CVE-2012-3552 (published 2012-10-03T11:02Z)

Race condition in the IP implementation in the Linux kernel before 3.0 might allow remote attackers to cause a denial of service (slab corruption and system crash) by sending packets to an application that sets socket options during the handling of network traffic.

Severity: HIGH
CVSS v2 base score: 7.1 (AV:N/AC:M/Au:N/C:N/I:N/A:C)
CVSS v3 base score: 5.9, MEDIUM (CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H)

Weakness information:
cwe_id: CWE-362
cwe_name: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
description: The product contains a code sequence that can run concurrently with other code, and the code sequence requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence that is operating concurrently.
extended_description: 
            This can have security implications when the expected synchronization is in security-critical code, such as recording whether a user is authenticated or modifying important state information that should not be influenced by an outsider.
            A race condition occurs within concurrent environments, and is effectively a property of a code sequence. Depending on the context, a code sequence may be in the form of a function call, a small number of instructions, a series of program invocations, etc.
            A race condition violates these properties, which are closely related:
               
                  Exclusivity - the code sequence is given exclusive access to the shared resource, i.e., no other code sequence can modify properties of the shared resource before the original sequence has completed execution.
                  Atomicity - the code sequence is behaviorally atomic, i.e., no other thread or process can concurrently execute the same sequence of instructions (or a subset) against the same resource.
               
            A race condition exists when an "interfering code sequence" can still access the shared resource, violating exclusivity. Programmers may assume that certain code sequences execute too quickly to be affected by an interfering code sequence; when they are not, this violates atomicity. For example, the single "x++" statement may appear atomic at the code layer, but it is actually non-atomic at the instruction layer, since it involves a read (the original value of x), followed by a computation (x+1), followed by a write (save the result to x).
            The interfering code sequence could be "trusted" or "untrusted." A trusted interfering code sequence occurs within the product; it cannot be modified by the attacker, and it can only be invoked indirectly. An untrusted interfering code sequence can be authored directly by the attacker, and typically it is external to the vulnerable product.
         
         

Fix information:
repo_url: https://github.com/torvalds/linux
commit_details: repo_url: https://github.com/torvalds/linux
author: Eric Dumazet
author_date: 2011-04-21 09:45:37+00:00
msg: inet: add RCU protection to inet->opt

We lack proper synchronization to manipulate inet->opt ip_options

Problem is ip_make_skb() calls ip_setup_cork() and
ip_setup_cork() possibly makes a copy of ipc->opt (struct ip_options),
without any protection against another thread manipulating inet->opt.

Another thread can change inet->opt pointer and free old one under us.

Use RCU to protect inet->opt (changed to inet->inet_opt).

Instead of handling atomic refcounts, just copy ip_options when
necessary, to avoid cache line dirtying.

We cant insert an rcu_head in struct ip_options since its included in
skb->cb[], so this patch is large because I had to introduce a new
ip_options_rcu structure.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
repository: repo_url: https://github.com/torvalds/linux
repo_name: torvalds/linux
description: Linux kernel source tree
repo_language: C
owner: torvalds
file_changes: filename: inet_sock.h
change_type: ModificationType.MODIFY
diff: @@ -57,7 +57,15 @@ struct ip_options {
 	unsigned char	__data[0];
 };
 
-#define optlength(opt) (sizeof(struct ip_options) + opt->optlen)
+struct ip_options_rcu {
+	struct rcu_head rcu;
+	struct ip_options opt;
+};
+
+struct ip_options_data {
+	struct ip_options_rcu	opt;
+	char			data[40];
+};
 
 struct inet_request_sock {
 	struct request_sock	req;
@@ -78,7 +86,7 @@ struct inet_request_sock {
 				acked	   : 1,
 				no_srccheck: 1;
 	kmemcheck_bitfield_end(flags);
-	struct ip_options	*opt;
+	struct ip_options_rcu	*opt;
 };
 
 static inline struct inet_request_sock *inet_rsk(const struct request_sock *sk)
@@ -140,7 +148,7 @@ struct inet_sock {
 	__be16			inet_sport;
 	__u16			inet_id;
 
-	struct ip_options	*opt;
+	struct ip_options_rcu __rcu	*inet_opt;
 	__u8			tos;
 	__u8			min_ttl;
 	__u8			mc_ttl;

programming_language: C
filename: ip.h
change_type: ModificationType.MODIFY
diff: @@ -52,7 +52,7 @@ static inline unsigned int ip_hdrlen(const struct sk_buff *skb)
 struct ipcm_cookie {
 	__be32			addr;
 	int			oif;
-	struct ip_options	*opt;
+	struct ip_options_rcu	*opt;
 	__u8			tx_flags;
 };
 
@@ -92,7 +92,7 @@ extern int		igmp_mc_proc_init(void);
 
 extern int		ip_build_and_send_pkt(struct sk_buff *skb, struct sock *sk,
 					      __be32 saddr, __be32 daddr,
-					      struct ip_options *opt);
+					      struct ip_options_rcu *opt);
 extern int		ip_rcv(struct sk_buff *skb, struct net_device *dev,
 			       struct packet_type *pt, struct net_device *orig_dev);
 extern int		ip_local_deliver(struct sk_buff *skb);
@@ -416,14 +416,15 @@ extern int ip_forward(struct sk_buff *skb);
  *	Functions provided by ip_options.c
  */
  
-extern void ip_options_build(struct sk_buff *skb, struct ip_options *opt, __be32 daddr, struct rtable *rt, int is_frag);
+extern void ip_options_build(struct sk_buff *skb, struct ip_options *opt,
+			     __be32 daddr, struct rtable *rt, int is_frag);
 extern int ip_options_echo(struct ip_options *dopt, struct sk_buff *skb);
 extern void ip_options_fragment(struct sk_buff *skb);
 extern int ip_options_compile(struct net *net,
 			      struct ip_options *opt, struct sk_buff *skb);
-extern int ip_options_get(struct net *net, struct ip_options **optp,
+extern int ip_options_get(struct net *net, struct ip_options_rcu **optp,
 			  unsigned char *data, int optlen);
-extern int ip_options_get_from_user(struct net *net, struct ip_options **optp,
+extern int ip_options_get_from_user(struct net *net, struct ip_options_rcu **optp,
 				    unsigned char __user *data, int optlen);
 extern void ip_options_undo(struct ip_options * opt);
 extern void ip_forward_options(struct sk_buff *skb);

programming_language: C
filename: ipv4.c
change_type: ModificationType.MODIFY
diff: @@ -48,6 +48,7 @@ int dccp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
 	struct flowi4 fl4;
 	struct rtable *rt;
 	int err;
+	struct ip_options_rcu *inet_opt;
 
 	dp->dccps_role = DCCP_ROLE_CLIENT;
 
