Commit 95fac540 authored by Jakub Kicinski's avatar Jakub Kicinski
Browse files

Merge branch 'raw-ping-fix-locking-in-proc-net-raw-icmp' 

Kuniyuki Iwashima says:

====================
raw/ping: Fix locking in /proc/net/{raw,icmp}.

The first patch fixes a NULL deref for /proc/net/raw and second one fixes
the same issue for ping sockets.

The first patch also converts hlist_nulls to hlist, but this is because
the current code uses sk_nulls_for_each() for lockless readers, instead
of sk_nulls_for_each_rcu() which adds memory barrier, but raw sockets
does not use the nulls marker nor SLAB_TYPESAFE_BY_RCU in the first place.

OTOH, the ping sockets already uses sk_nulls_for_each_rcu(), and such
conversion can be posted later for net-next.
====================

Link: https://lore.kernel.org/r/20230403194959.48928-1-kuniyu@amazon.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parents 218c5973 ab5fb73f

include/net/raw.h

+2 −2
Original line number Diff line number Diff line
@@ -37,7 +37,7 @@ int raw_rcv(struct sock *, struct sk_buff *); 
struct raw_hashinfo {

	spinlock_t lock;



	struct hlist_nulls_head ht[RAW_HTABLE_SIZE] ____cacheline_aligned;

	struct hlist_head ht[RAW_HTABLE_SIZE] ____cacheline_aligned;

};



static inline u32 raw_hashfunc(const struct net *net, u32 proto)
@@ -51,7 +51,7 @@ static inline void raw_hashinfo_init(struct raw_hashinfo *hashinfo) 


	spin_lock_init(&hashinfo->lock);

	for (i = 0; i < RAW_HTABLE_SIZE; i++)

		INIT_HLIST_NULLS_HEAD(&hashinfo->ht[i], i);

		INIT_HLIST_HEAD(&hashinfo->ht[i]);

}



#ifdef CONFIG_PROC_FS

net/ipv4/ping.c

+4 −4
Original line number Diff line number Diff line
@@ -1089,13 +1089,13 @@ static struct sock *ping_get_idx(struct seq_file *seq, loff_t pos) 
}



void *ping_seq_start(struct seq_file *seq, loff_t *pos, sa_family_t family)

	__acquires(RCU)

	__acquires(ping_table.lock)

{

	struct ping_iter_state *state = seq->private;

	state->bucket = 0;

	state->family = family;



	rcu_read_lock();

	spin_lock(&ping_table.lock);



	return *pos ? ping_get_idx(seq, *pos-1) : SEQ_START_TOKEN;

}
@@ -1121,9 +1121,9 @@ void *ping_seq_next(struct seq_file *seq, void *v, loff_t *pos) 
EXPORT_SYMBOL_GPL(ping_seq_next);



void ping_seq_stop(struct seq_file *seq, void *v)

	__releases(RCU)

	__releases(ping_table.lock)

{

	rcu_read_unlock();

	spin_unlock(&ping_table.lock);

}

EXPORT_SYMBOL_GPL(ping_seq_stop);

net/ipv4/raw.c

+19 −17
Original line number Diff line number Diff line
@@ -91,12 +91,12 @@ EXPORT_SYMBOL_GPL(raw_v4_hashinfo); 
int raw_hash_sk(struct sock *sk)

{

	struct raw_hashinfo *h = sk->sk_prot->h.raw_hash;

	struct hlist_nulls_head *hlist;

	struct hlist_head *hlist;



	hlist = &h->ht[raw_hashfunc(sock_net(sk), inet_sk(sk)->inet_num)];



	spin_lock(&h->lock);

	__sk_nulls_add_node_rcu(sk, hlist);

	sk_add_node_rcu(sk, hlist);

	sock_set_flag(sk, SOCK_RCU_FREE);

	spin_unlock(&h->lock);

	sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
@@ -110,7 +110,7 @@ void raw_unhash_sk(struct sock *sk) 
	struct raw_hashinfo *h = sk->sk_prot->h.raw_hash;



	spin_lock(&h->lock);

	if (__sk_nulls_del_node_init_rcu(sk))

	if (sk_del_node_init_rcu(sk))

		sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);

	spin_unlock(&h->lock);

