From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from ganesha.gnumonks.org (ganesha.gnumonks.org [213.95.27.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D8F6317625E; Thu, 15 Aug 2024 08:55:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=213.95.27.120 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723712152; cv=none; b=c6VxOXRTp+heeXXZYEMZao/XVVOSNui2c0+HOzA3oqKKTVbSg+ckJJPWm6uhfc86hWaqHOHGwrb6R3bM1ktg4poIgKH2nPmAFSck1deXedbnDjOZBXiXl8BMTCTVT4hUTuP57kiInaZIhnC7lZvEA2mJnMfJmtmGeOcVmN9Rg4M= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723712152; c=relaxed/simple; bh=6Pa7Piw4vYLO/WuuQnk7QzeAp3aDRW6Q0Ehifw9hFlM=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=SZFIQkC1UhjJkreeflVcIuNa/t1uwo4KwEALCm9TRtE0iugIXyXL8Go86soVicVOmZZY/IOrK99JVcC6RH+jiz73A6wzHVoFw7kR/Z9pnyT16RF1MkJ64PeYK+2Vy0nMjDoS26XViUuUFVsn3Hirr2hy7nVdbVPo7v8ZQTYy2+k= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=netfilter.org; spf=pass smtp.mailfrom=gnumonks.org; arc=none smtp.client-ip=213.95.27.120 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=netfilter.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gnumonks.org Received: from [78.30.37.63] (port=36446 helo=gnumonks.org) by ganesha.gnumonks.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1seWGk-00GrRE-Rj; Thu, 15 Aug 2024 10:55:45 +0200 Date: Thu, 15 Aug 2024 10:55:41 +0200 From: Pablo Neira Ayuso To: icejl Cc: kadlec@netfilter.org, davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, netfilter-devel@vger.kernel.org, coreteam@netfilter.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] netfilter: nfnetlink: fix uninitialized local variable Message-ID: References: <20240815082733.272087-1-icejl0001@gmail.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: X-Spam-Score: -1.9 (-) For the record: https://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf.git/commit/?id=d1a7b382a9d3f0f3e5a80e0be2991c075fa4f618 Fixes: bf2ac490d28c ("netfilter: nfnetlink: Handle ACK flags for batch messages") On Thu, Aug 15, 2024 at 10:32:11AM +0200, Pablo Neira Ayuso wrote: > There is a fix already traveling for this in a pull request. > > On Thu, Aug 15, 2024 at 04:27:33PM +0800, icejl wrote: > > In the nfnetlink_rcv_batch function, an uninitialized local variable > > extack is used, which results in using random stack data as a pointer. > > This pointer is then used to access the data it points to and return > > it as the request status, leading to an information leak. If the stack > > data happens to be an invalid pointer, it can cause a pointer access > > exception, triggering a kernel crash. > > > > Signed-off-by: icejl > > --- > > net/netfilter/nfnetlink.c | 1 + > > 1 file changed, 1 insertion(+) > > > > diff --git a/net/netfilter/nfnetlink.c b/net/netfilter/nfnetlink.c > > index 4abf660c7baf..b29b281f4b2c 100644 > > --- a/net/netfilter/nfnetlink.c > > +++ b/net/netfilter/nfnetlink.c > > @@ -427,6 +427,7 @@ static void nfnetlink_rcv_batch(struct sk_buff *skb, struct nlmsghdr *nlh, > > > > nfnl_unlock(subsys_id); > > > > + memset(&extack, 0, sizeof(extack)); > > if (nlh->nlmsg_flags & NLM_F_ACK) > > nfnl_err_add(&err_list, nlh, 0, &extack); > > > > -- > > 2.34.1 > >