@@ -58,10 +59,13 @@ int dccp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
 		return -EAFNOSUPPORT;
 
 	nexthop = daddr = usin->sin_addr.s_addr;
-	if (inet->opt != NULL && inet->opt->srr) {
+
+	inet_opt = rcu_dereference_protected(inet->inet_opt,
+					     sock_owned_by_user(sk));
+	if (inet_opt != NULL && inet_opt->opt.srr) {
 		if (daddr == 0)
 			return -EINVAL;
-		nexthop = inet->opt->faddr;
+		nexthop = inet_opt->opt.faddr;
 	}
 
 	orig_sport = inet->inet_sport;
@@ -78,7 +82,7 @@ int dccp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
 		return -ENETUNREACH;
 	}
 
-	if (inet->opt == NULL || !inet->opt->srr)
+	if (inet_opt == NULL || !inet_opt->opt.srr)
 		daddr = rt->rt_dst;
 
 	if (inet->inet_saddr == 0)
@@ -89,8 +93,8 @@ int dccp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
 	inet->inet_daddr = daddr;
 
 	inet_csk(sk)->icsk_ext_hdr_len = 0;
-	if (inet->opt != NULL)
-		inet_csk(sk)->icsk_ext_hdr_len = inet->opt->optlen;
+	if (inet_opt)
+		inet_csk(sk)->icsk_ext_hdr_len = inet_opt->opt.optlen;
 	/*
 	 * Socket identity is still unknown (sport may be zero).
 	 * However we set state to DCCP_REQUESTING and not releasing socket
@@ -405,7 +409,7 @@ struct sock *dccp_v4_request_recv_sock(struct sock *sk, struct sk_buff *skb,
 	newinet->inet_daddr	= ireq->rmt_addr;
 	newinet->inet_rcv_saddr = ireq->loc_addr;
 	newinet->inet_saddr	= ireq->loc_addr;
-	newinet->opt	   = ireq->opt;
+	newinet->inet_opt	= ireq->opt;
 	ireq->opt	   = NULL;
 	newinet->mc_index  = inet_iif(skb);
 	newinet->mc_ttl	   = ip_hdr(skb)->ttl;

programming_language: C
filename: ipv6.c
change_type: ModificationType.MODIFY
diff: @@ -573,7 +573,7 @@ static struct sock *dccp_v6_request_recv_sock(struct sock *sk,
 
 	   First: no IPv4 options.
 	 */
-	newinet->opt = NULL;
+	newinet->inet_opt = NULL;
 
 	/* Clone RX bits */
 	newnp->rxopt.all = np->rxopt.all;

programming_language: C
filename: af_inet.c
change_type: ModificationType.MODIFY
diff: @@ -153,7 +153,7 @@ void inet_sock_destruct(struct sock *sk)
 	WARN_ON(sk->sk_wmem_queued);
 	WARN_ON(sk->sk_forward_alloc);
 
-	kfree(inet->opt);
+	kfree(rcu_dereference_protected(inet->inet_opt, 1));
 	dst_release(rcu_dereference_check(sk->sk_dst_cache, 1));
 	sk_refcnt_debug_dec(sk);
 }
@@ -1106,9 +1106,12 @@ static int inet_sk_reselect_saddr(struct sock *sk)
 	struct flowi4 fl4;
 	struct rtable *rt;
 	__be32 new_saddr;
+	struct ip_options_rcu *inet_opt;
 
-	if (inet->opt && inet->opt->srr)
-		daddr = inet->opt->faddr;
+	inet_opt = rcu_dereference_protected(inet->inet_opt,
+					     sock_owned_by_user(sk));
+	if (inet_opt && inet_opt->opt.srr)
+		daddr = inet_opt->opt.faddr;
 
 	/* Query new route. */
 	rt = ip_route_connect(&fl4, daddr, 0, RT_CONN_FLAGS(sk),
@@ -1148,6 +1151,7 @@ int inet_sk_rebuild_header(struct sock *sk)
 	struct inet_sock *inet = inet_sk(sk);
 	struct rtable *rt = (struct rtable *)__sk_dst_check(sk, 0);
 	__be32 daddr;
+	struct ip_options_rcu *inet_opt;
 	int err;
 
 	/* Route is OK, nothing to do. */
@@ -1155,9 +1159,12 @@ int inet_sk_rebuild_header(struct sock *sk)
 		return 0;
 
 	/* Reroute. */
+	rcu_read_lock();
+	inet_opt = rcu_dereference(inet->inet_opt);
 	daddr = inet->inet_daddr;
-	if (inet->opt && inet->opt->srr)
-		daddr = inet->opt->faddr;
+	if (inet_opt && inet_opt->opt.srr)
+		daddr = inet_opt->opt.faddr;
+	rcu_read_unlock();
 	rt = ip_route_output_ports(sock_net(sk), sk, daddr, inet->inet_saddr,
 				   inet->inet_dport, inet->inet_sport,
 				   sk->sk_protocol, RT_CONN_FLAGS(sk),

programming_language: C
filename: cipso_ipv4.c
change_type: ModificationType.MODIFY
diff: @@ -1857,6 +1857,11 @@ static int cipso_v4_genopt(unsigned char *buf, u32 buf_len,
 	return CIPSO_V4_HDR_LEN + ret_val;
 }
 
+static void opt_kfree_rcu(struct rcu_head *head)
+{
+	kfree(container_of(head, struct ip_options_rcu, rcu));
+}
+
 /**
  * cipso_v4_sock_setattr - Add a CIPSO option to a socket
  * @sk: the socket
@@ -1879,7 +1884,7 @@ int cipso_v4_sock_setattr(struct sock *sk,
 	unsigned char *buf = NULL;
 	u32 buf_len;
 	u32 opt_len;
-	struct ip_options *opt = NULL;
+	struct ip_options_rcu *old, *opt = NULL;
 	struct inet_sock *sk_inet;
 	struct inet_connection_sock *sk_conn;
 
@@ -1915,22 +1920,25 @@ int cipso_v4_sock_setattr(struct sock *sk,
 		ret_val = -ENOMEM;
 		goto socket_setattr_failure;
 	}
-	memcpy(opt->__data, buf, buf_len);
-	opt->optlen = opt_len;
-	opt->cipso = sizeof(struct iphdr);
+	memcpy(opt->opt.__data, buf, buf_len);
+	opt->opt.optlen = opt_len;
+	opt->opt.cipso = sizeof(struct iphdr);
 	kfree(buf);
 	buf = NULL;
 
 	sk_inet = inet_sk(sk);
+
+	old = rcu_dereference_protected(sk_inet->inet_opt, sock_owned_by_user(sk));
 	if (sk_inet->is_icsk) {
 		sk_conn = inet_csk(sk);
-		if (sk_inet->opt)
-			sk_conn->icsk_ext_hdr_len -= sk_inet->opt->optlen;
-		sk_conn->icsk_ext_hdr_len += opt->optlen;
+		if (old)
+			sk_conn->icsk_ext_hdr_len -= old->opt.optlen;
+		sk_conn->icsk_ext_hdr_len += opt->opt.optlen;
 		sk_conn->icsk_sync_mss(sk, sk_conn->icsk_pmtu_cookie);
 	}
-	opt = xchg(&sk_inet->opt, opt);
-	kfree(opt);
+	rcu_assign_pointer(sk_inet->inet_opt, opt);
+	if (old)
+		call_rcu(&old->rcu, opt_kfree_rcu);
 
 	return 0;
 
@@ -1960,7 +1968,7 @@ int cipso_v4_req_setattr(struct request_sock *req,
 	unsigned char *buf = NULL;
 	u32 buf_len;
 	u32 opt_len;
-	struct ip_options *opt = NULL;
+	struct ip_options_rcu *opt = NULL;
 	struct inet_request_sock *req_inet;
 
 	/* We allocate the maximum CIPSO option size here so we are probably
@@ -1988,15 +1996,16 @@ int cipso_v4_req_setattr(struct request_sock *req,
 		ret_val = -ENOMEM;
 		goto req_setattr_failure;
 	}
-	memcpy(opt->__data, buf, buf_len);
-	opt->optlen = opt_len;
-	opt->cipso = sizeof(struct iphdr);
+	memcpy(opt->opt.__data, buf, buf_len);
+	opt->opt.optlen = opt_len;
+	opt->opt.cipso = sizeof(struct iphdr);
 	kfree(buf);
 	buf = NULL;
 
 	req_inet = inet_rsk(req);
 	opt = xchg(&req_inet->opt, opt);
-	kfree(opt);
+	if (opt)
+		call_rcu(&opt->rcu, opt_kfree_rcu);
 
 	return 0;
 
@@ -2016,34 +2025,34 @@ int cipso_v4_req_setattr(struct request_sock *req,
  * values on failure.
  *
  */
-static int cipso_v4_delopt(struct ip_options **opt_ptr)
+static int cipso_v4_delopt(struct ip_options_rcu **opt_ptr)
 {
 	int hdr_delta = 0;
-	struct ip_options *opt = *opt_ptr;
+	struct ip_options_rcu *opt = *opt_ptr;
 
-	if (opt->srr || opt->rr || opt->ts || opt->router_alert) {
+	if (opt->opt.srr || opt->opt.rr || opt->opt.ts || opt->opt.router_alert) {
 		u8 cipso_len;
 		u8 cipso_off;
 		unsigned char *cipso_ptr;
 		int iter;
 		int optlen_new;
 
-		cipso_off = opt->cipso - sizeof(struct iphdr);
-		cipso_ptr = &opt->__data[cipso_off];
+		cipso_off = opt->opt.cipso - sizeof(struct iphdr);
+		cipso_ptr = &opt->opt.__data[cipso_off];
 		cipso_len = cipso_ptr[1];
 
-		if (opt->srr > opt->cipso)
-			opt->srr -= cipso_len;
-		if (opt->rr > opt->cipso)
-			opt->rr -= cipso_len;
-		if (opt->ts > opt->cipso)
-			opt->ts -= cipso_len;
-		if (opt->router_alert > opt->cipso)
-			opt->router_alert -= cipso_len;
-		opt->cipso = 0;
+		if (opt->opt.srr > opt->opt.cipso)
+			opt->opt.srr -= cipso_len;
+		if (opt->opt.rr > opt->opt.cipso)
+			opt->opt.rr -= cipso_len;
+		if (opt->opt.ts > opt->opt.cipso)
+			opt->opt.ts -= cipso_len;
+		if (opt->opt.router_alert > opt->opt.cipso)
+			opt->opt.router_alert -= cipso_len;
+		opt->opt.cipso = 0;
 
 		memmove(cipso_ptr, cipso_ptr + cipso_len,
-			opt->optlen - cipso_off - cipso_len);
+			opt->opt.optlen - cipso_off - cipso_len);
 
 		/* determining the new total option length is tricky because of
 		 * the padding necessary, the only thing i can think to do at
@@ -2052,21 +2061,21 @@ static int cipso_v4_delopt(struct ip_options **opt_ptr)
 		 * from there we can determine the new total option length */
 		iter = 0;
 		optlen_new = 0;
-		while (iter < opt->optlen)
-			if (opt->__data[iter] != IPOPT_NOP) {
-				iter += opt->__data[iter + 1];
+		while (iter < opt->opt.optlen)
+			if (opt->opt.__data[iter] != IPOPT_NOP) {
+				iter += opt->opt.__data[iter + 1];
 				optlen_new = iter;
 			} else
 				iter++;
-		hdr_delta = opt->optlen;
-		opt->optlen = (optlen_new + 3) & ~3;
-		hdr_delta -= opt->optlen;
+		hdr_delta = opt->opt.optlen;
+		opt->opt.optlen = (optlen_new + 3) & ~3;
+		hdr_delta -= opt->opt.optlen;
 	} else {
 		/* only the cipso option was present on the socket so we can
 		 * remove the entire option struct */
 		*opt_ptr = NULL;
-		hdr_delta = opt->optlen;
-		kfree(opt);
+		hdr_delta = opt->opt.optlen;
+		call_rcu(&opt->rcu, opt_kfree_rcu);
 	}
 
 	return hdr_delta;
@@ -2083,15 +2092,15 @@ static int cipso_v4_delopt(struct ip_options **opt_ptr)
 void cipso_v4_sock_delattr(struct sock *sk)
 {
 	int hdr_delta;
-	struct ip_options *opt;
+	struct ip_options_rcu *opt;
 	struct inet_sock *sk_inet;
 
 	sk_inet = inet_sk(sk);
-	opt = sk_inet->opt;
-	if (opt == NULL || opt->cipso == 0)
+	opt = rcu_dereference_protected(sk_inet->inet_opt, 1);
+	if (opt == NULL || opt->opt.cipso == 0)
 		return;
 
-	hdr_delta = cipso_v4_delopt(&sk_inet->opt);
+	hdr_delta = cipso_v4_delopt(&sk_inet->inet_opt);
 	if (sk_inet->is_icsk && hdr_delta > 0) {
 		struct inet_connection_sock *sk_conn = inet_csk(sk);
 		sk_conn->icsk_ext_hdr_len -= hdr_delta;
@@ -2109,12 +2118,12 @@ void cipso_v4_sock_delattr(struct sock *sk)
  */
 void cipso_v4_req_delattr(struct request_sock *req)
 {
-	struct ip_options *opt;
+	struct ip_options_rcu *opt;
 	struct inet_request_sock *req_inet;
 
 	req_inet = inet_rsk(req);
 	opt = req_inet->opt;
-	if (opt == NULL || opt->cipso == 0)
+	if (opt == NULL || opt->opt.cipso == 0)
 		return;
 
 	cipso_v4_delopt(&req_inet->opt);
@@ -2184,14 +2193,18 @@ static int cipso_v4_getattr(const unsigned char *cipso,
  */
 int cipso_v4_sock_getattr(struct sock *sk, struct netlbl_lsm_secattr *secattr)
 {
-	struct ip_options *opt;
+	struct ip_options_rcu *opt;
+	int res = -ENOMSG;
 
-	opt = inet_sk(sk)->opt;
-	if (opt == NULL || opt->cipso == 0)
-		return -ENOMSG;
-
-	return cipso_v4_getattr(opt->__data + opt->cipso - sizeof(struct iphdr),
-				secattr);
+	rcu_read_lock();
+	opt = rcu_dereference(inet_sk(sk)->inet_opt);
+	if (opt && opt->opt.cipso)
+		res = cipso_v4_getattr(opt->opt.__data +
+						opt->opt.cipso -
+						sizeof(struct iphdr),
+				       secattr);
+	rcu_read_unlock();
+	return res;
 }
 
 /**

programming_language: C
filename: icmp.c
change_type: ModificationType.MODIFY
diff: @@ -108,8 +108,7 @@ struct icmp_bxm {
 		__be32	       times[3];
 	} data;
 	int head_len;
-	struct ip_options replyopts;
-	unsigned char  optbuf[40];
+	struct ip_options_data replyopts;
 };
 
 /* An array of errno for error messages from dest unreach. */
@@ -333,7 +332,7 @@ static void icmp_reply(struct icmp_bxm *icmp_param, struct sk_buff *skb)
 	struct inet_sock *inet;
 	__be32 daddr;
 
-	if (ip_options_echo(&icmp_param->replyopts, skb))
+	if (ip_options_echo(&icmp_param->replyopts.opt.opt, skb))
 		return;
 
 	sk = icmp_xmit_lock(net);
@@ -347,10 +346,10 @@ static void icmp_reply(struct icmp_bxm *icmp_param, struct sk_buff *skb)
 	daddr = ipc.addr = rt->rt_src;
 	ipc.opt = NULL;
 	ipc.tx_flags = 0;
-	if (icmp_param->replyopts.optlen) {
-		ipc.opt = &icmp_param->replyopts;
-		if (ipc.opt->srr)
-			daddr = icmp_param->replyopts.faddr;
+	if (icmp_param->replyopts.opt.opt.optlen) {
+		ipc.opt = &icmp_param->replyopts.opt;
+		if (ipc.opt->opt.srr)
+			daddr = icmp_param->replyopts.opt.opt.faddr;
 	}
 	{
 		struct flowi4 fl4 = {
@@ -379,8 +378,8 @@ static struct rtable *icmp_route_lookup(struct net *net, struct sk_buff *skb_in,
 					struct icmp_bxm *param)
 {
 	struct flowi4 fl4 = {
-		.daddr = (param->replyopts.srr ?
-			  param->replyopts.faddr : iph->saddr),
+		.daddr = (param->replyopts.opt.opt.srr ?
+			  param->replyopts.opt.opt.faddr : iph->saddr),
 		.saddr = saddr,
 		.flowi4_tos = RT_TOS(tos),
 		.flowi4_proto = IPPROTO_ICMP,
@@ -581,7 +580,7 @@ void icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info)
 					   IPTOS_PREC_INTERNETCONTROL) :
 					  iph->tos;
 
-	if (ip_options_echo(&icmp_param.replyopts, skb_in))
+	if (ip_options_echo(&icmp_param.replyopts.opt.opt, skb_in))
 		goto out_unlock;
 
 
@@ -597,7 +596,7 @@ void icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info)
 	icmp_param.offset = skb_network_offset(skb_in);
 	inet_sk(sk)->tos = tos;
 	ipc.addr = iph->saddr;
-	ipc.opt = &icmp_param.replyopts;
+	ipc.opt = &icmp_param.replyopts.opt;
 	ipc.tx_flags = 0;
 
 	rt = icmp_route_lookup(net, skb_in, iph, saddr, tos,
@@ -613,7 +612,7 @@ void icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info)
 	room = dst_mtu(&rt->dst);
 	if (room > 576)
 		room = 576;
-	room -= sizeof(struct iphdr) + icmp_param.replyopts.optlen;
+	room -= sizeof(struct iphdr) + icmp_param.replyopts.opt.opt.optlen;
 	room -= sizeof(struct icmphdr);
 
 	icmp_param.data_len = skb_in->len - icmp_param.offset;

programming_language: C
filename: inet_connection_sock.c
change_type: ModificationType.MODIFY
diff: @@ -354,20 +354,20 @@ struct dst_entry *inet_csk_route_req(struct sock *sk,
 {
 	struct rtable *rt;
 	const struct inet_request_sock *ireq = inet_rsk(req);
-	struct ip_options *opt = inet_rsk(req)->opt;
+	struct ip_options_rcu *opt = inet_rsk(req)->opt;
 	struct net *net = sock_net(sk);
 	struct flowi4 fl4;
 
 	flowi4_init_output(&fl4, sk->sk_bound_dev_if, sk->sk_mark,
 			   RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE,
 			   sk->sk_protocol, inet_sk_flowi_flags(sk),
-			   (opt && opt->srr) ? opt->faddr : ireq->rmt_addr,
+			   (opt && opt->opt.srr) ? opt->opt.faddr : ireq->rmt_addr,
 			   ireq->loc_addr, ireq->rmt_port, inet_sk(sk)->inet_sport);
 	security_req_classify_flow(req, flowi4_to_flowi(&fl4));
 	rt = ip_route_output_flow(net, &fl4, sk);
 	if (IS_ERR(rt))
 		goto no_route;
-	if (opt && opt->is_strictroute && rt->rt_dst != rt->rt_gateway)
+	if (opt && opt->opt.is_strictroute && rt->rt_dst != rt->rt_gateway)
 		goto route_err;
 	return &rt->dst;
 

programming_language: C
filename: ip_options.c
change_type: ModificationType.MODIFY
diff: @@ -36,7 +36,7 @@
  * saddr is address of outgoing interface.
  */
 
-void ip_options_build(struct sk_buff * skb, struct ip_options * opt,
+void ip_options_build(struct sk_buff *skb, struct ip_options *opt,
 			    __be32 daddr, struct rtable *rt, int is_frag)
 {
 	unsigned char *iph = skb_network_header(skb);
@@ -83,9 +83,9 @@ void ip_options_build(struct sk_buff * skb, struct ip_options * opt,
  * NOTE: dopt cannot point to skb.
  */
 
-int ip_options_echo(struct ip_options * dopt, struct sk_buff * skb)
+int ip_options_echo(struct ip_options *dopt, struct sk_buff *skb)
 {
-	struct ip_options *sopt;
+	const struct ip_options *sopt;
 	unsigned char *sptr, *dptr;
 	int soffset, doffset;
 	int	optlen;
@@ -95,10 +95,8 @@ int ip_options_echo(struct ip_options * dopt, struct sk_buff * skb)
 
 	sopt = &(IPCB(skb)->opt);
 
-	if (sopt->optlen == 0) {
-		dopt->optlen = 0;
+	if (sopt->optlen == 0)
 		return 0;
-	}
 
 	sptr = skb_network_header(skb);
 	dptr = dopt->__data;
@@ -157,7 +155,7 @@ int ip_options_echo(struct ip_options * dopt, struct sk_buff * skb)
 		dopt->optlen += optlen;
 	}
 	if (sopt->srr) {
-		unsigned char * start = sptr+sopt->srr;
+		unsigned char *start = sptr+sopt->srr;
 		__be32 faddr;
 
 		optlen  = start[1];
@@ -499,19 +497,19 @@ void ip_options_undo(struct ip_options * opt)
 	}
 }
 
-static struct ip_options *ip_options_get_alloc(const int optlen)
+static struct ip_options_rcu *ip_options_get_alloc(const int optlen)
 {
-	return kzalloc(sizeof(struct ip_options) + ((optlen + 3) & ~3),
+	return kzalloc(sizeof(struct ip_options_rcu) + ((optlen + 3) & ~3),
 		       GFP_KERNEL);
 }
 
-static int ip_options_get_finish(struct net *net, struct ip_options **optp,
-				 struct ip_options *opt, int optlen)
+static int ip_options_get_finish(struct net *net, struct ip_options_rcu **optp,
+				 struct ip_options_rcu *opt, int optlen)
 {
 	while (optlen & 3)
-		opt->__data[optlen++] = IPOPT_END;
-	opt->optlen = optlen;
-	if (optlen && ip_options_compile(net, opt, NULL)) {
+		opt->opt.__data[optlen++] = IPOPT_END;
+	opt->opt.optlen = optlen;
+	if (optlen && ip_options_compile(net, &opt->opt, NULL)) {
 		kfree(opt);
 		return -EINVAL;
 	}
@@ -520,29 +518,29 @@ static int ip_options_get_finish(struct net *net, struct ip_options **optp,
 	return 0;
 }
 
-int ip_options_get_from_user(struct net *net, struct ip_options **optp,
+int ip_options_get_from_user(struct net *net, struct ip_options_rcu **optp,
 			     unsigned char __user *data, int optlen)
 {
-	struct ip_options *opt = ip_options_get_alloc(optlen);
+	struct ip_options_rcu *opt = ip_options_get_alloc(optlen);
 
 	if (!opt)
 		return -ENOMEM;
-	if (optlen && copy_from_user(opt->__data, data, optlen)) {
+	if (optlen && copy_from_user(opt->opt.__data, data, optlen)) {
 		kfree(opt);
 		return -EFAULT;
 	}
 	return ip_options_get_finish(net, optp, opt, optlen);
 }
 
-int ip_options_get(struct net *net, struct ip_options **optp,
+int ip_options_get(struct net *net, struct ip_options_rcu **optp,
 		   unsigned char *data, int optlen)
 {
-	struct ip_options *opt = ip_options_get_alloc(optlen);
+	struct ip_options_rcu *opt = ip_options_get_alloc(optlen);
 
 	if (!opt)
 		return -ENOMEM;
 	if (optlen)
-		memcpy(opt->__data, data, optlen);
+		memcpy(opt->opt.__data, data, optlen);
 	return ip_options_get_finish(net, optp, opt, optlen);
 }
 

programming_language: C
filename: ip_output.c
change_type: ModificationType.MODIFY
diff: @@ -140,14 +140,14 @@ static inline int ip_select_ttl(struct inet_sock *inet, struct dst_entry *dst)
  *
  */
 int ip_build_and_send_pkt(struct sk_buff *skb, struct sock *sk,
-			  __be32 saddr, __be32 daddr, struct ip_options *opt)
+			  __be32 saddr, __be32 daddr, struct ip_options_rcu *opt)
 {
 	struct inet_sock *inet = inet_sk(sk);
 	struct rtable *rt = skb_rtable(skb);
 	struct iphdr *iph;
 
