Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Fix error output of boot instance creation failure

   Currently if a boot instance creation fails, instead of printing out
   the name of the instance that failed, it prints "(null)". That is
   because it prints "cur_str" that had already been processed by
   strsep(). Print the saved name instead.

   While at it, print the error code of the failure.

 - Fix use-after-free for same named historgrams

   Histograms can be named so that they can be used in multiple events.
   But if the named histogram has a variable attached, the second event
   that uses the named histogram which duplicates it and needs to free
   the original after duplication leaves the old variable in place and
   still visible. If another histogram uses than variable, it will use
   the stale one which will try to reference the freed duplicate
   histogram and crash the kernel.

   Free the duplicate variables along with the duplicated histogram
   data.

 - Check return value of kthread_run() in event self test

   The events self tests uses a kthread for testing but does not check
   if it succeeded in creating a kthread. If the kthread creation were
   to fail, the code will still try to call kthread_stop() on the error
   returned.

 - Fix race between reading trace_pipe and updating subbuffer size

   If a user is reading the trace_pipe file at the same time they update
   the ring buffer sub-buffer size, can cause the trace_pipe read to
   read stale data. Add trace_access_lock() around updating the ring
   buffer sub-buffer size.

 - Fix eventfs_inode on failure path in creation of the events directory

   In the creation of the "events" directory, if after allocating the
   eventfs_inode a failure is detected, it calls cleanup_ei() which
   calls free_ei(). The free_ei() will test if eventfs_inode being freed
   has no children. It is a bug if it does. But on the failure case of
   the creation of the "events" directory, the children lists have not
   yet been initialized and the free will trigger a warning because
   list_empty() on an uninitialized list returns false.

   Move the initialization into init_ei() where it makes more sense and
   makes sure that a created eventfs_inode has its lists initialized
   upon creation.

 - Check return value of kthread_run() in ftrace direct sample code

   The sample code that shows how to use the ftrace direct calls does
   not test the return of kthread_run() to see if it succeeds. Return a
   failure if the kthread_run() doesn't succeed.

 - Clear user events state on fork in case of alloc failure

   On fork, the child gets a pointer to the parent's user events state.
   It makes a copy of it then updates the child's pointer to it. But if
   the allocation fails, the duplication function leaves the child with
   a pointer to its parent's descriptor. When the child cleans up its
   data, it will free the parent's descriptor while the parent is still
   using it.

   In the duplication function, set the child's user_event_mm to NULL
   before testing if the allocation succeeded, and when it exits it will
   not free the parent's descriptor.

 - Fix retry exhaustion in simple ring buffer reader swap

   simple_ring_buffer_swap_reader_page() starts with retry set to 8 and
   post-decrements it only after a failed link replacement. On the final
   attempt, a successful replacement leaves retry at zero, while a
   failed replacement leaves it at -1.

   But the check for success expects the retry value to be non-zero and
   exits with an error on zero. This is the opposite result. Fix it.

 - Fail nicely when the remote swap_reader_page() returns an error

   Currently, if the swap_reader_page() of a remote buffer fails, it
   triggers a WARN_ON_ONCE() and continues normally. Instead, have it
   exit with an error and a pr_warn() print instead of a full WARNING.

* tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  ring-buffer: Stop remote reader update when page swap fails
  tracing: Fix retry exhaustion in simple ring buffer reader swap
  tracing/user_events: Clear copied tracing state before fork duplication
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify
  eventfs: Initialize ei->children and ei->list in init_ei()
  tracing: Fix use-after-free in trace_pipe read on sub-buffer order change
  tracing: Fix crash passing ERR_PTR to kthread_stop()
  tracing: Fix use-after-free with same-name named triggers
  tracing: Fix logged instance name on creation failure

