From patchwork Fri Dec 9 15:06:33 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Roberto Sassu X-Patchwork-Id: 13069699 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 6F334C4332F for ; Fri, 9 Dec 2022 15:07:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230133AbiLIPHZ (ORCPT ); Fri, 9 Dec 2022 10:07:25 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56784 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230149AbiLIPHP (ORCPT ); Fri, 9 Dec 2022 10:07:15 -0500 Received: from frasgout12.his.huawei.com (frasgout12.his.huawei.com [14.137.139.154]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AB94E31DC3; Fri, 9 Dec 2022 07:07:13 -0800 (PST) Received: from mail02.huawei.com (unknown [172.18.147.229]) by frasgout12.his.huawei.com (SkyGuard) with ESMTP id 4NTDj50wv1z9v7cV; Fri, 9 Dec 2022 23:00:25 +0800 (CST) Received: from huaweicloud.com (unknown [10.204.63.22]) by APP2 (Coremail) with SMTP id GxC2BwC37PgAT5NjmZfRAA--.1505S2; Fri, 09 Dec 2022 16:06:48 +0100 (CET) From: Roberto Sassu To: dhowells@redhat.com, herbert@gondor.apana.org.au, davem@davemloft.net, zohar@linux.ibm.com, dmitry.kasatkin@gmail.com, paul@paul-moore.com, jmorris@namei.org, serge@hallyn.com Cc: linux-integrity@vger.kernel.org, linux-security-module@vger.kernel.org, keyrings@vger.kernel.org, linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org, Roberto Sassu , stable@vger.kernel.org, Eric Biggers Subject: [PATCH v2] KEYS: asymmetric: Copy sig and digest in public_key_verify_signature() Date: Fri, 9 Dec 2022 16:06:33 +0100 Message-Id: <20221209150633.1033556-1-roberto.sassu@huaweicloud.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 X-CM-TRANSID: GxC2BwC37PgAT5NjmZfRAA--.1505S2 X-Coremail-Antispam: 1UD129KBjvJXoWxJF4xCry8tF47try5uF1UAwb_yoW5Wrykpa n5WrW5tFyUGr1Skry3Aw4Ik34rAw4kJFW2gw4Iyws5uwn8XrZ3C3yIvF43WFyxJrykWryf trWkWw4UuF1UXaDanT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUvab4IE77IF4wAFF20E14v26ryj6rWUM7CY07I20VC2zVCF04k2 6cxKx2IYs7xG6rWj6s0DM7CIcVAFz4kK6r1j6r18M28lY4IEw2IIxxk0rwA2F7IY1VAKz4 vEj48ve4kI8wA2z4x0Y4vE2Ix0cI8IcVAFwI0_Jr0_JF4l84ACjcxK6xIIjxv20xvEc7Cj xVAFwI0_Gr0_Cr1l84ACjcxK6I8E87Iv67AKxVW8JVWxJwA2z4x0Y4vEx4A2jsIEc7CjxV AFwI0_Gr1j6F4UJwAS0I0E0xvYzxvE52x082IY62kv0487Mc02F40EFcxC0VAKzVAqx4xG 6I80ewAv7VC0I7IYx2IY67AKxVWUGVWUXwAv7VC2z280aVAFwI0_Jr0_Gr1lOx8S6xCaFV Cjc4AY6r1j6r4UM4x0Y48IcxkI7VAKI48JM4IIrI8v6xkF7I0E8cxan2IY04v7MxkF7I0E n4kS14v26r4a6rW5MxAIw28IcxkI7VAKI48JMxC20s026xCaFVCjc4AY6r1j6r4UMI8I3I 0E5I8CrVAFwI0_Jr0_Jr4lx2IqxVCjr7xvwVAFwI0_JrI_JrWlx4CE17CEb7AF67AKxVW8 ZVWrXwCIc40Y0x0EwIxGrwCI42IY6xIIjxv20xvE14v26r1j6r1xMIIF0xvE2Ix0cI8IcV CY1x0267AKxVW8JVWxJwCI42IY6xAIw20EY4v20xvaj40_Zr0_Wr1UMIIF0xvEx4A2jsIE 14v26r1j6r4UMIIF0xvEx4A2jsIEc7CjxVAFwI0_Gr1j6F4UJbIYCTnIWIevJa73UjIFyT uYvjxUxo7KDUUUU X-CM-SenderInfo: purev21wro2thvvxqx5xdzvxpfor3voofrz/1tbiAgABBF1jj4J50AACsf X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org From: Roberto Sassu Commit ac4e97abce9b8 ("scatterlist: sg_set_buf() argument must be in linear mapping") checks that both the signature and the digest reside in the linear mapping area. However, more recently commit ba14a194a434c ("fork: Add generic vmalloced stack support"), made it possible to move the stack in the vmalloc area, which is not contiguous, and thus not suitable for sg_set_buf() which needs adjacent pages. Always make a copy of the signature and digest in the same buffer used to store the key and its parameters, and pass them to sg_set_buf(). Prefer it to conditionally doing the copy if necessary, to keep the code simple. The buffer allocated with kmalloc() is in the linear mapping area. Cc: stable@vger.kernel.org # 4.9.x Fixes: ba14a194a434 ("fork: Add generic vmalloced stack support") Link: https://lore.kernel.org/linux-integrity/Y4pIpxbjBdajymBJ@sol.localdomain/ Suggested-by: Eric Biggers Signed-off-by: Roberto Sassu --- crypto/asymmetric_keys/public_key.c | 17 +++++++++++++---- 1 file changed, 13 insertions(+), 4 deletions(-) diff --git a/crypto/asymmetric_keys/public_key.c b/crypto/asymmetric_keys/public_key.c index 2f8352e88860..ccc091119972 100644 --- a/crypto/asymmetric_keys/public_key.c +++ b/crypto/asymmetric_keys/public_key.c @@ -363,6 +363,7 @@ int public_key_verify_signature(const struct public_key *pkey, struct scatterlist src_sg[2]; char alg_name[CRYPTO_MAX_ALG_NAME]; char *key, *ptr; + u32 key_max_len; int ret; pr_devel("==>%s()\n", __func__); @@ -400,8 +401,12 @@ int public_key_verify_signature(const struct public_key *pkey, if (!req) goto error_free_tfm; - key = kmalloc(pkey->keylen + sizeof(u32) * 2 + pkey->paramlen, - GFP_KERNEL); + key_max_len = max_t(u32, + pkey->keylen + sizeof(u32) * 2 + pkey->paramlen, + sig->s_size + sig->digest_size); + + /* key is used to store the sig and digest too. */ + key = kmalloc(key_max_len, GFP_KERNEL); if (!key) goto error_free_req; @@ -424,9 +429,13 @@ int public_key_verify_signature(const struct public_key *pkey, goto error_free_key; } + memcpy(key, sig->s, sig->s_size); + memcpy(key + sig->s_size, sig->digest, sig->digest_size); + sg_init_table(src_sg, 2); - sg_set_buf(&src_sg[0], sig->s, sig->s_size); - sg_set_buf(&src_sg[1], sig->digest, sig->digest_size); + /* Cannot use one scatterlist. The first needs to be s->s_size long. */ + sg_set_buf(&src_sg[0], key, sig->s_size); + sg_set_buf(&src_sg[1], key + sig->s_size, sig->digest_size); akcipher_request_set_crypt(req, src_sg, NULL, sig->s_size, sig->digest_size); crypto_init_wait(&cwait);