 	/* Build the IP header. */
-	skb_push(skb, sizeof(struct iphdr) + (opt ? opt->optlen : 0));
+	skb_push(skb, sizeof(struct iphdr) + (opt ? opt->opt.optlen : 0));
 	skb_reset_network_header(skb);
 	iph = ip_hdr(skb);
 	iph->version  = 4;
@@ -163,9 +163,9 @@ int ip_build_and_send_pkt(struct sk_buff *skb, struct sock *sk,
 	iph->protocol = sk->sk_protocol;
 	ip_select_ident(iph, &rt->dst, sk);
 
-	if (opt && opt->optlen) {
-		iph->ihl += opt->optlen>>2;
-		ip_options_build(skb, opt, daddr, rt, 0);
+	if (opt && opt->opt.optlen) {
+		iph->ihl += opt->opt.optlen>>2;
+		ip_options_build(skb, &opt->opt, daddr, rt, 0);
 	}
 
 	skb->priority = sk->sk_priority;
@@ -316,7 +316,7 @@ int ip_queue_xmit(struct sk_buff *skb)
 {
 	struct sock *sk = skb->sk;
 	struct inet_sock *inet = inet_sk(sk);
-	struct ip_options *opt = inet->opt;
+	struct ip_options_rcu *inet_opt;
 	struct rtable *rt;
 	struct iphdr *iph;
 	int res;
@@ -325,6 +325,7 @@ int ip_queue_xmit(struct sk_buff *skb)
 	 * f.e. by something like SCTP.
 	 */
 	rcu_read_lock();
+	inet_opt = rcu_dereference(inet->inet_opt);
 	rt = skb_rtable(skb);
 	if (rt != NULL)
 		goto packet_routed;
@@ -336,8 +337,8 @@ int ip_queue_xmit(struct sk_buff *skb)
 
 		/* Use correct destination address if we have options. */
 		daddr = inet->inet_daddr;
-		if(opt && opt->srr)
-			daddr = opt->faddr;
+		if (inet_opt && inet_opt->opt.srr)
+			daddr = inet_opt->opt.faddr;
 
 		/* If this fails, retransmit mechanism of transport layer will
 		 * keep trying until route appears or the connection times
@@ -357,11 +358,11 @@ int ip_queue_xmit(struct sk_buff *skb)
 	skb_dst_set_noref(skb, &rt->dst);
 
 packet_routed:
-	if (opt && opt->is_strictroute && rt->rt_dst != rt->rt_gateway)
+	if (inet_opt && inet_opt->opt.is_strictroute && rt->rt_dst != rt->rt_gateway)
 		goto no_route;
 
 	/* OK, we know where to send it, allocate and build IP header. */
-	skb_push(skb, sizeof(struct iphdr) + (opt ? opt->optlen : 0));
+	skb_push(skb, sizeof(struct iphdr) + (inet_opt ? inet_opt->opt.optlen : 0));
 	skb_reset_network_header(skb);
 	iph = ip_hdr(skb);
 	*((__be16 *)iph) = htons((4 << 12) | (5 << 8) | (inet->tos & 0xff));
@@ -375,9 +376,9 @@ int ip_queue_xmit(struct sk_buff *skb)
 	iph->daddr    = rt->rt_dst;
 	/* Transport layer set skb->h.foo itself. */
 
-	if (opt && opt->optlen) {
-		iph->ihl += opt->optlen >> 2;
-		ip_options_build(skb, opt, inet->inet_daddr, rt, 0);
+	if (inet_opt && inet_opt->opt.optlen) {
+		iph->ihl += inet_opt->opt.optlen >> 2;
+		ip_options_build(skb, &inet_opt->opt, inet->inet_daddr, rt, 0);
 	}
 
 	ip_select_ident_more(iph, &rt->dst, sk,
@@ -1033,7 +1034,7 @@ static int ip_setup_cork(struct sock *sk, struct inet_cork *cork,
 			 struct ipcm_cookie *ipc, struct rtable **rtp)
 {
 	struct inet_sock *inet = inet_sk(sk);
-	struct ip_options *opt;
+	struct ip_options_rcu *opt;
 	struct rtable *rt;
 
 	/*
@@ -1047,7 +1048,7 @@ static int ip_setup_cork(struct sock *sk, struct inet_cork *cork,
 			if (unlikely(cork->opt == NULL))
 				return -ENOBUFS;
 		}
-		memcpy(cork->opt, opt, sizeof(struct ip_options) + opt->optlen);
+		memcpy(cork->opt, &opt->opt, sizeof(struct ip_options) + opt->opt.optlen);
 		cork->flags |= IPCORK_OPT;
 		cork->addr = ipc->addr;
 	}
@@ -1451,26 +1452,23 @@ void ip_send_reply(struct sock *sk, struct sk_buff *skb, struct ip_reply_arg *ar
 		   unsigned int len)
 {
 	struct inet_sock *inet = inet_sk(sk);
-	struct {
-		struct ip_options	opt;
-		char			data[40];
-	} replyopts;
+	struct ip_options_data replyopts;
 	struct ipcm_cookie ipc;
 	__be32 daddr;
 	struct rtable *rt = skb_rtable(skb);
 
-	if (ip_options_echo(&replyopts.opt, skb))
+	if (ip_options_echo(&replyopts.opt.opt, skb))
 		return;
 
 	daddr = ipc.addr = rt->rt_src;
 	ipc.opt = NULL;
 	ipc.tx_flags = 0;
 
-	if (replyopts.opt.optlen) {
+	if (replyopts.opt.opt.optlen) {
 		ipc.opt = &replyopts.opt;
 
-		if (ipc.opt->srr)
-			daddr = replyopts.opt.faddr;
+		if (replyopts.opt.opt.srr)
+			daddr = replyopts.opt.opt.faddr;
 	}
 
 	{

programming_language: C
filename: ip_sockglue.c
change_type: ModificationType.MODIFY
diff: @@ -451,6 +451,11 @@ int ip_recv_error(struct sock *sk, struct msghdr *msg, int len)
 }
 
 
+static void opt_kfree_rcu(struct rcu_head *head)
+{
+	kfree(container_of(head, struct ip_options_rcu, rcu));
+}
+
 /*
  *	Socket option code for IP. This is the end of the line after any
  *	TCP,UDP etc options on an IP socket.
@@ -497,13 +502,16 @@ static int do_ip_setsockopt(struct sock *sk, int level,
 	switch (optname) {
 	case IP_OPTIONS:
 	{
-		struct ip_options *opt = NULL;
+		struct ip_options_rcu *old, *opt = NULL;
+
 		if (optlen > 40)
 			goto e_inval;
 		err = ip_options_get_from_user(sock_net(sk), &opt,
 					       optval, optlen);
 		if (err)
 			break;
+		old = rcu_dereference_protected(inet->inet_opt,
+						sock_owned_by_user(sk));
 		if (inet->is_icsk) {
 			struct inet_connection_sock *icsk = inet_csk(sk);
 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
@@ -512,17 +520,18 @@ static int do_ip_setsockopt(struct sock *sk, int level,
 			       (TCPF_LISTEN | TCPF_CLOSE)) &&
 			     inet->inet_daddr != LOOPBACK4_IPV6)) {
 #endif
-				if (inet->opt)
-					icsk->icsk_ext_hdr_len -= inet->opt->optlen;
+				if (old)
+					icsk->icsk_ext_hdr_len -= old->opt.optlen;
 				if (opt)
-					icsk->icsk_ext_hdr_len += opt->optlen;
+					icsk->icsk_ext_hdr_len += opt->opt.optlen;
 				icsk->icsk_sync_mss(sk, icsk->icsk_pmtu_cookie);
 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
 			}
 #endif
 		}
-		opt = xchg(&inet->opt, opt);
-		kfree(opt);
+		rcu_assign_pointer(inet->inet_opt, opt);
+		if (old)
+			call_rcu(&old->rcu, opt_kfree_rcu);
 		break;
 	}
 	case IP_PKTINFO:
@@ -1081,12 +1090,16 @@ static int do_ip_getsockopt(struct sock *sk, int level, int optname,
 	case IP_OPTIONS:
 	{
 		unsigned char optbuf[sizeof(struct ip_options)+40];
-		struct ip_options * opt = (struct ip_options *)optbuf;
+		struct ip_options *opt = (struct ip_options *)optbuf;
+		struct ip_options_rcu *inet_opt;
+
+		inet_opt = rcu_dereference_protected(inet->inet_opt,
+						     sock_owned_by_user(sk));
 		opt->optlen = 0;
-		if (inet->opt)
-			memcpy(optbuf, inet->opt,
-			       sizeof(struct ip_options)+
-			       inet->opt->optlen);
+		if (inet_opt)
+			memcpy(optbuf, &inet_opt->opt,
+			       sizeof(struct ip_options) +
+			       inet_opt->opt.optlen);
 		release_sock(sk);
 
 		if (opt->optlen == 0)

programming_language: C
filename: raw.c
change_type: ModificationType.MODIFY
diff: @@ -460,6 +460,7 @@ static int raw_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
 	__be32 saddr;
 	u8  tos;
 	int err;
+	struct ip_options_data opt_copy;
 
 	err = -EMSGSIZE;
 	if (len > 0xFFFF)
@@ -520,8 +521,18 @@ static int raw_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
 	saddr = ipc.addr;
 	ipc.addr = daddr;
 
-	if (!ipc.opt)
-		ipc.opt = inet->opt;
+	if (!ipc.opt) {
+		struct ip_options_rcu *inet_opt;
+
+		rcu_read_lock();
+		inet_opt = rcu_dereference(inet->inet_opt);
+		if (inet_opt) {
+			memcpy(&opt_copy, inet_opt,
+			       sizeof(*inet_opt) + inet_opt->opt.optlen);
+			ipc.opt = &opt_copy.opt;
+		}
+		rcu_read_unlock();
+	}
 
 	if (ipc.opt) {
 		err = -EINVAL;
@@ -530,10 +541,10 @@ static int raw_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
 		 */
 		if (inet->hdrincl)
 			goto done;
-		if (ipc.opt->srr) {
+		if (ipc.opt->opt.srr) {
 			if (!daddr)
 				goto done;
-			daddr = ipc.opt->faddr;
+			daddr = ipc.opt->opt.faddr;
 		}
 	}
 	tos = RT_CONN_FLAGS(sk);

programming_language: C
filename: syncookies.c
change_type: ModificationType.MODIFY
diff: @@ -321,10 +321,10 @@ struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb,
 	 * the ACK carries the same options again (see RFC1122 4.2.3.8)
 	 */
 	if (opt && opt->optlen) {
-		int opt_size = sizeof(struct ip_options) + opt->optlen;
+		int opt_size = sizeof(struct ip_options_rcu) + opt->optlen;
 
 		ireq->opt = kmalloc(opt_size, GFP_ATOMIC);
-		if (ireq->opt != NULL && ip_options_echo(ireq->opt, skb)) {
+		if (ireq->opt != NULL && ip_options_echo(&ireq->opt->opt, skb)) {
 			kfree(ireq->opt);
 			ireq->opt = NULL;
 		}

programming_language: C
filename: tcp_ipv4.c
change_type: ModificationType.MODIFY
diff: @@ -154,6 +154,7 @@ int tcp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
 	struct flowi4 fl4;
 	struct rtable *rt;
 	int err;
+	struct ip_options_rcu *inet_opt;
 
 	if (addr_len < sizeof(struct sockaddr_in))
 		return -EINVAL;
@@ -162,10 +163,12 @@ int tcp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
 		return -EAFNOSUPPORT;
 
 	nexthop = daddr = usin->sin_addr.s_addr;
-	if (inet->opt && inet->opt->srr) {
+	inet_opt = rcu_dereference_protected(inet->inet_opt,
+					     sock_owned_by_user(sk));
+	if (inet_opt && inet_opt->opt.srr) {
 		if (!daddr)
 			return -EINVAL;
-		nexthop = inet->opt->faddr;
+		nexthop = inet_opt->opt.faddr;
 	}
 
 	orig_sport = inet->inet_sport;
@@ -186,7 +189,7 @@ int tcp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
 		return -ENETUNREACH;
 	}
 
-	if (!inet->opt || !inet->opt->srr)
+	if (!inet_opt || !inet_opt->opt.srr)
 		daddr = rt->rt_dst;
 
 	if (!inet->inet_saddr)
@@ -222,8 +225,8 @@ int tcp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
 	inet->inet_daddr = daddr;
 
 	inet_csk(sk)->icsk_ext_hdr_len = 0;
-	if (inet->opt)
-		inet_csk(sk)->icsk_ext_hdr_len = inet->opt->optlen;
+	if (inet_opt)
+		inet_csk(sk)->icsk_ext_hdr_len = inet_opt->opt.optlen;
 
 	tp->rx_opt.mss_clamp = TCP_MSS_DEFAULT;
 
@@ -820,17 +823,18 @@ static void syn_flood_warning(const struct sk_buff *skb)
 /*
  * Save and compile IPv4 options into the request_sock if needed.
  */
-static struct ip_options *tcp_v4_save_options(struct sock *sk,
-					      struct sk_buff *skb)
+static struct ip_options_rcu *tcp_v4_save_options(struct sock *sk,
+						  struct sk_buff *skb)
 {
-	struct ip_options *opt = &(IPCB(skb)->opt);
-	struct ip_options *dopt = NULL;
+	const struct ip_options *opt = &(IPCB(skb)->opt);
+	struct ip_options_rcu *dopt = NULL;
 
 	if (opt && opt->optlen) {
-		int opt_size = optlength(opt);
+		int opt_size = sizeof(*dopt) + opt->optlen;
+
 		dopt = kmalloc(opt_size, GFP_ATOMIC);
 		if (dopt) {
-			if (ip_options_echo(dopt, skb)) {
+			if (ip_options_echo(&dopt->opt, skb)) {
 				kfree(dopt);
 				dopt = NULL;
 			}
@@ -1411,6 +1415,7 @@ struct sock *tcp_v4_syn_recv_sock(struct sock *sk, struct sk_buff *skb,
 #ifdef CONFIG_TCP_MD5SIG
 	struct tcp_md5sig_key *key;
 #endif
+	struct ip_options_rcu *inet_opt;
 
 	if (sk_acceptq_is_full(sk))
 		goto exit_overflow;
@@ -1431,13 +1436,14 @@ struct sock *tcp_v4_syn_recv_sock(struct sock *sk, struct sk_buff *skb,
 	newinet->inet_daddr   = ireq->rmt_addr;
 	newinet->inet_rcv_saddr = ireq->loc_addr;
 	newinet->inet_saddr	      = ireq->loc_addr;
-	newinet->opt	      = ireq->opt;
+	inet_opt	      = ireq->opt;
+	rcu_assign_pointer(newinet->inet_opt, inet_opt);
 	ireq->opt	      = NULL;
 	newinet->mc_index     = inet_iif(skb);
 	newinet->mc_ttl	      = ip_hdr(skb)->ttl;
 	inet_csk(newsk)->icsk_ext_hdr_len = 0;
-	if (newinet->opt)
-		inet_csk(newsk)->icsk_ext_hdr_len = newinet->opt->optlen;
+	if (inet_opt)
+		inet_csk(newsk)->icsk_ext_hdr_len = inet_opt->opt.optlen;
 	newinet->inet_id = newtp->write_seq ^ jiffies;
 
 	tcp_mtup_init(newsk);

programming_language: C
filename: udp.c
change_type: ModificationType.MODIFY
diff: @@ -804,6 +804,7 @@ int udp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
 	int corkreq = up->corkflag || msg->msg_flags&MSG_MORE;
 	int (*getfrag)(void *, char *, int, int, int, struct sk_buff *);
 	struct sk_buff *skb;
+	struct ip_options_data opt_copy;
 
 	if (len > 0xFFFF)
 		return -EMSGSIZE;
@@ -877,22 +878,32 @@ int udp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
 			free = 1;
 		connected = 0;
 	}
-	if (!ipc.opt)
-		ipc.opt = inet->opt;
+	if (!ipc.opt) {
+		struct ip_options_rcu *inet_opt;
+
+		rcu_read_lock();
+		inet_opt = rcu_dereference(inet->inet_opt);
+		if (inet_opt) {
+			memcpy(&opt_copy, inet_opt,
+			       sizeof(*inet_opt) + inet_opt->opt.optlen);
+			ipc.opt = &opt_copy.opt;
+		}
+		rcu_read_unlock();
+	}
 
 	saddr = ipc.addr;
 	ipc.addr = faddr = daddr;
 
-	if (ipc.opt && ipc.opt->srr) {
+	if (ipc.opt && ipc.opt->opt.srr) {
 		if (!daddr)
 			return -EINVAL;
-		faddr = ipc.opt->faddr;
+		faddr = ipc.opt->opt.faddr;
 		connected = 0;
 	}
 	tos = RT_TOS(inet->tos);
 	if (sock_flag(sk, SOCK_LOCALROUTE) ||
 	    (msg->msg_flags & MSG_DONTROUTE) ||
-	    (ipc.opt && ipc.opt->is_strictroute)) {
+	    (ipc.opt && ipc.opt->opt.is_strictroute)) {
 		tos |= RTO_ONLINK;
 		connected = 0;
 	}

programming_language: C
filename: tcp_ipv6.c
change_type: ModificationType.MODIFY
diff: @@ -1469,7 +1469,7 @@ static struct sock * tcp_v6_syn_recv_sock(struct sock *sk, struct sk_buff *skb,
 
 	   First: no IPv4 options.
 	 */
-	newinet->opt = NULL;
+	newinet->inet_opt = NULL;
 	newnp->ipv6_fl_list = NULL;
 
 	/* Clone RX bits */

programming_language: C
filename: l2tp_ip.c
change_type: ModificationType.MODIFY
diff: @@ -416,7 +416,6 @@ static int l2tp_ip_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *m
 	int rc;
 	struct l2tp_ip_sock *lsa = l2tp_ip_sk(sk);
 	struct inet_sock *inet = inet_sk(sk);
-	struct ip_options *opt = inet->opt;
 	struct rtable *rt = NULL;
 	int connected = 0;
 	__be32 daddr;
@@ -471,9 +470,14 @@ static int l2tp_ip_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *m
 		rt = (struct rtable *) __sk_dst_check(sk, 0);
 
 	if (rt == NULL) {
+		struct ip_options_rcu *inet_opt;
+
+		inet_opt = rcu_dereference_protected(inet->inet_opt,
+						     sock_owned_by_user(sk));
+
 		/* Use correct destination address if we have options. */
-		if (opt && opt->srr)
-			daddr = opt->faddr;
+		if (inet_opt && inet_opt->opt.srr)
+			daddr = inet_opt->opt.faddr;
 
 		/* If this fails, retransmit mechanism of transport layer will
 		 * keep trying until route appears or the connection times

programming_language: C