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 F1AF6C4167B for ; Mon, 21 Mar 2022 14:12:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1351759AbiCUOLm (ORCPT ); Mon, 21 Mar 2022 10:11:42 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38006 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1348565AbiCUOCj (ORCPT ); Mon, 21 Mar 2022 10:02:39 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E7F5CA27D3; Mon, 21 Mar 2022 06:59:34 -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 dfw.source.kernel.org (Postfix) with ESMTPS id B386B61325; Mon, 21 Mar 2022 13:59:28 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B9938C340ED; Mon, 21 Mar 2022 13:59:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1647871168; bh=WbAXIMIpSRb7OSyInJWIlEk1e63sTaThqozBnDrl2dY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=u02wL1SW39FzXRYbI6Wr4VNYBTOOjMJFXrUt23gT3ZDI3RVepUxUI0zW1Vxq2u+Lm u9fiQmv0GVCry/THldhali7hCktgIj+LbIgy1fxP66cCfjMSu2/Wdy8BQCGxo61Zv4 nr47/p4qZH5xVxu65ls4I8Ud48tMpB8Qezomftx0= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, valis , Steffen Klassert , Tadeusz Struk Subject: [PATCH 5.10 29/30] esp: Fix possible buffer overflow in ESP transformation Date: Mon, 21 Mar 2022 14:52:59 +0100 Message-Id: <20220321133220.490047170@linuxfoundation.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220321133219.643490199@linuxfoundation.org> References: <20220321133219.643490199@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Steffen Klassert commit ebe48d368e97d007bfeb76fcb065d6cfc4c96645 upstream. The maximum message size that can be send is bigger than the maximum site that skb_page_frag_refill can allocate. So it is possible to write beyond the allocated buffer. Fix this by doing a fallback to COW in that case. v2: Avoid get get_order() costs as suggested by Linus Torvalds. Fixes: cac2661c53f3 ("esp4: Avoid skb_cow_data whenever possible") Fixes: 03e2a30f6a27 ("esp6: Avoid skb_cow_data whenever possible") Reported-by: valis Signed-off-by: Steffen Klassert Signed-off-by: Tadeusz Struk Signed-off-by: Greg Kroah-Hartman --- include/net/esp.h | 2 ++ include/net/sock.h | 1 + net/ipv4/esp4.c | 5 +++++ net/ipv6/esp6.c | 5 +++++ 4 files changed, 13 insertions(+) --- a/include/net/esp.h +++ b/include/net/esp.h @@ -4,6 +4,8 @@ #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/include/net/sock.h +++ b/include/net/sock.h @@ -2670,6 +2670,7 @@ extern int sysctl_optmem_max; extern __u32 sysctl_wmem_default; extern __u32 sysctl_rmem_default; +#define SKB_FRAG_PAGE_ORDER get_order(32768) DECLARE_STATIC_KEY_FALSE(net_high_order_alloc_disable_key); static inline int sk_get_wmem0(const struct sock *sk, const struct proto *proto) --- a/net/ipv4/esp4.c +++ b/net/ipv4/esp4.c @@ -448,6 +448,7 @@ 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 TCP/UDP Encapsulation */ if (x->encap) { @@ -457,6 +458,10 @@ 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) + goto cow; + if (!skb_cloned(skb)) { if (tailen <= skb_tailroom(skb)) { nfrags = 1; --- a/net/ipv6/esp6.c +++ b/net/ipv6/esp6.c @@ -483,6 +483,7 @@ int esp6_output_head(struct xfrm_state * 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); @@ -491,6 +492,10 @@ int esp6_output_head(struct xfrm_state * return err; } + allocsz = ALIGN(skb->data_len + tailen, L1_CACHE_BYTES); + if (allocsz > ESP_SKB_FRAG_MAXSIZE) + goto cow; + if (!skb_cloned(skb)) { if (tailen <= skb_tailroom(skb)) { nfrags = 1;