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 CD3BAC43334 for ; Mon, 11 Jul 2022 09:08:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230432AbiGKJI2 (ORCPT ); Mon, 11 Jul 2022 05:08:28 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47204 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231195AbiGKJH5 (ORCPT ); Mon, 11 Jul 2022 05:07:57 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CB6DC2497E; Mon, 11 Jul 2022 02:07:34 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 0163CB80D2C; Mon, 11 Jul 2022 09:07:33 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6C1AAC341CA; Mon, 11 Jul 2022 09:07:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1657530451; bh=41osInqy4wOa4+2t1XImaRvNj+PBf+rtJFHd/tCOres=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Lmb0JZlxpwT+seIibXmkiL2t6lrOZ5T/uqRPfsiXfsE5ObdCDQmzBON3FDvD0/D1t A3d27dOIN/pBWsacsKuSoEmLSli7raawFDOevUvOE1j2aNpQCOzSdnz1BPPUHDMj+m wdPwEMLg5z4vMOHvUcBZGGeVQPlfEg52atXpuS6U= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Sabrina Dubroca , Steffen Klassert Subject: [PATCH 4.14 01/17] esp: limit skb_page_frag_refill use to a single page Date: Mon, 11 Jul 2022 11:06:26 +0200 Message-Id: <20220711090536.292670494@linuxfoundation.org> X-Mailer: git-send-email 2.37.0 In-Reply-To: <20220711090536.245939953@linuxfoundation.org> References: <20220711090536.245939953@linuxfoundation.org> User-Agent: quilt/0.66 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Sabrina Dubroca commit 5bd8baab087dff657e05387aee802e70304cc813 upstream. Commit ebe48d368e97 ("esp: Fix possible buffer overflow in ESP transformation") tried to fix skb_page_frag_refill usage in ESP by capping allocsize to 32k, but that doesn't completely solve the issue, as skb_page_frag_refill may return a single page. If that happens, we will write out of bounds, despite the check introduced in the previous patch. This patch forces COW in cases where we would end up calling skb_page_frag_refill with a size larger than a page (first in esp_output_head with tailen, then in esp_output_tail with skb->data_len). Fixes: cac2661c53f3 ("esp4: Avoid skb_cow_data whenever possible") Fixes: 03e2a30f6a27 ("esp6: Avoid skb_cow_data whenever possible") Signed-off-by: Sabrina Dubroca Signed-off-by: Steffen Klassert Signed-off-by: Greg Kroah-Hartman --- include/net/esp.h | 2 -- net/ipv4/esp4.c | 5 ++--- net/ipv6/esp6.c | 5 ++--- 3 files changed, 4 insertions(+), 8 deletions(-) --- a/include/net/esp.h +++ b/include/net/esp.h @@ -4,8 +4,6 @@ #include -#define ESP_SKB_FRAG_MAXSIZE (PAGE_SIZE << SKB_FRAG_PAGE_ORDER) - struct ip_esp_hdr; static inline struct ip_esp_hdr *ip_esp_hdr(const struct sk_buff *skb) --- a/net/ipv4/esp4.c +++ b/net/ipv4/esp4.c @@ -257,7 +257,6 @@ int esp_output_head(struct xfrm_state *x struct page *page; struct sk_buff *trailer; int tailen = esp->tailen; - unsigned int allocsz; /* this is non-NULL only with UDP Encapsulation */ if (x->encap) { @@ -267,8 +266,8 @@ int esp_output_head(struct xfrm_state *x return err; } - allocsz = ALIGN(skb->data_len + tailen, L1_CACHE_BYTES); - if (allocsz > ESP_SKB_FRAG_MAXSIZE) + if (ALIGN(tailen, L1_CACHE_BYTES) > PAGE_SIZE || + ALIGN(skb->data_len, L1_CACHE_BYTES) > PAGE_SIZE) goto cow; if (!skb_cloned(skb)) { --- a/net/ipv6/esp6.c +++ b/net/ipv6/esp6.c @@ -223,10 +223,9 @@ int esp6_output_head(struct xfrm_state * struct page *page; struct sk_buff *trailer; int tailen = esp->tailen; - unsigned int allocsz; - allocsz = ALIGN(skb->data_len + tailen, L1_CACHE_BYTES); - if (allocsz > ESP_SKB_FRAG_MAXSIZE) + if (ALIGN(tailen, L1_CACHE_BYTES) > PAGE_SIZE || + ALIGN(skb->data_len, L1_CACHE_BYTES) > PAGE_SIZE) goto cow; if (!skb_cloned(skb)) {