From patchwork Tue Apr 26 08:20:44 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 566657 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 46867C433EF for ; Tue, 26 Apr 2022 08:37:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1345153AbiDZIks (ORCPT ); Tue, 26 Apr 2022 04:40:48 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33638 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1345855AbiDZIjj (ORCPT ); Tue, 26 Apr 2022 04:39:39 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A625A793B5; Tue, 26 Apr 2022 01:32:10 -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 dfw.source.kernel.org (Postfix) with ESMTPS id 2DD0361864; Tue, 26 Apr 2022 08:32:10 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1EC76C385A0; Tue, 26 Apr 2022 08:32:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1650961929; bh=4LPqaj5Lo0OfNPU9gxZMt0k8k/l1yn/DuS3f4pPqxeo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=BtOTkTUG3vDQslzaFXOqbbMM/TqC/Z0aACS4ihLb0Gja2ilSmHe3WPPK4xvle2SxX is0WaM9ZoMqLN1qvFwsSmMIOsPYak36IGaFzOnj6MMkkEivqbNXwfqwZ5y/QZtmRpF HfXCLnBg1n/ju/i0ObK8yhof1EGScQkCeXwedRg4= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Sabrina Dubroca , Steffen Klassert , Sasha Levin Subject: [PATCH 5.10 16/86] esp: limit skb_page_frag_refill use to a single page Date: Tue, 26 Apr 2022 10:20:44 +0200 Message-Id: <20220426081741.674635373@linuxfoundation.org> X-Mailer: git-send-email 2.36.0 In-Reply-To: <20220426081741.202366502@linuxfoundation.org> References: <20220426081741.202366502@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Sabrina Dubroca [ Upstream commit 5bd8baab087dff657e05387aee802e70304cc813 ] 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: Sasha Levin --- include/net/esp.h | 2 -- net/ipv4/esp4.c | 5 ++--- net/ipv6/esp6.c | 5 ++--- 3 files changed, 4 insertions(+), 8 deletions(-) diff --git a/include/net/esp.h b/include/net/esp.h index 90cd02ff77ef..9c5637d41d95 100644 --- 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) diff --git a/net/ipv4/esp4.c b/net/ipv4/esp4.c index 9aae82145bc1..20d738137841 100644 --- a/net/ipv4/esp4.c +++ b/net/ipv4/esp4.c @@ -448,7 +448,6 @@ int esp_output_head(struct xfrm_state *x, struct sk_buff *skb, struct esp_info * struct page *page; struct sk_buff *trailer; int tailen = esp->tailen; - unsigned int allocsz; /* this is non-NULL only with TCP/UDP Encapsulation */ if (x->encap) { @@ -458,8 +457,8 @@ int esp_output_head(struct xfrm_state *x, struct sk_buff *skb, struct esp_info * 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)) { diff --git a/net/ipv6/esp6.c b/net/ipv6/esp6.c index 20c7bef6829e..cb28f8928f9e 100644 --- a/net/ipv6/esp6.c +++ b/net/ipv6/esp6.c @@ -483,7 +483,6 @@ int esp6_output_head(struct xfrm_state *x, struct sk_buff *skb, struct esp_info struct page *page; struct sk_buff *trailer; int tailen = esp->tailen; - unsigned int allocsz; if (x->encap) { int err = esp6_output_encap(x, skb, esp); @@ -492,8 +491,8 @@ int esp6_output_head(struct xfrm_state *x, struct sk_buff *skb, struct esp_info 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)) {