1 files changed, 1171 insertions, 0 deletions

diff --git a/net/ipv4/ping.c b/net/ipv4/ping.c
new file mode 100644
index 000000000..d36f1e273
--- /dev/null
+++ b/net/ipv4/ping.c
@@ -0,0 +1,1171 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * INET		An implementation of the TCP/IP protocol suite for the LINUX
+ *		operating system.  INET is implemented using the  BSD Socket
+ *		interface as the means of communication with the user level.
+ *
+ *		"Ping" sockets
+ *
+ * Based on ipv4/udp.c code.
+ *
+ * Authors:	Vasiliy Kulikov / Openwall (for Linux 2.6),
+ *		Pavel Kankovsky (for Linux 2.4.32)
+ *
+ * Pavel gave all rights to bugs to Vasiliy,
+ * none of the bugs are Pavel's now.
+ */
+
+#include <linux/uaccess.h>
+#include <linux/types.h>
+#include <linux/fcntl.h>
+#include <linux/socket.h>
+#include <linux/sockios.h>
+#include <linux/in.h>
+#include <linux/errno.h>
+#include <linux/timer.h>
+#include <linux/mm.h>
+#include <linux/inet.h>
+#include <linux/netdevice.h>
+#include <net/snmp.h>
+#include <net/ip.h>
+#include <net/icmp.h>
+#include <net/protocol.h>
+#include <linux/skbuff.h>
+#include <linux/proc_fs.h>
+#include <linux/export.h>
+#include <linux/bpf-cgroup.h>
+#include <net/sock.h>
+#include <net/ping.h>
+#include <net/udp.h>
+#include <net/route.h>
+#include <net/inet_common.h>
+#include <net/checksum.h>
+
+#if IS_ENABLED(CONFIG_IPV6)
+#include <linux/in6.h>
+#include <linux/icmpv6.h>
+#include <net/addrconf.h>
+#include <net/ipv6.h>
+#include <net/transp_v6.h>
+#endif
+
+struct ping_table {
+	struct hlist_head	hash[PING_HTABLE_SIZE];
+	spinlock_t		lock;
+};
+
+static struct ping_table ping_table;
+struct pingv6_ops pingv6_ops;
+
+static inline u32 ping_hashfn(const struct net *net, u32 num, u32 mask)
+{
+	u32 res = (num + net_hash_mix(net)) & mask;
+
+	pr_debug("hash(%u) = %u\n", num, res);
+	return res;
+}
+
+static inline struct hlist_head *ping_hashslot(struct ping_table *table,
+					       struct net *net, unsigned int num)
+{
+	return &table->hash[ping_hashfn(net, num, PING_HTABLE_MASK)];
+}
+
+int ping_get_port(struct sock *sk, unsigned short ident)
+{
+	struct net *net = sock_net(sk);
+	struct inet_sock *isk, *isk2;
+	struct hlist_head *hlist;
+	struct sock *sk2 = NULL;
+
+	isk = inet_sk(sk);
+	spin_lock(&ping_table.lock);
+	if (ident == 0) {
+		u16 result = net->ipv4.ping_port_rover + 1;
+		u32 i;
+
+		for (i = 0; i < (1L << 16); i++, result++) {
+			if (!result)
+				continue; /* avoid zero */
+			hlist = ping_hashslot(&ping_table, net, result);
+			sk_for_each(sk2, hlist) {
+				if (!net_eq(sock_net(sk2), net))
+					continue;
+				isk2 = inet_sk(sk2);
+
+				if (isk2->inet_num == result)
+					goto next_port;
+			}
+
+			/* found */
+			net->ipv4.ping_port_rover = ident = result;
+			break;
+next_port:
+			;
+		}
+		if (i >= (1L << 16))
+			goto fail;
+	} else {
+		hlist = ping_hashslot(&ping_table, net, ident);
+		sk_for_each(sk2, hlist) {
+			if (!net_eq(sock_net(sk2), net))
+				continue;
+			isk2 = inet_sk(sk2);
+
+			/* BUG? Why is this reuse and not reuseaddr? ping.c
+			 * doesn't turn off SO_REUSEADDR, and it doesn't expect
+			 * that other ping processes can steal its packets.
+			 */
+			if ((isk2->inet_num == ident) &&
+			    (sk2 != sk) &&
+			    (!sk2->sk_reuse || !sk->sk_reuse))
+				goto fail;
+		}
+	}
+
+	pr_debug("found port/ident = %d\n", ident);
+	isk->inet_num = ident;
+	if (sk_unhashed(sk)) {
+		pr_debug("was not hashed\n");
+		sk_add_node_rcu(sk, hlist);
+		sock_set_flag(sk, SOCK_RCU_FREE);
+		sock_prot_inuse_add(net, sk->sk_prot, 1);
+	}
+	spin_unlock(&ping_table.lock);
+	return 0;
+
+fail:
+	spin_unlock(&ping_table.lock);
+	return -EADDRINUSE;
+}
+
+void ping_unhash(struct sock *sk)
+{
+	struct inet_sock *isk = inet_sk(sk);
+
+	pr_debug("ping_unhash(isk=%p,isk->num=%u)\n", isk, isk->inet_num);
+	spin_lock(&ping_table.lock);
+	if (sk_del_node_init_rcu(sk)) {
+		WRITE_ONCE(isk->inet_num, 0);
+		isk->inet_sport = 0;
+		sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
+	}
+	spin_unlock(&ping_table.lock);
+}
+
+/* Called under rcu_read_lock() */
+static struct sock *ping_lookup(struct net *net, struct sk_buff *skb, u16 ident)
+{
+	struct hlist_head *hslot = ping_hashslot(&ping_table, net, ident);