}
@@ -163,16 +163,15 @@ static int icmp_filter(const struct sock *sk, const struct sk_buff *skb) 
static int raw_v4_input(struct net *net, struct sk_buff *skb,

			const struct iphdr *iph, int hash)

{

	struct hlist_nulls_head *hlist;

	struct hlist_nulls_node *hnode;

	int sdif = inet_sdif(skb);

	struct hlist_head *hlist;

	int dif = inet_iif(skb);

	int delivered = 0;

	struct sock *sk;



	hlist = &raw_v4_hashinfo.ht[hash];

	rcu_read_lock();

	sk_nulls_for_each(sk, hnode, hlist) {

	sk_for_each_rcu(sk, hlist) {

		if (!raw_v4_match(net, sk, iph->protocol,

				  iph->saddr, iph->daddr, dif, sdif))

			continue;
@@ -264,10 +263,9 @@ static void raw_err(struct sock *sk, struct sk_buff *skb, u32 info) 
void raw_icmp_error(struct sk_buff *skb, int protocol, u32 info)

{

	struct net *net = dev_net(skb->dev);

	struct hlist_nulls_head *hlist;

	struct hlist_nulls_node *hnode;

	int dif = skb->dev->ifindex;

	int sdif = inet_sdif(skb);

	struct hlist_head *hlist;

	const struct iphdr *iph;

	struct sock *sk;

	int hash;
@@ -276,7 +274,7 @@ void raw_icmp_error(struct sk_buff *skb, int protocol, u32 info) 
	hlist = &raw_v4_hashinfo.ht[hash];



	rcu_read_lock();

	sk_nulls_for_each(sk, hnode, hlist) {

	sk_for_each_rcu(sk, hlist) {

		iph = (const struct iphdr *)skb->data;

		if (!raw_v4_match(net, sk, iph->protocol,

				  iph->daddr, iph->saddr, dif, sdif))
@@ -950,14 +948,13 @@ static struct sock *raw_get_first(struct seq_file *seq, int bucket) 
{

	struct raw_hashinfo *h = pde_data(file_inode(seq->file));

	struct raw_iter_state *state = raw_seq_private(seq);

	struct hlist_nulls_head *hlist;

	struct hlist_nulls_node *hnode;

	struct hlist_head *hlist;

	struct sock *sk;



	for (state->bucket = bucket; state->bucket < RAW_HTABLE_SIZE;

			++state->bucket) {

		hlist = &h->ht[state->bucket];

		sk_nulls_for_each(sk, hnode, hlist) {

		sk_for_each(sk, hlist) {

			if (sock_net(sk) == seq_file_net(seq))

				return sk;

		}
@@ -970,7 +967,7 @@ static struct sock *raw_get_next(struct seq_file *seq, struct sock *sk) 
	struct raw_iter_state *state = raw_seq_private(seq);



	do {

		sk = sk_nulls_next(sk);

		sk = sk_next(sk);

	} while (sk && sock_net(sk) != seq_file_net(seq));



	if (!sk)
@@ -989,9 +986,12 @@ static struct sock *raw_get_idx(struct seq_file *seq, loff_t pos) 
}



void *raw_seq_start(struct seq_file *seq, loff_t *pos)

	__acquires(RCU)

	__acquires(&h->lock)

{

	rcu_read_lock();

	struct raw_hashinfo *h = pde_data(file_inode(seq->file));



	spin_lock(&h->lock);



	return *pos ? raw_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;

}

EXPORT_SYMBOL_GPL(raw_seq_start);
@@ -1010,9 +1010,11 @@ void *raw_seq_next(struct seq_file *seq, void *v, loff_t *pos) 
EXPORT_SYMBOL_GPL(raw_seq_next);



void raw_seq_stop(struct seq_file *seq, void *v)

	__releases(RCU)

	__releases(&h->lock)

{

	rcu_read_unlock();

	struct raw_hashinfo *h = pde_data(file_inode(seq->file));



	spin_unlock(&h->lock);

