Commit 3257d8b1 authored Aug 10, 2015 by Eric Dumazet Committed by David S. Miller Aug 10, 2015

inet: fix possible request socket leak



In commit b357a364 ("inet: fix possible panic in
reqsk_queue_unlink()"), I missed fact that tcp_check_req()
can return the listener socket in one case, and that we must
release the request socket refcount or we leak it.

Tested:

 Following packetdrill test template shows the issue

0     socket(..., SOCK_STREAM, IPPROTO_TCP) = 3
+0    setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0
+0    bind(3, ..., ...) = 0
+0    listen(3, 1) = 0

+0    < S 0:0(0) win 2920 <mss 1460,sackOK,nop,nop>
+0    > S. 0:0(0) ack 1 <mss 1460,nop,nop,sackOK>
+.002 < . 1:1(0) ack 21 win 2920
+0    > R 21:21(0)

Fixes: b357a364 ("inet: fix possible panic in reqsk_queue_unlink()")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 2235f2ac

net/ipv4/tcp_ipv4.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -1348,7 +1348,7 @@ static struct sock tcp_v4_hnd_req(struct sock sk, struct sk_buff *skb)
		req = inet_csk_search_req(sk, th->source, iph->saddr, iph->daddr);
		if (req) {
		nsk = tcp_check_req(sk, skb, req, false);
		if (!nsk)
		if (!nsk \|\| nsk == sk)
		reqsk_put(req);
		return nsk;
		}

net/ipv6/tcp_ipv6.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -943,7 +943,7 @@ static struct sock tcp_v6_hnd_req(struct sock sk, struct sk_buff *skb)
		&ipv6_hdr(skb)->daddr, tcp_v6_iif(skb));
		if (req) {
		nsk = tcp_check_req(sk, skb, req, false);
		if (!nsk)
		if (!nsk \|\| nsk == sk)
		reqsk_put(req);
		return nsk;
		}

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