This is a note to let you know that I've just added the patch titled
ipv4: Fix potential uninit variable access bug in __ip_make_skb()
to the 6.3-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
ipv4-fix-potential-uninit-variable-access-bug-in-__i.patch
and it can be found in the queue-6.3 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 7b897edad796658c31c56c22d42c8788b7fefcc1
Author: Ziyang Xuan <william.xuanziyang@xxxxxxxxxx>
Date: Thu Apr 20 20:40:35 2023 +0800
ipv4: Fix potential uninit variable access bug in __ip_make_skb()
[ 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 <willemb@xxxxxxxxxx>
Signed-off-by: Ziyang Xuan <william.xuanziyang@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
index 4e4e308c3230a..89bd7872c6290 100644
--- a/net/ipv4/ip_output.c
+++ b/net/ipv4/ip_output.c
@@ -1570,9 +1570,19 @@ 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:
