| From | Kamal Mostafa <> | Subject | [PATCH 3.13.y-ckt 007/108] ipv6: sctp: clone options to avoid use after free | Date | Fri, 22 Jan 2016 15:28:20 -0800 |
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3.13.11-ckt33 -stable review patch. If anyone has any objections, please let me know.
---8<------------------------------------------------------------
From: Eric Dumazet <edumazet@google.com>
[ Upstream commit 9470e24f35ab81574da54e69df90c1eb4a96b43f ]
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> Signed-off-by: Kamal Mostafa <kamal@canonical.com> --- net/sctp/ipv6.c | 8 ++++++++ 1 file changed, 8 insertions(+)
diff --git a/net/sctp/ipv6.c b/net/sctp/ipv6.c index 7567e6f..526e88c 100644 --- a/net/sctp/ipv6.c +++ b/net/sctp/ipv6.c @@ -638,6 +638,7 @@ 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); if (!newsk) @@ -657,6 +658,13 @@ 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(). */ -- 1.9.1
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