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authorWillem de Bruijn <willemb@google.com>2020-07-01 16:00:06 -0400
committerDavid S. Miller <davem@davemloft.net>2020-07-01 17:38:30 -0700
commit0da7536fb47f51df89ccfcb1fa09f249d9accec5 (patch)
treec82adb4f2c69ea1284d6c450bbae33e833f1620f /net/ipv4/icmp.c
parente114e1e8ac9d31f25b9dd873bab5d80c1fc482ca (diff)
downloadlinux-0da7536fb47f51df89ccfcb1fa09f249d9accec5.tar.gz
ip: Fix SO_MARK in RST, ACK and ICMP packets
When no full socket is available, skbs are sent over a per-netns
control socket. Its sk_mark is temporarily adjusted to match that
of the real (request or timewait) socket or to reflect an incoming
skb, so that the outgoing skb inherits this in __ip_make_skb.

Introduction of the socket cookie mark field broke this. Now the
skb is set through the cookie and cork:

<caller>		# init sockc.mark from sk_mark or cmsg
ip_append_data
  ip_setup_cork		# convert sockc.mark to cork mark
ip_push_pending_frames
  ip_finish_skb
    __ip_make_skb	# set skb->mark to cork mark

But I missed these special control sockets. Update all callers of
__ip(6)_make_skb that were originally missed.

For IPv6, the same two icmp(v6) paths are affected. The third
case is not, as commit 92e55f412cff ("tcp: don't annotate
mark on control socket from tcp_v6_send_response()") replaced
the ctl_sk->sk_mark with passing the mark field directly as a
function argument. That commit predates the commit that
introduced the bug.

Fixes: c6af0c227a22 ("ip: support SO_MARK cmsg")
Signed-off-by: Willem de Bruijn <willemb@google.com>
Reported-by: Martin KaFai Lau <kafai@fb.com>
Reviewed-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/icmp.c')
-rw-r--r--net/ipv4/icmp.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/net/ipv4/icmp.c b/net/ipv4/icmp.c
index 956a806649f7..e30515f89802 100644
--- a/net/ipv4/icmp.c
+++ b/net/ipv4/icmp.c
@@ -427,7 +427,7 @@ static void icmp_reply(struct icmp_bxm *icmp_param, struct sk_buff *skb)
 
 	ipcm_init(&ipc);
 	inet->tos = ip_hdr(skb)->tos;
-	sk->sk_mark = mark;
+	ipc.sockc.mark = mark;
 	daddr = ipc.addr = ip_hdr(skb)->saddr;
 	saddr = fib_compute_spec_dst(skb);
 
@@ -710,10 +710,10 @@ void __icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info,
 	icmp_param.skb	  = skb_in;
 	icmp_param.offset = skb_network_offset(skb_in);
 	inet_sk(sk)->tos = tos;
-	sk->sk_mark = mark;
 	ipcm_init(&ipc);
 	ipc.addr = iph->saddr;
 	ipc.opt = &icmp_param.replyopts.opt;
+	ipc.sockc.mark = mark;
 
 	rt = icmp_route_lookup(net, &fl4, skb_in, iph, saddr, tos, mark,
 			       type, code, &icmp_param);