNsYVU4bZ3vev/hiB/gq6Vqy48=; b=drJmURO5QCePd0ZjqcF3V BbMNClINUkt5AQLtJPIhlN+GbTphU0hBTVEXEeiklCQqQX4Kl0+fpqoTHmW+wvcL T+jWpHDsQuOxpTWfONUUZZzqkBjFuRNy25JKPPoyVRRSJXRAkI3P1J736AbTfXOR 22SHlPJXmXiBUd/55CTXso= Received: from localhost.localdomain (unknown [123.112.69.106]) by smtp3 (Coremail) with SMTP id G9xpCgDnRmMHXtpiTpGIQg--.59076S4; Fri, 22 Jul 2022 16:21:44 +0800 (CST) From: Jianglei Nie To: jejb@linux.ibm.com, jarkko@kernel.org, zohar@linux.ibm.com, dhowells@redhat.com, jmorris@namei.org, serge@hallyn.com Cc: linux-integrity@vger.kernel.org, keyrings@vger.kernel.org, linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org, Jianglei Nie Subject: [PATCH v3] KEYS: trusted: Fix memory leak in tpm2_key_encode() Date: Fri, 22 Jul 2022 16:21:25 +0800 Message-Id: <20220722082125.2526529-1-niejianglei2021@163.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: References: MIME-Version: 1.0 X-CM-TRANSID: G9xpCgDnRmMHXtpiTpGIQg--.59076S4 X-Coremail-Antispam: 1Uf129KBjvJXoWxZr4UGF4DAw43Zr17Zr4DXFb_yoW5Ww1fpF W3KF1jqrWavry7AryxAF4Sv3WSkw1rtFW7KwsFq397GasxJFsxtFy7Ar4Ygr17AFWSqw15 ZFWqvFWUuFZFqrUanT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDUYxBIdaVFxhVjvjDU0xZFpf9x0zR4SoAUUUUU= X-Originating-IP: [123.112.69.106] X-CM-SenderInfo: xqlhyxxdqjzvrlsqjii6rwjhhfrp/1tbiWxlGjGI0VjNM6gAAsd Precedence: bulk List-ID: tpm2_key_encode() allocates a memory chunk from scratch with kmalloc(), but it is never freed, which leads to a memory leak. Free the memory chunk with kfree() in the return path. Fixes: f2219745250f ("security: keys: trusted: use ASN.1 TPM2 key format for the blobs") Signed-off-by: Jianglei Nie --- security/keys/trusted-keys/trusted_tpm2.c | 33 ++++++++++++++++------- 1 file changed, 23 insertions(+), 10 deletions(-) diff --git a/security/keys/trusted-keys/trusted_tpm2.c b/security/keys/trusted-keys/trusted_tpm2.c index 2b2c8eb258d5..eb25c784b5c3 100644 --- a/security/keys/trusted-keys/trusted_tpm2.c +++ b/security/keys/trusted-keys/trusted_tpm2.c @@ -32,8 +32,13 @@ static int tpm2_key_encode(struct trusted_key_payload *payload, struct trusted_key_options *options, u8 *src, u32 len) { + int ret; const int SCRATCH_SIZE = PAGE_SIZE; - u8 *scratch = kmalloc(SCRATCH_SIZE, GFP_KERNEL); + u8 *scratch; + + scratch = kmalloc(SCRATCH_SIZE, GFP_KERNEL); + if (!scratch) + return -ENOMEM; u8 *work = scratch, *work1; u8 *end_work = scratch + SCRATCH_SIZE; u8 *priv, *pub; @@ -47,9 +52,6 @@ static int tpm2_key_encode(struct trusted_key_payload *payload, pub_len = get_unaligned_be16(src) + 2; pub = src; - if (!scratch) - return -ENOMEM; - work = asn1_encode_oid(work, end_work, tpm2key_oid, asn1_oid_len(tpm2key_oid)); @@ -57,8 +59,10 @@ static int tpm2_key_encode(struct trusted_key_payload *payload, unsigned char bool[3], *w = bool; /* tag 0 is emptyAuth */ w = asn1_encode_boolean(w, w + sizeof(bool), true); - if (WARN(IS_ERR(w), "BUG: Boolean failed to encode")) - return PTR_ERR(w); + if (WARN(IS_ERR(w), "BUG: Boolean failed to encode")) { + ret = PTR_ERR(w); + goto err; + } work = asn1_encode_tag(work, end_work, 0, bool, w - bool); } @@ -69,8 +73,10 @@ static int tpm2_key_encode(struct trusted_key_payload *payload, * trigger, so if it does there's something nefarious going on */ if (WARN(work - scratch + pub_len + priv_len + 14 > SCRATCH_SIZE, - "BUG: scratch buffer is too small")) - return -EINVAL; + "BUG: scratch buffer is too small")) { + ret = -EINVAL; + goto err; + } work = asn1_encode_integer(work, end_work, options->keyhandle); work = asn1_encode_octet_string(work, end_work, pub, pub_len); @@ -79,10 +85,17 @@ static int tpm2_key_encode(struct trusted_key_payload *payload, work1 = payload->blob; work1 = asn1_encode_sequence(work1, work1 + sizeof(payload->blob), scratch, work - scratch); - if (WARN(IS_ERR(work1), "BUG: ASN.1 encoder failed")) - return PTR_ERR(work1); + if (WARN(IS_ERR(work1), "BUG: ASN.1 encoder failed")) { + ret = PTR_ERR(work1); + goto err; + } + kfree(scratch); return work1 - payload->blob; + +err: + kfree(scratch); + return ret; } struct tpm2_key_context {