From patchwork Thu Dec 8 16:46:10 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Roberto Sassu X-Patchwork-Id: 13068618 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 3D926C10F1E for ; Thu, 8 Dec 2022 16:41:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229993AbiLHQqu (ORCPT ); Thu, 8 Dec 2022 11:46:50 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52442 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229646AbiLHQqu (ORCPT ); Thu, 8 Dec 2022 11:46:50 -0500 Received: from frasgout13.his.huawei.com (frasgout13.his.huawei.com [14.137.139.46]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E4005AD9B9; Thu, 8 Dec 2022 08:46:47 -0800 (PST) Received: from mail02.huawei.com (unknown [172.18.147.228]) by frasgout13.his.huawei.com (SkyGuard) with ESMTP id 4NSfy10j7pz9xG9q; Fri, 9 Dec 2022 00:39:37 +0800 (CST) Received: from huaweicloud.com (unknown [10.204.63.22]) by APP1 (Coremail) with SMTP id LxC2BwDHs3DWFJJjUyvOAA--.59467S2; Thu, 08 Dec 2022 17:46:23 +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] KEYS: asymmetric: Make a copy of sig and digest in vmalloced stack Date: Thu, 8 Dec 2022 17:46:10 +0100 Message-Id: <20221208164610.867747-1-roberto.sassu@huaweicloud.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 X-CM-TRANSID: LxC2BwDHs3DWFJJjUyvOAA--.59467S2 X-Coremail-Antispam: 1UD129KBjvJXoWxJF4xCry8tF4DCr43Kr4fuFg_yoW5uFWkpa 95Wr15tryUGr1Ik3y3C3WxK345Aw4vkr17Ww4fZw45CFsxXrW8C3yIva13WFyfJrykXFWx trWvqws8uF1UXaDanT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUvFb4IE77IF4wAFF20E14v26ryj6rWUM7CY07I20VC2zVCF04k2 6cxKx2IYs7xG6rWj6s0DM7CIcVAFz4kK6r1j6r18M28lY4IEw2IIxxk0rwA2F7IY1VAKz4 vEj48ve4kI8wA2z4x0Y4vE2Ix0cI8IcVAFwI0_Jr0_JF4l84ACjcxK6xIIjxv20xvEc7Cj xVAFwI0_Gr0_Cr1l84ACjcxK6I8E87Iv67AKxVW8JVWxJwA2z4x0Y4vEx4A2jsIEc7CjxV AFwI0_Gr0_Gr1UM2AIxVAIcxkEcVAq07x20xvEncxIr21l5I8CrVACY4xI64kE6c02F40E x7xfMcIj6xIIjxv20xvE14v26r106r15McIj6I8E87Iv67AKxVWUJVW8JwAm72CE4IkC6x 0Yz7v_Jr0_Gr1lF7xvr2IYc2Ij64vIr41lFIxGxcIEc7CjxVA2Y2ka0xkIwI1lc7CjxVAa w2AFwI0_GFv_Wryl42xK82IYc2Ij64vIr41l4I8I3I0E4IkC6x0Yz7v_Jr0_Gr1lx2IqxV Aqx4xG67AKxVWUJVWUGwC20s026x8GjcxK67AKxVWUGVWUWwC2zVAF1VAY17CE14v26r4a 6rW5MIIYrxkI7VAKI48JMIIF0xvE2Ix0cI8IcVAFwI0_Jr0_JF4lIxAIcVC0I7IYx2IY6x kF7I0E14v26r4j6F4UMIIF0xvE42xK8VAvwI8IcIk0rVW8JVW3JwCI42IY6I8E87Iv67AK xVWUJVW8JwCI42IY6I8E87Iv6xkF7I0E14v26r4j6r4UJbIYCTnIWIevJa73UjIFyTuYvj xUxo7KDUUUU X-CM-SenderInfo: purev21wro2thvvxqx5xdzvxpfor3voofrz/1tbiAgAABF1jj4JxzwAAsL X-CFilter-Loop: Reflected Precedence: bulk List-ID: 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. Check if the signature and digest passed to public_key_verify_signature() are in the linear mapping area and, for those which are not, make a copy in the linear mapping area with kmalloc() and adjust the pointer passed to sg_set_buf(). Reuse the existing kmalloc() and increase the allocation size as needed. Minimize the number of copies with the compile-time check of CONFIG_VMAP_STACK and with the run-time check virt_addr_valid(). 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, 34 insertions(+), 5 deletions(-) diff --git a/crypto/asymmetric_keys/public_key.c b/crypto/asymmetric_keys/public_key.c index 2f8352e88860..307799ffbc3e 100644 --- a/crypto/asymmetric_keys/public_key.c +++ b/crypto/asymmetric_keys/public_key.c @@ -363,7 +363,8 @@ 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; - int ret; + char *sig_s, *digest; + int ret, verif_bundle_len; pr_devel("==>%s()\n", __func__); @@ -400,8 +401,21 @@ 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); + verif_bundle_len = pkey->keylen + sizeof(u32) * 2 + pkey->paramlen; + + sig_s = sig->s; + digest = sig->digest; + + if (IS_ENABLED(CONFIG_VMAP_STACK)) { + if (!virt_addr_valid(sig_s)) + verif_bundle_len += sig->s_size; + + if (!virt_addr_valid(digest)) + verif_bundle_len += sig->digest_size; + } + + /* key points to a buffer which could contain the sig and digest too. */ + key = kmalloc(verif_bundle_len, GFP_KERNEL); if (!key) goto error_free_req; @@ -424,9 +438,24 @@ int public_key_verify_signature(const struct public_key *pkey, goto error_free_key; } + if (IS_ENABLED(CONFIG_VMAP_STACK)) { + ptr += pkey->paramlen; + + if (!virt_addr_valid(sig_s)) { + sig_s = ptr; + memcpy(sig_s, sig->s, sig->s_size); + ptr += sig->s_size; + } + + if (!virt_addr_valid(digest)) { + digest = ptr; + memcpy(digest, 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); + sg_set_buf(&src_sg[0], sig_s, sig->s_size); + sg_set_buf(&src_sg[1], digest, sig->digest_size); akcipher_request_set_crypt(req, src_sg, NULL, sig->s_size, sig->digest_size); crypto_init_wait(&cwait);