+	struct sock *sk = NULL;
+	struct inet_sock *isk;
+	int dif, sdif;
+
+	if (skb->protocol == htons(ETH_P_IP)) {
+		dif = inet_iif(skb);
+		sdif = inet_sdif(skb);
+		pr_debug("try to find: num = %d, daddr = %pI4, dif = %d\n",
+			 (int)ident, &ip_hdr(skb)->daddr, dif);
+#if IS_ENABLED(CONFIG_IPV6)
+	} else if (skb->protocol == htons(ETH_P_IPV6)) {
+		dif = inet6_iif(skb);
+		sdif = inet6_sdif(skb);
+		pr_debug("try to find: num = %d, daddr = %pI6c, dif = %d\n",
+			 (int)ident, &ipv6_hdr(skb)->daddr, dif);
+#endif
+	} else {
+		return NULL;
+	}
+
+	sk_for_each_rcu(sk, hslot) {
+		int bound_dev_if;
+
+		if (!net_eq(sock_net(sk), net))
+			continue;
+		isk = inet_sk(sk);
+
+		pr_debug("iterate\n");
+		if (READ_ONCE(isk->inet_num) != ident)
+			continue;
+
+		bound_dev_if = READ_ONCE(sk->sk_bound_dev_if);
+		if (skb->protocol == htons(ETH_P_IP) &&
+		    sk->sk_family == AF_INET) {
+			__be32 rcv_saddr = READ_ONCE(isk->inet_rcv_saddr);
+
+			pr_debug("found: %p: num=%d, daddr=%pI4, dif=%d\n", sk,
+				 ident, &rcv_saddr,
+				 bound_dev_if);
+
+			if (rcv_saddr && rcv_saddr != ip_hdr(skb)->daddr)
+				continue;
+#if IS_ENABLED(CONFIG_IPV6)
+		} else if (skb->protocol == htons(ETH_P_IPV6) &&
+			   sk->sk_family == AF_INET6) {
+
+			pr_debug("found: %p: num=%d, daddr=%pI6c, dif=%d\n", sk,
+				 ident,
+				 &sk->sk_v6_rcv_saddr,
+				 bound_dev_if);
+
+			if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr) &&
+			    !ipv6_addr_equal(&sk->sk_v6_rcv_saddr,
+					     &ipv6_hdr(skb)->daddr))
+				continue;
+#endif
+		} else {
+			continue;
+		}
+
+		if (bound_dev_if && bound_dev_if != dif &&
+		    bound_dev_if != sdif)
+			continue;
+
+		goto exit;
+	}
+
+	sk = NULL;
+exit:
+
+	return sk;
+}
+
+static void inet_get_ping_group_range_net(struct net *net, kgid_t *low,
+					  kgid_t *high)
+{
+	kgid_t *data = net->ipv4.ping_group_range.range;
+	unsigned int seq;
+
+	do {
+		seq = read_seqbegin(&net->ipv4.ping_group_range.lock);
+
+		*low = data[0];
+		*high = data[1];
+	} while (read_seqretry(&net->ipv4.ping_group_range.lock, seq));
+}
+
+
+int ping_init_sock(struct sock *sk)
+{
+	struct net *net = sock_net(sk);
+	kgid_t group = current_egid();
+	struct group_info *group_info;
+	int i;
+	kgid_t low, high;
+	int ret = 0;
+
+	if (sk->sk_family == AF_INET6)
+		sk->sk_ipv6only = 1;
+
+	inet_get_ping_group_range_net(net, &low, &high);
+	if (gid_lte(low, group) && gid_lte(group, high))
+		return 0;
+
+	group_info = get_current_groups();
+	for (i = 0; i < group_info->ngroups; i++) {
+		kgid_t gid = group_info->gid[i];
+
+		if (gid_lte(low, gid) && gid_lte(gid, high))
+			goto out_release_group;
+	}
+
+	ret = -EACCES;
+
+out_release_group:
+	put_group_info(group_info);
+	return ret;
+}
+
+void ping_close(struct sock *sk, long timeout)
+{
+	pr_debug("ping_close(sk=%p,sk->num=%u)\n",
+		 inet_sk(sk), inet_sk(sk)->inet_num);
+	pr_debug("isk->refcnt = %d\n", refcount_read(&sk->sk_refcnt));
+
+	sk_common_release(sk);
+}
+
+static int ping_pre_connect(struct sock *sk, struct sockaddr_unsized *uaddr,
+			    int addr_len)
+{
+	/* This check is replicated from __ip4_datagram_connect() and
+	 * intended to prevent BPF program called below from accessing bytes
+	 * that are out of the bound specified by user in addr_len.
+	 */
+	if (addr_len < sizeof(struct sockaddr_in))
+		return -EINVAL;
+
+	return BPF_CGROUP_RUN_PROG_INET4_CONNECT_LOCK(sk, uaddr, &addr_len);
+}
+
+/* Checks the bind address and possibly modifies sk->sk_bound_dev_if. */
+static int ping_check_bind_addr(struct sock *sk, struct inet_sock *isk,
+				struct sockaddr_unsized *uaddr, int addr_len)
+{
+	struct net *net = sock_net(sk);
+	if (sk->sk_family == AF_INET) {
+		struct sockaddr_in *addr = (struct sockaddr_in *) uaddr;
+		u32 tb_id = RT_TABLE_LOCAL;
+		int chk_addr_ret;
+
+		if (addr_len < sizeof(*addr))
+			return -EINVAL;
+
+		if (addr->sin_family != AF_INET &&
+		    !(addr->sin_family == AF_UNSPEC &&
+		      addr->sin_addr.s_addr == htonl(INADDR_ANY)))
+			return -EAFNOSUPPORT;
+
+		pr_debug("ping_check_bind_addr(sk=%p,addr=%pI4,port=%d)\n",
+			 sk, &addr->sin_addr.s_addr, ntohs(addr->sin_port));
+
+		if (addr->sin_addr.s_addr == htonl(INADDR_ANY))
+			return 0;
+
+		tb_id = l3mdev_fib_table_by_index(net, sk->sk_bound_dev_if) ? : tb_id;
+		chk_addr_ret = inet_addr_type_table(net, addr->sin_addr.s_addr, tb_id);
+
+		if (chk_addr_ret == RTN_MULTICAST ||
+		    chk_addr_ret == RTN_BROADCAST ||
+		    (chk_addr_ret != RTN_LOCAL &&
+		     !inet_can_nonlocal_bind(net, isk)))
+			return -EADDRNOTAVAIL;
+
+#if IS_ENABLED(CONFIG_IPV6)
+	} else if (sk->sk_family == AF_INET6) {
+		struct sockaddr_in6 *addr = (struct sockaddr_in6 *) uaddr;
+		int addr_type, scoped, has_addr;
+		struct net_device *dev = NULL;
+
+		if (addr_len < sizeof(*addr))
+			return -EINVAL;
+
+		if (addr->sin6_family != AF_INET6)
+			return -EAFNOSUPPORT;
+
+		pr_debug("ping_check_bind_addr(sk=%p,addr=%pI6c,port=%d)\n",
+			 sk, addr->sin6_addr.s6_addr, ntohs(addr->sin6_port));
+
+		addr_type = ipv6_addr_type(&addr->sin6_addr);
+		scoped = __ipv6_addr_needs_scope_id(addr_type);
+		if ((addr_type != IPV6_ADDR_ANY &&
+		     !(addr_type & IPV6_ADDR_UNICAST)) ||
+		    (scoped && !addr->sin6_scope_id))
+			return -EINVAL;
+
+		rcu_read_lock();
+		if (addr->sin6_scope_id) {
+			dev = dev_get_by_index_rcu(net, addr->sin6_scope_id);
+			if (!dev) {
+				rcu_read_unlock();
+				return -ENODEV;
+			}
+		}
+
+		if (!dev && sk->sk_bound_dev_if) {
+			dev = dev_get_by_index_rcu(net, sk->sk_bound_dev_if);
+			if (!dev) {
+				rcu_read_unlock();
+				return -ENODEV;
+			}
+		}
+		has_addr = pingv6_ops.ipv6_chk_addr(net, &addr->sin6_addr, dev,
+						    scoped);
+		rcu_read_unlock();
+
+		if (!(ipv6_can_nonlocal_bind(net, isk) || has_addr ||
+		      addr_type == IPV6_ADDR_ANY))
+			return -EADDRNOTAVAIL;
+
+		if (scoped)
+			sk->sk_bound_dev_if = addr->sin6_scope_id;
+#endif
+	} else {
+		return -EAFNOSUPPORT;
+	}
+	return 0;
+}
+
+static void ping_set_saddr(struct sock *sk, struct sockaddr_unsized *saddr)
+{
+	if (saddr->sa_family == AF_INET) {
+		struct inet_sock *isk = inet_sk(sk);
+		struct sockaddr_in *addr = (struct sockaddr_in *) saddr;
+
+		isk->inet_saddr = addr->sin_addr.s_addr;
+		WRITE_ONCE(isk->inet_rcv_saddr, addr->sin_addr.s_addr);
+#if IS_ENABLED(CONFIG_IPV6)
+	} else if (saddr->sa_family == AF_INET6) {
+		struct sockaddr_in6 *addr = (struct sockaddr_in6 *) saddr;
+		struct ipv6_pinfo *np = inet6_sk(sk);
+		sk->sk_v6_rcv_saddr = np->saddr = addr->sin6_addr;
+#endif
+	}
+}
+
+/*
+ * We need our own bind because there are no privileged id's == local ports.
+ * Moreover, we don't allow binding to multi- and broadcast addresses.
+ */
+
+int ping_bind(struct sock *sk, struct sockaddr_unsized *uaddr, int addr_len)
+{
+	struct inet_sock *isk = inet_sk(sk);
+	unsigned short snum;
+	int err;
+	int dif = sk->sk_bound_dev_if;
+
+	err = ping_check_bind_addr(sk, isk, uaddr, addr_len);
+	if (err)
+		return err;
+
+	lock_sock(sk);
+
+	err = -EINVAL;
+	if (isk->inet_num != 0)
+		goto out;
+
+	err = -EADDRINUSE;
+	snum = ntohs(((struct sockaddr_in *)uaddr)->sin_port);
+	if (ping_get_port(sk, snum) != 0) {
+		/* Restore possibly modified sk->sk_bound_dev_if by ping_check_bind_addr(). */
+		sk->sk_bound_dev_if = dif;
+		goto out;
+	}
+	ping_set_saddr(sk, uaddr);
+
+	pr_debug("after bind(): num = %hu, dif = %d\n",
+		 isk->inet_num,
+		 sk->sk_bound_dev_if);
+
+	err = 0;
+	if (sk->sk_family == AF_INET && isk->inet_rcv_saddr)
+		sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
+#if IS_ENABLED(CONFIG_IPV6)
+	if (sk->sk_family == AF_INET6 && !ipv6_addr_any(&sk->sk_v6_rcv_saddr))
+		sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
+#endif
+
+	if (snum)
+		sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
+	isk->inet_sport = htons(isk->inet_num);
+	isk->inet_daddr = 0;
+	isk->inet_dport = 0;
+
+#if IS_ENABLED(CONFIG_IPV6)
+	if (sk->sk_family == AF_INET6)
+		memset(&sk->sk_v6_daddr, 0, sizeof(sk->sk_v6_daddr));
+#endif
+
+	sk_dst_reset(sk);
+out:
+	release_sock(sk);
+	pr_debug("ping_v4_bind -> %d\n", err);
+	return err;
+}
+
+/*
+ * Is this a supported type of ICMP message?
+ */
+
+static inline int ping_supported(int family, int type, int code)
+{
+	return (family == AF_INET && type == ICMP_ECHO && code == 0) ||
+	       (family == AF_INET && type == ICMP_EXT_ECHO && code == 0) ||
+	       (family == AF_INET6 && type == ICMPV6_ECHO_REQUEST && code == 0) ||
