From 264640fc2c5f4f913db5c73fa3eb1ead2c45e9d7 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Michal=20Kube=C4=8Dek?= Date: Tue, 24 Nov 2015 15:07:11 +0100 Subject: ipv6: distinguish frag queues by device for multicast and link-local packets If a fragmented multicast packet is received on an ethernet device which has an active macvlan on top of it, each fragment is duplicated and received both on the underlying device and the macvlan. If some fragments for macvlan are processed before the whole packet for the underlying device is reassembled, the "overlapping fragments" test in ip6_frag_queue() discards the whole fragment queue. To resolve this, add device ifindex to the search key and require it to match reassembling multicast packets and packets to link-local addresses. Note: similar patch has been already submitted by Yoshifuji Hideaki in http://patchwork.ozlabs.org/patch/220979/ but got lost and forgotten for some reason. Signed-off-by: Michal Kubecek Signed-off-by: David S. Miller --- include/net/ipv6.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/net/ipv6.h') diff --git a/include/net/ipv6.h b/include/net/ipv6.h index e1a10b0ac0b0..ea5a13ef85a6 100644 --- a/include/net/ipv6.h +++ b/include/net/ipv6.h @@ -490,6 +490,7 @@ struct ip6_create_arg { u32 user; const struct in6_addr *src; const struct in6_addr *dst; + int iif; u8 ecn; }; -- cgit v1.2.3 From 45f6fad84cc305103b28d73482b344d7f5b76f39 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Sun, 29 Nov 2015 19:37:57 -0800 Subject: ipv6: add complete rcu protection around np->opt This patch addresses multiple problems : UDP/RAW sendmsg() need to get a stable struct ipv6_txoptions while socket is not locked : Other threads can change np->opt concurrently. Dmitry posted a syzkaller (http://github.com/google/syzkaller) program desmonstrating use-after-free. Starting with TCP/DCCP lockless listeners, tcp_v6_syn_recv_sock() and dccp_v6_request_recv_sock() also need to use RCU protection to dereference np->opt once (before calling ipv6_dup_options()) This patch adds full RCU protection to np->opt Reported-by: Dmitry Vyukov Signed-off-by: Eric Dumazet Acked-by: Hannes Frederic Sowa Signed-off-by: David S. Miller --- include/net/ipv6.h | 21 ++++++++++++++++++++- 1 file changed, 20 insertions(+), 1 deletion(-) (limited to 'include/net/ipv6.h') diff --git a/include/net/ipv6.h b/include/net/ipv6.h index ea5a13ef85a6..9a5c9f013784 100644 --- a/include/net/ipv6.h +++ b/include/net/ipv6.h @@ -205,6 +205,7 @@ extern rwlock_t ip6_ra_lock; */ struct ipv6_txoptions { + atomic_t refcnt; /* Length of this structure */ int tot_len; @@ -217,7 +218,7 @@ struct ipv6_txoptions { struct ipv6_opt_hdr *dst0opt; struct ipv6_rt_hdr *srcrt; /* Routing Header */ struct ipv6_opt_hdr *dst1opt; - + struct rcu_head rcu; /* Option buffer, as read by IPV6_PKTOPTIONS, starts here. */ }; @@ -252,6 +253,24 @@ struct ipv6_fl_socklist { struct rcu_head rcu; }; +static inline struct ipv6_txoptions *txopt_get(const struct ipv6_pinfo *np) +{ + struct ipv6_txoptions *opt; + + rcu_read_lock(); + opt = rcu_dereference(np->opt); + if (opt && !atomic_inc_not_zero(&opt->refcnt)) + opt = NULL; + rcu_read_unlock(); + return opt; +} + +static inline void txopt_put(struct ipv6_txoptions *opt) +{ + if (opt && atomic_dec_and_test(&opt->refcnt)) + kfree_rcu(opt, rcu); +} + struct ip6_flowlabel *fl6_sock_lookup(struct sock *sk, __be32 label); struct ipv6_txoptions *fl6_merge_options(struct ipv6_txoptions *opt_space, struct ip6_flowlabel *fl, -- cgit v1.2.3