From 132a55f3c5c0b1a364d32f65595ad8838c30a60e Mon Sep 17 00:00:00 2001 From: Herbert Xu Date: Tue, 3 Oct 2006 14:34:00 -0700 Subject: [PATCH] [UDP6]: Fix flowi clobbering The udp6_sendmsg function uses a shared buffer to store the flow without taking any locks. This leads to races with SMP. This patch moves the flowi object onto the stack. Signed-off-by: Herbert Xu Acked-by: James Morris Signed-off-by: David S. Miller --- net/ipv6/udp.c | 62 +++++++++++++++++++++++++------------------------- 1 file changed, 31 insertions(+), 31 deletions(-) diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c index 9662561701d1..552ec0f449af 100644 --- a/net/ipv6/udp.c +++ b/net/ipv6/udp.c @@ -546,7 +546,7 @@ static int udpv6_sendmsg(struct kiocb *iocb, struct sock *sk, struct in6_addr *daddr, *final_p = NULL, final; struct ipv6_txoptions *opt = NULL; struct ip6_flowlabel *flowlabel = NULL; - struct flowi *fl = &inet->cork.fl; + struct flowi fl; struct dst_entry *dst; int addr_len = msg->msg_namelen; int ulen = len; @@ -626,19 +626,19 @@ static int udpv6_sendmsg(struct kiocb *iocb, struct sock *sk, } ulen += sizeof(struct udphdr); - memset(fl, 0, sizeof(*fl)); + memset(&fl, 0, sizeof(fl)); if (sin6) { if (sin6->sin6_port == 0) return -EINVAL; - fl->fl_ip_dport = sin6->sin6_port; + fl.fl_ip_dport = sin6->sin6_port; daddr = &sin6->sin6_addr; if (np->sndflow) { - fl->fl6_flowlabel = sin6->sin6_flowinfo&IPV6_FLOWINFO_MASK; - if (fl->fl6_flowlabel&IPV6_FLOWLABEL_MASK) { - flowlabel = fl6_sock_lookup(sk, fl->fl6_flowlabel); + fl.fl6_flowlabel = sin6->sin6_flowinfo&IPV6_FLOWINFO_MASK; + if (fl.fl6_flowlabel&IPV6_FLOWLABEL_MASK) { + flowlabel = fl6_sock_lookup(sk, fl.fl6_flowlabel); if (flowlabel == NULL) return -EINVAL; daddr = &flowlabel->dst; @@ -656,32 +656,32 @@ static int udpv6_sendmsg(struct kiocb *iocb, struct sock *sk, if (addr_len >= sizeof(struct sockaddr_in6) && sin6->sin6_scope_id && ipv6_addr_type(daddr)&IPV6_ADDR_LINKLOCAL) - fl->oif = sin6->sin6_scope_id; + fl.oif = sin6->sin6_scope_id; } else { if (sk->sk_state != TCP_ESTABLISHED) return -EDESTADDRREQ; - fl->fl_ip_dport = inet->dport; + fl.fl_ip_dport = inet->dport; daddr = &np->daddr; - fl->fl6_flowlabel = np->flow_label; + fl.fl6_flowlabel = np->flow_label; connected = 1; } - if (!fl->oif) - fl->oif = sk->sk_bound_dev_if; + if (!fl.oif) + fl.oif = sk->sk_bound_dev_if; if (msg->msg_controllen) { opt = &opt_space; memset(opt, 0, sizeof(struct ipv6_txoptions)); opt->tot_len = sizeof(*opt); - err = datagram_send_ctl(msg, fl, opt, &hlimit, &tclass); + err = datagram_send_ctl(msg, &fl, opt, &hlimit, &tclass); if (err < 0) { fl6_sock_release(flowlabel); return err; } - if ((fl->fl6_flowlabel&IPV6_FLOWLABEL_MASK) && !flowlabel) { - flowlabel = fl6_sock_lookup(sk, fl->fl6_flowlabel); + if ((fl.fl6_flowlabel&IPV6_FLOWLABEL_MASK) && !flowlabel) { + flowlabel = fl6_sock_lookup(sk, fl.fl6_flowlabel); if (flowlabel == NULL) return -EINVAL; } @@ -695,39 +695,39 @@ static int udpv6_sendmsg(struct kiocb *iocb, struct sock *sk, opt = fl6_merge_options(&opt_space, flowlabel, opt); opt = ipv6_fixup_options(&opt_space, opt); - fl->proto = IPPROTO_UDP; - ipv6_addr_copy(&fl->fl6_dst, daddr); - if (ipv6_addr_any(&fl->fl6_src) && !ipv6_addr_any(&np->saddr)) - ipv6_addr_copy(&fl->fl6_src, &np->saddr); - fl->fl_ip_sport = inet->sport; + fl.proto = IPPROTO_UDP; + ipv6_addr_copy(&fl.fl6_dst, daddr); + if (ipv6_addr_any(&fl.fl6_src) && !ipv6_addr_any(&np->saddr)) + ipv6_addr_copy(&fl.fl6_src, &np->saddr); + fl.fl_ip_sport = inet->sport; /* merge ip6_build_xmit from ip6_output */ if (opt && opt->srcrt) { struct rt0_hdr *rt0 = (struct rt0_hdr *) opt->srcrt; - ipv6_addr_copy(&final, &fl->fl6_dst); - ipv6_addr_copy(&fl->fl6_dst, rt0->addr); + ipv6_addr_copy(&final, &fl.fl6_dst); + ipv6_addr_copy(&fl.fl6_dst, rt0->addr); final_p = &final; connected = 0; } - if (!fl->oif && ipv6_addr_is_multicast(&fl->fl6_dst)) { - fl->oif = np->mcast_oif; + if (!fl.oif && ipv6_addr_is_multicast(&fl.fl6_dst)) { + fl.oif = np->mcast_oif; connected = 0; } - security_sk_classify_flow(sk, fl); + security_sk_classify_flow(sk, &fl); - err = ip6_sk_dst_lookup(sk, &dst, fl); + err = ip6_sk_dst_lookup(sk, &dst, &fl); if (err) goto out; if (final_p) - ipv6_addr_copy(&fl->fl6_dst, final_p); + ipv6_addr_copy(&fl.fl6_dst, final_p); - if ((err = xfrm_lookup(&dst, fl, sk, 0)) < 0) + if ((err = xfrm_lookup(&dst, &fl, sk, 0)) < 0) goto out; if (hlimit < 0) { - if (ipv6_addr_is_multicast(&fl->fl6_dst)) + if (ipv6_addr_is_multicast(&fl.fl6_dst)) hlimit = np->mcast_hops; else hlimit = np->hop_limit; @@ -763,7 +763,7 @@ static int udpv6_sendmsg(struct kiocb *iocb, struct sock *sk, do_append_data: up->len += ulen; err = ip6_append_data(sk, ip_generic_getfrag, msg->msg_iov, ulen, - sizeof(struct udphdr), hlimit, tclass, opt, fl, + sizeof(struct udphdr), hlimit, tclass, opt, &fl, (struct rt6_info*)dst, corkreq ? msg->msg_flags|MSG_MORE : msg->msg_flags); if (err) @@ -774,10 +774,10 @@ static int udpv6_sendmsg(struct kiocb *iocb, struct sock *sk, if (dst) { if (connected) { ip6_dst_store(sk, dst, - ipv6_addr_equal(&fl->fl6_dst, &np->daddr) ? + ipv6_addr_equal(&fl.fl6_dst, &np->daddr) ? &np->daddr : NULL, #ifdef CONFIG_IPV6_SUBTREES - ipv6_addr_equal(&fl->fl6_src, &np->saddr) ? + ipv6_addr_equal(&fl.fl6_src, &np->saddr) ? &np->saddr : #endif NULL);