}

EXPORT_SYMBOL_GPL(raw_seq_stop);

net/ipv4/raw_diag.c

+4 −6
Original line number Diff line number Diff line
@@ -57,8 +57,7 @@ static bool raw_lookup(struct net *net, struct sock *sk, 
static struct sock *raw_sock_get(struct net *net, const struct inet_diag_req_v2 *r)

{

	struct raw_hashinfo *hashinfo = raw_get_hashinfo(r);

	struct hlist_nulls_head *hlist;

	struct hlist_nulls_node *hnode;

	struct hlist_head *hlist;

	struct sock *sk;

	int slot;
@@ -68,7 +67,7 @@ static struct sock *raw_sock_get(struct net *net, const struct inet_diag_req_v2 
	rcu_read_lock();

	for (slot = 0; slot < RAW_HTABLE_SIZE; slot++) {

		hlist = &hashinfo->ht[slot];

		sk_nulls_for_each(sk, hnode, hlist) {

		sk_for_each_rcu(sk, hlist) {

			if (raw_lookup(net, sk, r)) {

				/*

				 * Grab it and keep until we fill
@@ -142,9 +141,8 @@ static void raw_diag_dump(struct sk_buff *skb, struct netlink_callback *cb, 
	struct raw_hashinfo *hashinfo = raw_get_hashinfo(r);

	struct net *net = sock_net(skb->sk);

	struct inet_diag_dump_data *cb_data;

	struct hlist_nulls_head *hlist;

	struct hlist_nulls_node *hnode;

	int num, s_num, slot, s_slot;

	struct hlist_head *hlist;

	struct sock *sk = NULL;

	struct nlattr *bc;
@@ -161,7 +159,7 @@ static void raw_diag_dump(struct sk_buff *skb, struct netlink_callback *cb, 
		num = 0;



		hlist = &hashinfo->ht[slot];

		sk_nulls_for_each(sk, hnode, hlist) {

		sk_for_each_rcu(sk, hlist) {

			struct inet_sock *inet = inet_sk(sk);



			if (!net_eq(sock_net(sk), net))

net/ipv6/raw.c

+4 −6
Original line number Diff line number Diff line
@@ -141,10 +141,9 @@ EXPORT_SYMBOL(rawv6_mh_filter_unregister); 
static bool ipv6_raw_deliver(struct sk_buff *skb, int nexthdr)

{

	struct net *net = dev_net(skb->dev);

	struct hlist_nulls_head *hlist;

	struct hlist_nulls_node *hnode;

	const struct in6_addr *saddr;

	const struct in6_addr *daddr;

	struct hlist_head *hlist;

	struct sock *sk;

	bool delivered = false;

	__u8 hash;
@@ -155,7 +154,7 @@ static bool ipv6_raw_deliver(struct sk_buff *skb, int nexthdr) 
	hash = raw_hashfunc(net, nexthdr);

	hlist = &raw_v6_hashinfo.ht[hash];

	rcu_read_lock();

	sk_nulls_for_each(sk, hnode, hlist) {

	sk_for_each_rcu(sk, hlist) {

		int filtered;



		if (!raw_v6_match(net, sk, nexthdr, daddr, saddr,
@@ -333,15 +332,14 @@ void raw6_icmp_error(struct sk_buff *skb, int nexthdr, 
		u8 type, u8 code, int inner_offset, __be32 info)

{

	struct net *net = dev_net(skb->dev);

	struct hlist_nulls_head *hlist;

	struct hlist_nulls_node *hnode;

	struct hlist_head *hlist;

	struct sock *sk;

	int hash;



	hash = raw_hashfunc(net, nexthdr);

	hlist = &raw_v6_hashinfo.ht[hash];

	rcu_read_lock();

	sk_nulls_for_each(sk, hnode, hlist) {

	sk_for_each_rcu(sk, hlist) {

		/* Note: ipv6_hdr(skb) != skb->data */

		const struct ipv6hdr *ip6h = (const struct ipv6hdr *)skb->data;