+	       (family == AF_INET6 && type == ICMPV6_EXT_ECHO_REQUEST && code == 0);
+}
+
+/*
+ * This routine is called by the ICMP module when it gets some
+ * sort of error condition.
+ */
+
+void ping_err(struct sk_buff *skb, int offset, u32 info)
+{
+	int family;
+	struct icmphdr *icmph;
+	struct inet_sock *inet_sock;
+	int type;
+	int code;
+	struct net *net = dev_net(skb->dev);
+	struct sock *sk;
+	int harderr;
+	int err;
+
+	if (skb->protocol == htons(ETH_P_IP)) {
+		family = AF_INET;
+		type = icmp_hdr(skb)->type;
+		code = icmp_hdr(skb)->code;
+		icmph = (struct icmphdr *)(skb->data + offset);
+	} else if (skb->protocol == htons(ETH_P_IPV6)) {
+		family = AF_INET6;
+		type = icmp6_hdr(skb)->icmp6_type;
+		code = icmp6_hdr(skb)->icmp6_code;
+		icmph = (struct icmphdr *) (skb->data + offset);
+	} else {
+		BUG();
+	}
+
+	/* We assume the packet has already been checked by icmp_unreach */
+
+	if (!ping_supported(family, icmph->type, icmph->code))
+		return;
+
+	pr_debug("ping_err(proto=0x%x,type=%d,code=%d,id=%04x,seq=%04x)\n",
+		 skb->protocol, type, code, ntohs(icmph->un.echo.id),
+		 ntohs(icmph->un.echo.sequence));
+
+	sk = ping_lookup(net, skb, ntohs(icmph->un.echo.id));
+	if (!sk) {
+		pr_debug("no socket, dropping\n");
+		return;	/* No socket for error */
+	}
+	pr_debug("err on socket %p\n", sk);
+
+	err = 0;
+	harderr = 0;
+	inet_sock = inet_sk(sk);
+
+	if (skb->protocol == htons(ETH_P_IP)) {
+		switch (type) {
+		default:
+		case ICMP_TIME_EXCEEDED:
+			err = EHOSTUNREACH;
+			break;
+		case ICMP_SOURCE_QUENCH:
+			/* This is not a real error but ping wants to see it.
+			 * Report it with some fake errno.
+			 */
+			err = EREMOTEIO;
+			break;
+		case ICMP_PARAMETERPROB:
+			err = EPROTO;
+			harderr = 1;
+			break;
+		case ICMP_DEST_UNREACH:
+			if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */
+				ipv4_sk_update_pmtu(skb, sk, info);
+				if (READ_ONCE(inet_sock->pmtudisc) != IP_PMTUDISC_DONT) {
+					err = EMSGSIZE;
+					harderr = 1;
+					break;
+				}
+				goto out;
+			}
+			err = EHOSTUNREACH;
+			if (code <= NR_ICMP_UNREACH) {
+				harderr = icmp_err_convert[code].fatal;
+				err = icmp_err_convert[code].errno;
+			}
+			break;
+		case ICMP_REDIRECT:
+			/* See ICMP_SOURCE_QUENCH */
+			ipv4_sk_redirect(skb, sk);
+			err = EREMOTEIO;
+			break;
+		}
+#if IS_ENABLED(CONFIG_IPV6)
+	} else if (skb->protocol == htons(ETH_P_IPV6)) {
+		harderr = pingv6_ops.icmpv6_err_convert(type, code, &err);
+#endif
+	}
+
+	/*
+	 *      RFC1122: OK.  Passes ICMP errors back to application, as per
+	 *	4.1.3.3.
+	 */
+	if ((family == AF_INET && !inet_test_bit(RECVERR, sk)) ||
+	    (family == AF_INET6 && !inet6_test_bit(RECVERR6, sk))) {
+		if (!harderr || sk->sk_state != TCP_ESTABLISHED)
+			goto out;
+	} else {
+		if (family == AF_INET) {
+			ip_icmp_error(sk, skb, err, 0 /* no remote port */,
+				      info, (u8 *)icmph);
+#if IS_ENABLED(CONFIG_IPV6)
+		} else if (family == AF_INET6) {
+			pingv6_ops.ipv6_icmp_error(sk, skb, err, 0,
+						   info, (u8 *)icmph);
+#endif
+		}
+	}
+	sk->sk_err = err;
+	sk_error_report(sk);
+out:
+	return;
+}
+
+/*
+ *	Copy and checksum an ICMP Echo packet from user space into a buffer
+ *	starting from the payload.
+ */
+
+int ping_getfrag(void *from, char *to,
+		 int offset, int fraglen, int odd, struct sk_buff *skb)
+{
+	struct pingfakehdr *pfh = from;
+
+	if (!csum_and_copy_from_iter_full(to, fraglen, &pfh->wcheck,
+					  &pfh->msg->msg_iter))
+		return -EFAULT;
+
+#if IS_ENABLED(CONFIG_IPV6)
+	/* For IPv6, checksum each skb as we go along, as expected by
+	 * icmpv6_push_pending_frames. For IPv4, accumulate the checksum in
+	 * wcheck, it will be finalized in ping_v4_push_pending_frames.
+	 */
+	if (pfh->family == AF_INET6) {
+		skb->csum = csum_block_add(skb->csum, pfh->wcheck, odd);
+		skb->ip_summed = CHECKSUM_NONE;
+		pfh->wcheck = 0;
+	}
+#endif
+
+	return 0;
+}
+
+static int ping_v4_push_pending_frames(struct sock *sk, struct pingfakehdr *pfh,
+				       struct flowi4 *fl4)
+{
+	struct sk_buff *skb = skb_peek(&sk->sk_write_queue);
+
+	if (!skb)
+		return 0;
+	pfh->wcheck = csum_partial((char *)&pfh->icmph,
+		sizeof(struct icmphdr), pfh->wcheck);
+	pfh->icmph.checksum = csum_fold(pfh->wcheck);
