ipv6: sctp: clone options to avoid use after free (9470e24f) · Commits · 戴 / test

SCTP is lacking proper np->opt cloning at accept() time. TCP and DCCP use ipv6_dup_options() helper, do the same in SCTP. We might later factorize this code in a common helper to avoid future mistakes. Reported-by:

Dmitry Vyukov <dvyukov@google.com> Signed-off-by:

Eric Dumazet <edumazet@google.com> Acked-by:

Vlad Yasevich <vyasevich@gmail.com> Signed-off-by:

David S. Miller <davem@davemloft.net>

net/sctp/ipv6.c

+8 −0

Original line number	Diff line number	Diff line
		@@ -641,6 +641,7 @@ static struct sock sctp_v6_create_accept_sk(struct sock sk,
		struct sock *newsk;
		struct ipv6_pinfo newnp, np = inet6_sk(sk);
		struct sctp6_sock *newsctp6sk;
		struct ipv6_txoptions *opt;

		newsk = sk_alloc(sock_net(sk), PF_INET6, GFP_KERNEL, sk->sk_prot, 0);
		if (!newsk)
		@@ -660,6 +661,13 @@ static struct sock sctp_v6_create_accept_sk(struct sock sk,

		memcpy(newnp, np, sizeof(struct ipv6_pinfo));

		rcu_read_lock();
		opt = rcu_dereference(np->opt);
		if (opt)
		opt = ipv6_dup_options(newsk, opt);
		RCU_INIT_POINTER(newnp->opt, opt);
		rcu_read_unlock();

		/* Initialize sk's sport, dport, rcv_saddr and daddr for getsockname()
		* and getpeername().
		*/

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