From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 89313D512 for ; Mon, 15 May 2023 16:33:30 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id E013CC433EF; Mon, 15 May 2023 16:33:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1684168410; bh=mDgzfjAPKrsfbwPvzL4Z90EaGAz4BlY7kENVzOuNEYo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=10M5byIcAMW7hgI9klhfA53cR1HccnDVCUq2wXzcTztdmV/zzLzpkotzxKEyk61Qx N/CRJhOeqMr7AOiQuArRkpSWoRC+eZc7j8eapDOKfP2hgIqA3NdyE6Etj3tmfOvx9B 0LmPRFfvYwdvwIsyKVddGGw02xRXN6QpFK6xRk2s= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Willem de Bruijn , Ziyang Xuan , "David S. Miller" , Sasha Levin Subject: [PATCH 4.14 041/116] ipv4: Fix potential uninit variable access bug in __ip_make_skb() Date: Mon, 15 May 2023 18:25:38 +0200 Message-Id: <20230515161659.628375976@linuxfoundation.org> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20230515161658.228491273@linuxfoundation.org> References: <20230515161658.228491273@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Ziyang Xuan [ Upstream commit 99e5acae193e369b71217efe6f1dad42f3f18815 ] Like commit ea30388baebc ("ipv6: Fix an uninit variable access bug in __ip6_make_skb()"). icmphdr does not in skb linear region under the scenario of SOCK_RAW socket. Access icmp_hdr(skb)->type directly will trigger the uninit variable access bug. Use a local variable icmp_type to carry the correct value in different scenarios. Fixes: 96793b482540 ("[IPV4]: Add ICMPMsgStats MIB (RFC 4293)") Reviewed-by: Willem de Bruijn Signed-off-by: Ziyang Xuan Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- net/ipv4/ip_output.c | 16 +++++++++++++--- 1 file changed, 13 insertions(+), 3 deletions(-) diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c index aab18ab49e3b9..c5c9dc0f41cbc 100644 --- a/net/ipv4/ip_output.c +++ b/net/ipv4/ip_output.c @@ -1415,9 +1415,19 @@ struct sk_buff *__ip_make_skb(struct sock *sk, cork->dst = NULL; skb_dst_set(skb, &rt->dst); - if (iph->protocol == IPPROTO_ICMP) - icmp_out_count(net, ((struct icmphdr *) - skb_transport_header(skb))->type); + if (iph->protocol == IPPROTO_ICMP) { + u8 icmp_type; + + /* For such sockets, transhdrlen is zero when do ip_append_data(), + * so icmphdr does not in skb linear region and can not get icmp_type + * by icmp_hdr(skb)->type. + */ + if (sk->sk_type == SOCK_RAW && !inet_sk(sk)->hdrincl) + icmp_type = fl4->fl4_icmp_type; + else + icmp_type = icmp_hdr(skb)->type; + icmp_out_count(net, icmp_type); + } ip_cork_release(cork); out: -- 2.39.2