+	memcpy(icmp_hdr(skb), &pfh->icmph, sizeof(struct icmphdr));
+	skb->ip_summed = CHECKSUM_NONE;
+	return ip_push_pending_frames(sk, fl4);
+}
+
+int ping_common_sendmsg(int family, struct msghdr *msg, size_t len,
+			void *user_icmph, size_t icmph_len)
+{
+	u8 type, code;
+
+	if (len > 0xFFFF)
+		return -EMSGSIZE;
+
+	/* Must have at least a full ICMP header. */
+	if (len < icmph_len)
+		return -EINVAL;
+
+	/*
+	 *	Check the flags.
+	 */
+
+	/* Mirror BSD error message compatibility */
+	if (msg->msg_flags & MSG_OOB)
+		return -EOPNOTSUPP;
+
+	/*
+	 *	Fetch the ICMP header provided by the userland.
+	 *	iovec is modified! The ICMP header is consumed.
+	 */
+	if (memcpy_from_msg(user_icmph, msg, icmph_len))
+		return -EFAULT;
+
+	if (family == AF_INET) {
+		type = ((struct icmphdr *) user_icmph)->type;
+		code = ((struct icmphdr *) user_icmph)->code;
+#if IS_ENABLED(CONFIG_IPV6)
+	} else if (family == AF_INET6) {
+		type = ((struct icmp6hdr *) user_icmph)->icmp6_type;
+		code = ((struct icmp6hdr *) user_icmph)->icmp6_code;
+#endif
+	} else {
+		BUG();
+	}
+
+	if (!ping_supported(family, type, code))
+		return -EINVAL;
+
+	return 0;
+}
+
+static int ping_v4_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
+{
+	DEFINE_RAW_FLEX(struct ip_options_rcu, opt_copy, opt.__data,
+			IP_OPTIONS_DATA_FIXED_SIZE);
+	struct net *net = sock_net(sk);
+	struct flowi4 fl4;
+	struct inet_sock *inet = inet_sk(sk);
+	struct ipcm_cookie ipc;
+	struct icmphdr user_icmph;
+	struct pingfakehdr pfh;
+	struct rtable *rt = NULL;
+	int free = 0;
+	__be32 saddr, daddr, faddr;
+	u8 scope;
+	int err;
+
+	pr_debug("ping_v4_sendmsg(sk=%p,sk->num=%u)\n", inet, inet->inet_num);
+
+	err = ping_common_sendmsg(AF_INET, msg, len, &user_icmph,
+				  sizeof(user_icmph));
+	if (err)
+		return err;
+
+	/*
+	 *	Get and verify the address.
+	 */
+
+	if (msg->msg_name) {
+		DECLARE_SOCKADDR(struct sockaddr_in *, usin, msg->msg_name);
+		if (msg->msg_namelen < sizeof(*usin))
+			return -EINVAL;
+		if (usin->sin_family != AF_INET)
+			return -EAFNOSUPPORT;
+		daddr = usin->sin_addr.s_addr;
+		/* no remote port */
+	} else {
+		if (sk->sk_state != TCP_ESTABLISHED)
+			return -EDESTADDRREQ;
+		daddr = inet->inet_daddr;
+		/* no remote port */
+	}
+
+	ipcm_init_sk(&ipc, inet);
+
+	if (msg->msg_controllen) {
+		err = ip_cmsg_send(sk, msg, &ipc, false);
+		if (unlikely(err)) {
+			kfree(ipc.opt);
+			return err;
+		}
+		if (ipc.opt)
+			free = 1;
+	}
+	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;
+		}
+		rcu_read_unlock();
+	}
+
+	saddr = ipc.addr;
+	ipc.addr = faddr = daddr;
+
+	if (ipc.opt && ipc.opt->opt.srr) {
+		if (!daddr) {
+			err = -EINVAL;
+			goto out_free;
+		}
+		faddr = ipc.opt->opt.faddr;
+	}
+	scope = ip_sendmsg_scope(inet, &ipc, msg);
+
+	if (ipv4_is_multicast(daddr)) {
+		if (!ipc.oif || netif_index_is_l3_master(sock_net(sk), ipc.oif))
+			ipc.oif = READ_ONCE(inet->mc_index);
+		if (!saddr)
+			saddr = READ_ONCE(inet->mc_addr);
+	} else if (!ipc.oif)
+		ipc.oif = READ_ONCE(inet->uc_index);
+
+	flowi4_init_output(&fl4, ipc.oif, ipc.sockc.mark,
+			   ipc.tos & INET_DSCP_MASK, scope,
+			   sk->sk_protocol, inet_sk_flowi_flags(sk), faddr,
+			   saddr, 0, 0, sk_uid(sk));
+
+	fl4.fl4_icmp_type = user_icmph.type;
+	fl4.fl4_icmp_code = user_icmph.code;
+
+	security_sk_classify_flow(sk, flowi4_to_flowi_common(&fl4));
+	rt = ip_route_output_flow(net, &fl4, sk);
+	if (IS_ERR(rt)) {
+		err = PTR_ERR(rt);
+		rt = NULL;
+		if (err == -ENETUNREACH)
+			IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES);
+		goto out;
+	}
+
+	err = -EACCES;
+	if ((rt->rt_flags & RTCF_BROADCAST) &&
+	    !sock_flag(sk, SOCK_BROADCAST))
+		goto out;
+
+	if (msg->msg_flags & MSG_CONFIRM)
+		goto do_confirm;
+back_from_confirm:
+
+	if (!ipc.addr)
+		ipc.addr = fl4.daddr;
+
+	lock_sock(sk);
+
+	pfh.icmph.type = user_icmph.type; /* already checked */
+	pfh.icmph.code = user_icmph.code; /* ditto */
+	pfh.icmph.checksum = 0;
+	pfh.icmph.un.echo.id = inet->inet_sport;
+	pfh.icmph.un.echo.sequence = user_icmph.un.echo.sequence;
+	pfh.msg = msg;
+	pfh.wcheck = 0;
+	pfh.family = AF_INET;
+
+	err = ip_append_data(sk, &fl4, ping_getfrag, &pfh, len,
+			     sizeof(struct icmphdr), &ipc, &rt,
