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 2C396CE79CE for ; Wed, 20 Sep 2023 12:04:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235134AbjITMER (ORCPT ); Wed, 20 Sep 2023 08:04:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43904 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235137AbjITMEQ (ORCPT ); Wed, 20 Sep 2023 08:04:16 -0400 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B523092 for ; Wed, 20 Sep 2023 05:04:10 -0700 (PDT) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 09A1BC433C7; Wed, 20 Sep 2023 12:04:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1695211450; bh=LqP3BvptvtgQ3PNJPC8+91f0V4FnJX34pOp9eNDaxYs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=QklwfMD5dEOk/qj5A/zM4E4nKe4ydWCg04z6UsGeme7Bn4oGVCeLKI9poFixhtp7m UQrbZBico/7Ve270UEeH5STA/fzkdRlUH10T/djx/VoGOaCGpY9JjR+/BcYnbtk5Th BXFta23mp0CNyavBxh0v5cvvgDyJN67ag4l1PHB8= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Eric Dumazet , David Laight , Kyle Zeng , Simon Horman , "David S. Miller" Subject: [PATCH 4.14 097/186] igmp: limit igmpv3_newpack() packet size to IP_MAX_MTU Date: Wed, 20 Sep 2023 13:30:00 +0200 Message-ID: <20230920112840.468724448@linuxfoundation.org> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20230920112836.799946261@linuxfoundation.org> References: <20230920112836.799946261@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Eric Dumazet commit c3b704d4a4a265660e665df51b129e8425216ed1 upstream. This is a follow up of commit 915d975b2ffa ("net: deal with integer overflows in kmalloc_reserve()") based on David Laight feedback. Back in 2010, I failed to realize malicious users could set dev->mtu to arbitrary values. This mtu has been since limited to 0x7fffffff but regardless of how big dev->mtu is, it makes no sense for igmpv3_newpack() to allocate more than IP_MAX_MTU and risk various skb fields overflows. Fixes: 57e1ab6eaddc ("igmp: refine skb allocations") Link: https://lore.kernel.org/netdev/d273628df80f45428e739274ab9ecb72@AcuMS.aculab.com/ Signed-off-by: Eric Dumazet Reported-by: David Laight Cc: Kyle Zeng Reviewed-by: Simon Horman Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/ipv4/igmp.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/net/ipv4/igmp.c +++ b/net/ipv4/igmp.c @@ -360,8 +360,9 @@ static struct sk_buff *igmpv3_newpack(st struct flowi4 fl4; int hlen = LL_RESERVED_SPACE(dev); int tlen = dev->needed_tailroom; - unsigned int size = mtu; + unsigned int size; + size = min(mtu, IP_MAX_MTU); while (1) { skb = alloc_skb(size + hlen + tlen, GFP_ATOMIC | __GFP_NOWARN);