From patchwork Tue Mar 11 10:20:31 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Herbert Xu X-Patchwork-Id: 14011449 X-Patchwork-Delegate: herbert@gondor.apana.org.au Received: from abb.hmeau.com (abb.hmeau.com [144.6.53.87]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4CB1422FAC3 for ; Tue, 11 Mar 2025 10:20:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=144.6.53.87 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741688437; cv=none; b=V4ub95pkS8wZqS9+D7pDlZsiXrdwaiD8Ovg2+4S+9InBWkcjfNHHSKjI653H2VbGvCDaoeYDS1CUPHR2pJEL0qnAo6Zic0TXbpF/eXdWgoKczIdzVcGOO72tcukDPQ4GoANquJVfjDW0vpLhmMjSdFyUY44hwrD1HD+KtKbcfAk= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741688437; c=relaxed/simple; bh=oqAl44/16ogrton1crAj6AdPxyrfydmopBW4he0VS8s=; h=Date:Message-Id:In-Reply-To:References:From:Subject:To; b=OkbWLro9WWvcczf3Fe4W9/U/RJz8VzT/t5xerSW5HlfD5zlJ8jycuOM8UI2+2/ghWcrxKw8jGlwOK1NRu0W812FCo/xcucUOkz4O+0YVV6xef80Hekx1AjFF1CuvAN0HmNZ8tsN3ogNQrB/xlYnTwiRavgQsKNQ9LWEvrAPEj6s= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=gondor.apana.org.au; spf=pass smtp.mailfrom=gondor.apana.org.au; dkim=pass (2048-bit key) header.d=hmeau.com header.i=@hmeau.com header.b=TaKlz7cf; arc=none smtp.client-ip=144.6.53.87 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=gondor.apana.org.au Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gondor.apana.org.au Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=hmeau.com header.i=@hmeau.com header.b="TaKlz7cf" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=hmeau.com; s=formenos; h=To:Subject:From:References:In-Reply-To:Message-Id:Date:Sender: Reply-To:Cc:MIME-Version:Content-Type:Content-Transfer-Encoding:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=mwgnhhyUokXHbzqZLKg4QW/Np8o0K+acOG2Mbe5W3FU=; b=TaKlz7cfDjDxoGihUQjPvQA+B3 srlyHrzbOwUAJMS4iaa8vvKuiRxLj/msSOCRn7hlWTi+DHReU8i9ktckllbcpw5+eGAj1JvWg9vnV Iete/NHH488mXU4TA2v5cYq4g+8MGC+OVgFYTAwWAeL5sSYYz1eqrf2WsV2XVWNtKz/hC7D8QRF2F mUDtLxNKlTN9s9A2d46rzwAH5q2hddvBwStecDxT0TrBOeBjAo4chHypvJLK0sDlP+WzxRwvK6fRl dSQivwpoEayggiLy0wvxUEJSAl/W6JGLruGWA+YncZyxn/iRroQyck4smWEEymIKzb5Q0c8BafrkE Ua613JyQ==; Received: from loth.rohan.me.apana.org.au ([192.168.167.2]) by formenos.hmeau.com with smtp (Exim 4.96 #2 (Debian)) id 1trwit-005YUn-1p; Tue, 11 Mar 2025 18:20:32 +0800 Received: by loth.rohan.me.apana.org.au (sSMTP sendmail emulation); Tue, 11 Mar 2025 18:20:31 +0800 Date: Tue, 11 Mar 2025 18:20:31 +0800 Message-Id: In-Reply-To: References: From: Herbert Xu Subject: [PATCH 2/3] crypto: hash - Use nth_page instead of doing it by hand To: Linux Crypto Mailing List Precedence: bulk X-Mailing-List: linux-crypto@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Use nth_page instead of adding n to the page pointer. This also fixes a real bug in shash_ahash_digest where the the check for continguous hash data may be incorrect in the presence of highmem. This could result in an incorrect hash or worse. Fixes: 5f7082ed4f48 ("crypto: hash - Export shash through hash") Signed-off-by: Herbert Xu --- crypto/ahash.c | 38 +++++++++++++++++++++++++------------- 1 file changed, 25 insertions(+), 13 deletions(-) diff --git a/crypto/ahash.c b/crypto/ahash.c index 9c26175c21a8..75d642897e36 100644 --- a/crypto/ahash.c +++ b/crypto/ahash.c @@ -16,6 +16,7 @@ #include #include #include +#include #include #include #include @@ -79,7 +80,7 @@ static int hash_walk_new_entry(struct crypto_hash_walk *walk) sg = walk->sg; walk->offset = sg->offset; - walk->pg = sg_page(walk->sg) + (walk->offset >> PAGE_SHIFT); + walk->pg = nth_page(sg_page(walk->sg), walk->offset >> PAGE_SHIFT); walk->offset = offset_in_page(walk->offset); walk->entrylen = sg->length; @@ -201,25 +202,36 @@ int shash_ahash_digest(struct ahash_request *req, struct shash_desc *desc) unsigned int nbytes = req->nbytes; struct scatterlist *sg; unsigned int offset; + struct page *page; + void *data; int err; - if (ahash_request_isvirt(req)) + if (!nbytes || ahash_request_isvirt(req)) return crypto_shash_digest(desc, req->svirt, nbytes, req->result); - if (nbytes && - (sg = req->src, offset = sg->offset, - nbytes <= min(sg->length, ((unsigned int)(PAGE_SIZE)) - offset))) { - void *data; + sg = req->src; + if (nbytes > sg->length) + return crypto_shash_init(desc) ?: + shash_ahash_finup(req, desc); - data = kmap_local_page(sg_page(sg)); - err = crypto_shash_digest(desc, data + offset, nbytes, - req->result); - kunmap_local(data); - } else - err = crypto_shash_init(desc) ?: - shash_ahash_finup(req, desc); + page = sg_page(sg); + offset = sg->offset; + page = nth_page(page, offset >> PAGE_SHIFT); + offset = offset_in_page(offset); + if (!IS_ENABLED(CONFIG_HIGHMEM)) + return crypto_shash_digest(desc, page_address(page) + offset, + nbytes, req->result); + + if (nbytes > (unsigned int)PAGE_SIZE - offset) + return crypto_shash_init(desc) ?: + shash_ahash_finup(req, desc); + + data = kmap_local_page(page); + err = crypto_shash_digest(desc, data + offset, nbytes, + req->result); + kunmap_local(data); return err; } EXPORT_SYMBOL_GPL(shash_ahash_digest);