From mboxrd@z Thu Jan 1 00:00:00 1970 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 DEEDBC10F1B for ; Tue, 27 Dec 2022 10:53:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229751AbiL0Kwm (ORCPT ); Tue, 27 Dec 2022 05:52:42 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51878 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231403AbiL0Kwj (ORCPT ); Tue, 27 Dec 2022 05:52:39 -0500 Received: from frasgout11.his.huawei.com (frasgout11.his.huawei.com [14.137.139.23]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3B6471E3; Tue, 27 Dec 2022 02:52:37 -0800 (PST) Received: from mail02.huawei.com (unknown [172.18.147.227]) by frasgout11.his.huawei.com (SkyGuard) with ESMTP id 4NhBB91s4Sz9xHvM; Tue, 27 Dec 2022 18:45:05 +0800 (CST) Received: from [10.48.132.132] (unknown [10.48.132.132]) by APP1 (Coremail) with SMTP id LxC2BwAXnAdPzqpjpWtJAA--.20242S2; Tue, 27 Dec 2022 11:52:13 +0100 (CET) Message-ID: Date: Tue, 27 Dec 2022 11:51:52 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101 Thunderbird/102.6.0 Subject: Re: [PATCH v4 2/2] KEYS: asymmetric: Copy sig and digest in public_key_verify_signature() 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, ebiggers@kernel.org 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 References: <20221227094632.2797203-1-roberto.sassu@huaweicloud.com> <20221227094632.2797203-2-roberto.sassu@huaweicloud.com> Content-Language: en-US In-Reply-To: <20221227094632.2797203-2-roberto.sassu@huaweicloud.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-CM-TRANSID: LxC2BwAXnAdPzqpjpWtJAA--.20242S2 X-Coremail-Antispam: 1UD129KBjvJXoWxAFWfuF18KFWfWr48GF17KFg_yoWrAw4xpF Z8WrWUKry5Jrn2krZxCa18t3yrA3y8A3Wagw4fJw13CrnxZrWkGry29r47Wry7JrykXry8 tr4kWws5Wr1DXaDanT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUv2b4IE77IF4wAFF20E14v26ryj6rWUM7CY07I20VC2zVCF04k2 6cxKx2IYs7xG6rWj6s0DM7CIcVAFz4kK6r1j6r18M28lY4IEw2IIxxk0rwA2F7IY1VAKz4 vEj48ve4kI8wA2z4x0Y4vE2Ix0cI8IcVAFwI0_Jr0_JF4l84ACjcxK6xIIjxv20xvEc7Cj xVAFwI0_Gr0_Cr1l84ACjcxK6I8E87Iv67AKxVW8JVWxJwA2z4x0Y4vEx4A2jsIEc7CjxV AFwI0_Gr0_Gr1UM2AIxVAIcxkEcVAq07x20xvEncxIr21l5I8CrVACY4xI64kE6c02F40E x7xfMcIj6xIIjxv20xvE14v26r1j6r18McIj6I8E87Iv67AKxVWUJVW8JwAm72CE4IkC6x 0Yz7v_Jr0_Gr1lF7xvr2IY64vIr41lFIxGxcIEc7CjxVA2Y2ka0xkIwI1lc7I2V7IY0VAS 07AlzVAYIcxG8wCF04k20xvY0x0EwIxGrwCFx2IqxVCFs4IE7xkEbVWUJVW8JwC20s026c 02F40E14v26r1j6r18MI8I3I0E7480Y4vE14v26r106r1rMI8E67AF67kF1VAFwI0_GFv_ WrylIxkGc2Ij64vIr41lIxAIcVC0I7IYx2IY67AKxVWUJVWUCwCI42IY6xIIjxv20xvEc7 CjxVAFwI0_Gr0_Cr1lIxAIcVCF04k26cxKx2IYs7xG6rW3Jr0E3s1lIxAIcVC2z280aVAF wI0_Jr0_Gr1lIxAIcVC2z280aVCY1x0267AKxVW8JVW8JrUvcSsGvfC2KfnxnUUI43ZEXa 7IU13rcDUUUUU== X-CM-SenderInfo: purev21wro2thvvxqx5xdzvxpfor3voofrz/1tbiAgATBF1jj4MKCgACsl X-CFilter-Loop: Reflected Precedence: bulk List-ID: On 12/27/2022 10:46 AM, Roberto Sassu wrote: > 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 | 39 ++++++++++++++++------------- > 1 file changed, 22 insertions(+), 17 deletions(-) > > diff --git a/crypto/asymmetric_keys/public_key.c b/crypto/asymmetric_keys/public_key.c > index 2f8352e88860..a479e32cb280 100644 > --- a/crypto/asymmetric_keys/public_key.c > +++ b/crypto/asymmetric_keys/public_key.c > @@ -360,9 +360,10 @@ int public_key_verify_signature(const struct public_key *pkey, > struct crypto_wait cwait; > struct crypto_akcipher *tfm; > struct akcipher_request *req; > - struct scatterlist src_sg[2]; > + struct scatterlist src_sg; > char alg_name[CRYPTO_MAX_ALG_NAME]; > - char *key, *ptr; > + char *buf, *ptr; > + size_t buf_len; > int ret; > > pr_devel("==>%s()\n", __func__); > @@ -400,34 +401,38 @@ 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); > - if (!key) > + buf_len = max_t(size_t, pkey->keylen + sizeof(u32) * 2 + pkey->paramlen, > + sig->s_size + sig->digest_size); > + > + buf = kmalloc(buf_len, GFP_KERNEL); > + if (!buf) > goto error_free_req; > > - memcpy(key, pkey->key, pkey->keylen); > - ptr = key + pkey->keylen; > + memcpy(buf, pkey->key, pkey->keylen); > + ptr = buf + pkey->keylen; > ptr = pkey_pack_u32(ptr, pkey->algo); > ptr = pkey_pack_u32(ptr, pkey->paramlen); > memcpy(ptr, pkey->params, pkey->paramlen); > > if (pkey->key_is_private) > - ret = crypto_akcipher_set_priv_key(tfm, key, pkey->keylen); > + ret = crypto_akcipher_set_priv_key(tfm, buf, pkey->keylen); > else > - ret = crypto_akcipher_set_pub_key(tfm, key, pkey->keylen); > + ret = crypto_akcipher_set_pub_key(tfm, buf, pkey->keylen); > if (ret) > - goto error_free_key; > + goto error_free_buf; > > if (strcmp(pkey->pkey_algo, "sm2") == 0 && sig->data_size) { > ret = cert_sig_digest_update(sig, tfm); > if (ret) > - goto error_free_key; > + goto error_free_buf; > } > > - 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); > - akcipher_request_set_crypt(req, src_sg, NULL, sig->s_size, > + memcpy(buf, sig->s, sig->s_size); > + memcpy(buf + sig->s_size, sig->digest, sig->digest_size); > + > + sg_init_table(&src_sg, 1); > + sg_set_buf(&src_sg, buf, sig->s_size + sig->digest_size); Ops, didn't commit the changes. Will send a new version soon. Roberto > + akcipher_request_set_crypt(req, &src_sg, NULL, sig->s_size, > sig->digest_size); > crypto_init_wait(&cwait); > akcipher_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG | > @@ -435,8 +440,8 @@ int public_key_verify_signature(const struct public_key *pkey, > crypto_req_done, &cwait); > ret = crypto_wait_req(crypto_akcipher_verify(req), &cwait); > > -error_free_key: > - kfree(key); > +error_free_buf: > + kfree(buf); > error_free_req: > akcipher_request_free(req); > error_free_tfm: