From patchwork Mon Mar 14 11:53:22 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 551321 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 93DDFC433EF for ; Mon, 14 Mar 2022 12:10:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240716AbiCNMLt (ORCPT ); Mon, 14 Mar 2022 08:11:49 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33616 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241351AbiCNMIi (ORCPT ); Mon, 14 Mar 2022 08:08:38 -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 82BCC4C439; Mon, 14 Mar 2022 05:05:01 -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 04E8B612FF; Mon, 14 Mar 2022 12:05:01 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 36201C36AE2; Mon, 14 Mar 2022 12:04:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1647259500; bh=RsFZTWnfjmpT6i3ems5I0UMcIWdeQ2t770YuUzve0og=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=AI2ClrVzUm7PoJ+nbbAVOgtfO77fOOnlikKtpcLhjfe9IVnFppojHJ6t2BDWZvZlw f1gWAjI0mWudXl3p17SVPW+CWi93xcuikiXsm9iXI1cODZIhbTb0f9YDI6sLVosxm8 9yNEfNX82P0w0vV7WS2Jbqa8Vu79/f9BLN43UmKo= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, valis , Steffen Klassert , Sasha Levin Subject: [PATCH 5.15 020/110] esp: Fix possible buffer overflow in ESP transformation Date: Mon, 14 Mar 2022 12:53:22 +0100 Message-Id: <20220314112743.599549873@linuxfoundation.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220314112743.029192918@linuxfoundation.org> References: <20220314112743.029192918@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Steffen Klassert [ Upstream commit ebe48d368e97d007bfeb76fcb065d6cfc4c96645 ] 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: Sasha Levin --- include/net/esp.h | 2 ++ net/ipv4/esp4.c | 5 +++++ net/ipv6/esp6.c | 5 +++++ 3 files changed, 12 insertions(+) diff --git a/include/net/esp.h b/include/net/esp.h index 9c5637d41d95..90cd02ff77ef 100644 --- 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) diff --git a/net/ipv4/esp4.c b/net/ipv4/esp4.c index e1b1d080e908..70e6c87fbe3d 100644 --- a/net/ipv4/esp4.c +++ b/net/ipv4/esp4.c @@ -446,6 +446,7 @@ 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) { @@ -455,6 +456,10 @@ 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) + goto cow; + if (!skb_cloned(skb)) { if (tailen <= skb_tailroom(skb)) { nfrags = 1; diff --git a/net/ipv6/esp6.c b/net/ipv6/esp6.c index 883b53fd7846..b7b573085bd5 100644 --- a/net/ipv6/esp6.c +++ b/net/ipv6/esp6.c @@ -483,6 +483,7 @@ 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); @@ -491,6 +492,10 @@ 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) + goto cow; + if (!skb_cloned(skb)) { if (tailen <= skb_tailroom(skb)) { nfrags = 1;