+			     msg->msg_flags);
+	if (err)
+		ip_flush_pending_frames(sk);
+	else
+		err = ping_v4_push_pending_frames(sk, &pfh, &fl4);
+	release_sock(sk);
+
+out:
+	ip_rt_put(rt);
+out_free:
+	if (free)
+		kfree(ipc.opt);
+	if (!err)
+		return len;
+	return err;
+
+do_confirm:
+	if (msg->msg_flags & MSG_PROBE)
+		dst_confirm_neigh(&rt->dst, &fl4.daddr);
+	if (!(msg->msg_flags & MSG_PROBE) || len)
+		goto back_from_confirm;
+	err = 0;
+	goto out;
+}
+
+int ping_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int flags)
+{
+	struct inet_sock *isk = inet_sk(sk);
+	int family = sk->sk_family;
+	struct sk_buff *skb;
+	int copied, err;
+
+	pr_debug("ping_recvmsg(sk=%p,sk->num=%u)\n", isk,
+		 READ_ONCE(isk->inet_num));
+
+	err = -EOPNOTSUPP;
+	if (flags & MSG_OOB)
+		goto out;
+
+	if (flags & MSG_ERRQUEUE)
+		return inet_recv_error(sk, msg, len);
+
+	skb = skb_recv_datagram(sk, flags, &err);
+	if (!skb)
+		goto out;
+
+	copied = skb->len;
+	if (copied > len) {
+		msg->msg_flags |= MSG_TRUNC;
+		copied = len;
+	}
+
+	/* Don't bother checking the checksum */
+	err = skb_copy_datagram_msg(skb, 0, msg, copied);
+	if (err)
+		goto done;
+
+	sock_recv_timestamp(msg, sk, skb);
+
+	/* Copy the address and add cmsg data. */
+	if (family == AF_INET) {
+		DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name);
+
+		if (sin) {
+			sin->sin_family = AF_INET;
+			sin->sin_port = 0 /* skb->h.uh->source */;
+			sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
+			memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
+			msg->msg_namelen = sizeof(*sin);
+		}
+
+		if (inet_cmsg_flags(isk))
+			ip_cmsg_recv(msg, skb);
+
+#if IS_ENABLED(CONFIG_IPV6)
+	} else if (family == AF_INET6) {
+		struct ipv6hdr *ip6 = ipv6_hdr(skb);
+		DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name);
+
+		if (sin6) {
+			sin6->sin6_family = AF_INET6;
+			sin6->sin6_port = 0;
+			sin6->sin6_addr = ip6->saddr;
+			sin6->sin6_flowinfo = 0;
+			if (inet6_test_bit(SNDFLOW, sk))
+				sin6->sin6_flowinfo = ip6_flowinfo(ip6);
+			sin6->sin6_scope_id =
+				ipv6_iface_scope_id(&sin6->sin6_addr,
+						    inet6_iif(skb));
+			msg->msg_namelen = sizeof(*sin6);
+		}
+
+		if (inet6_sk(sk)->rxopt.all)
+			pingv6_ops.ip6_datagram_recv_common_ctl(sk, msg, skb);
+		if (skb->protocol == htons(ETH_P_IPV6) &&
+		    inet6_sk(sk)->rxopt.all)
+			pingv6_ops.ip6_datagram_recv_specific_ctl(sk, msg, skb);
+		else if (skb->protocol == htons(ETH_P_IP) &&
+			 inet_cmsg_flags(isk))
+			ip_cmsg_recv(msg, skb);
+#endif
+	} else {
+		BUG();
+	}
+
+	err = copied;
+
+done:
+	skb_free_datagram(sk, skb);
+out:
+	pr_debug("ping_recvmsg -> %d\n", err);
+	return err;
+}
+
+static enum skb_drop_reason __ping_queue_rcv_skb(struct sock *sk,
+						 struct sk_buff *skb)
+{
+	enum skb_drop_reason reason;
+
+	pr_debug("ping_queue_rcv_skb(sk=%p,sk->num=%d,skb=%p)\n",
+		 inet_sk(sk), inet_sk(sk)->inet_num, skb);
+	reason = sock_queue_rcv_skb_reason(sk, skb);
+	if (reason) {
+		sk_skb_reason_drop(sk, skb, reason);
+		pr_debug("ping_queue_rcv_skb -> failed\n");
+		return reason;
+	}
+	return SKB_NOT_DROPPED_YET;
+}
+
+int ping_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
+{
+	return __ping_queue_rcv_skb(sk, skb) ? -1 : 0;
+}
+
+
+/*
+ *	All we need to do is get the socket.
+ */
+
+enum skb_drop_reason ping_rcv(struct sk_buff *skb)
+{
+	struct net *net = dev_net(skb->dev);
+	struct icmphdr *icmph = icmp_hdr(skb);
+	struct sock *sk;
+
+	/* We assume the packet has already been checked by icmp_rcv */
+
+	pr_debug("ping_rcv(skb=%p,id=%04x,seq=%04x)\n",
+		 skb, ntohs(icmph->un.echo.id), ntohs(icmph->un.echo.sequence));
+
+	/* Push ICMP header back */
+	skb_push(skb, skb->data - (u8 *)icmph);
+
+	sk = ping_lookup(net, skb, ntohs(icmph->un.echo.id));
+	if (sk)
+		return __ping_queue_rcv_skb(sk, skb);
+
+	kfree_skb_reason(skb, SKB_DROP_REASON_NO_SOCKET);
+	return SKB_DROP_REASON_NO_SOCKET;
+}
+
+struct proto ping_prot = {
+	.name =		"PING",
+	.owner =	THIS_MODULE,
+	.init =		ping_init_sock,
+	.close =	ping_close,
+	.pre_connect =	ping_pre_connect,
+	.connect =	ip4_datagram_connect,
+	.disconnect =	__udp_disconnect,
+	.setsockopt =	ip_setsockopt,
+	.getsockopt =	ip_getsockopt,
+	.sendmsg =	ping_v4_sendmsg,
+	.recvmsg =	ping_recvmsg,
+	.bind =		ping_bind,
+	.backlog_rcv =	ping_queue_rcv_skb,
+	.release_cb =	ip4_datagram_release_cb,
+	.unhash =	ping_unhash,
+	.get_port =	ping_get_port,
+	.put_port =	ping_unhash,
+	.obj_size =	sizeof(struct inet_sock),
+};
+
+#ifdef CONFIG_PROC_FS
+
+static struct sock *ping_get_first(struct seq_file *seq, int start)
+{
+	struct sock *sk;
+	struct ping_iter_state *state = seq->private;
+	struct net *net = seq_file_net(seq);
+
+	for (state->bucket = start; state->bucket < PING_HTABLE_SIZE;
+	     ++state->bucket) {
+		struct hlist_head *hslot;
+
+		hslot = &ping_table.hash[state->bucket];
+
+		if (hlist_empty(hslot))
+			continue;
+
+		sk_for_each(sk, hslot) {
+			if (net_eq(sock_net(sk), net) &&
+			    sk->sk_family == state->family)
+				goto found;
+		}
+	}
+	sk = NULL;
+found:
+	return sk;
+}
+
+static struct sock *ping_get_next(struct seq_file *seq, struct sock *sk)
+{
+	struct ping_iter_state *state = seq->private;
+	struct net *net = seq_file_net(seq);
+
+	do {
+		sk = sk_next(sk);
+	} while (sk && (!net_eq(sock_net(sk), net)));
+
+	if (!sk)
+		return ping_get_first(seq, state->bucket + 1);
+	return sk;
+}
+
+static struct sock *ping_get_idx(struct seq_file *seq, loff_t pos)
+{
+	struct sock *sk = ping_get_first(seq, 0);
+
+	if (sk)
+		while (pos && (sk = ping_get_next(seq, sk)) != NULL)
+			--pos;
+	return pos ? NULL : sk;
+}
+
+void *ping_seq_start(struct seq_file *seq, loff_t *pos, sa_family_t family)
+	__acquires(ping_table.lock)
+{
+	struct ping_iter_state *state = seq->private;
+	state->bucket = 0;
+	state->family = family;
+
+	spin_lock(&ping_table.lock);
+
+	return *pos ? ping_get_idx(seq, *pos-1) : SEQ_START_TOKEN;
+}
+
+static void *ping_v4_seq_start(struct seq_file *seq, loff_t *pos)
+{
+	return ping_seq_start(seq, pos, AF_INET);
+}
+
+void *ping_seq_next(struct seq_file *seq, void *v, loff_t *pos)
+{
+	struct sock *sk;
+
+	if (v == SEQ_START_TOKEN)
+		sk = ping_get_idx(seq, 0);
+	else
+		sk = ping_get_next(seq, v);
+
+	++*pos;
+	return sk;
+}
+
+void ping_seq_stop(struct seq_file *seq, void *v)
+	__releases(ping_table.lock)
+{
+	spin_unlock(&ping_table.lock);
+}
+
+static void ping_v4_format_sock(struct sock *sp, struct seq_file *f,
+		int bucket)
+{
+	struct inet_sock *inet = inet_sk(sp);
+	__be32 dest = inet->inet_daddr;
+	__be32 src = inet->inet_rcv_saddr;
+	__u16 destp = ntohs(inet->inet_dport);
+	__u16 srcp = ntohs(inet->inet_sport);
+
+	seq_printf(f, "%5d: %08X:%04X %08X:%04X"
+		" %02X %08X:%08X %02X:%08lX %08X %5u %8d %llu %d %pK %u",
+		bucket, src, srcp, dest, destp, sp->sk_state,
+		sk_wmem_alloc_get(sp),
+		sk_rmem_alloc_get(sp),
+		0, 0L, 0,
+		from_kuid_munged(seq_user_ns(f), sk_uid(sp)),
+		0, sock_i_ino(sp),
+		refcount_read(&sp->sk_refcnt), sp,
+		sk_drops_read(sp));
+}
+
+static int ping_v4_seq_show(struct seq_file *seq, void *v)
+{
+	seq_setwidth(seq, 127);
+	if (v == SEQ_START_TOKEN)
+		seq_puts(seq, "  sl  local_address rem_address   st tx_queue "
+			   "rx_queue tr tm->when retrnsmt   uid  timeout "
+			   "inode ref pointer drops");
+	else {
+		struct ping_iter_state *state = seq->private;
+
+		ping_v4_format_sock(v, seq, state->bucket);
+	}
+	seq_pad(seq, '\n');
+	return 0;
+}
+
+static const struct seq_operations ping_v4_seq_ops = {
+	.start		= ping_v4_seq_start,
+	.show		= ping_v4_seq_show,
+	.next		= ping_seq_next,
+	.stop		= ping_seq_stop,
+};
+
+static int __net_init ping_v4_proc_init_net(struct net *net)
+{
+	if (!proc_create_net("icmp", 0444, net->proc_net, &ping_v4_seq_ops,
+			sizeof(struct ping_iter_state)))
+		return -ENOMEM;
+
+	net->ipv4.ping_port_rover = get_random_u16();
+	return 0;
+}
+
+static void __net_exit ping_v4_proc_exit_net(struct net *net)
+{
+	remove_proc_entry("icmp", net->proc_net);
+}
+
+static struct pernet_operations ping_v4_net_ops = {
+	.init = ping_v4_proc_init_net,
+	.exit = ping_v4_proc_exit_net,
+};
+
+int __init ping_proc_init(void)
+{
+	return register_pernet_subsys(&ping_v4_net_ops);
+}
+
+void ping_proc_exit(void)
+{
+	unregister_pernet_subsys(&ping_v4_net_ops);
+}
+
+#endif
+
+void __init ping_init(void)
+{
+	int i;
+
+	for (i = 0; i < PING_HTABLE_SIZE; i++)
+		INIT_HLIST_HEAD(&ping_table.hash[i]);
+	spin_lock_init(&ping_table.lock);
+}