net: rework recvmsg handler msg_name and msg_namelen logic

[ Upstream commit f3d3342602f8bcbf37d7c46641cb9bca7618eb1c ]

This patch now always passes msg->msg_namelen as 0. recvmsg handlers must
set msg_namelen to the proper size <= sizeof(struct sockaddr_storage)
to return msg_name to the user.

This prevents numerous uninitialized memory leaks we had in the
recvmsg handlers and makes it harder for new code to accidentally leak
uninitialized memory.

Optimize for the case recvfrom is called with NULL as address. We don't
need to copy the address at all, so set it to NULL before invoking the
recvmsg handler. We can do so, because all the recvmsg handlers must
cope with the case a plain read() is called on them. read() also sets
msg_name to NULL.

Also document these changes in include/linux/net.h as suggested by David
Miller.

Changes since RFC:

Set msg->msg_name = NULL if user specified a NULL in msg_name but had a
non-null msg_namelen in verify_iovec/verify_compat_iovec. This doesn't
affect sendto as it would bail out earlier while trying to copy-in the
address. It also more naturally reflects the logic by the callers of
verify_iovec.

With this change in place I could remove "
if (!uaddr || msg_sys->msg_namelen == 0)
	msg->msg_name = NULL
".

This change does not alter the user visible error logic as we ignore
msg_namelen as long as msg_name is NULL.

Also remove two unnecessary curly brackets in ___sys_recvmsg and change
comments to netdev style.

Cc: David Miller <davem@davemloft.net>
Suggested-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/crypto/algif_hash.c b/crypto/algif_hash.c
index 2a5af950ba70caac41171a5481ee557c07d0e89a..850246206b1258a697f83e86c39acc9b0a17f973 100644 (file)
--- a/crypto/algif_hash.c
+++ b/crypto/algif_hash.c
@@ -164,8 +164,6 @@ static int hash_recvmsg(struct kiocb *unused, struct socket *sock,
        else if (len < ds)
                msg->msg_flags |= MSG_TRUNC;
 
-       msg->msg_namelen = 0;
-
        lock_sock(sk);
        if (ctx->more) {
                ctx->more = 0;

diff --git a/crypto/algif_skcipher.c b/crypto/algif_skcipher.c
index 07641371d4751a0bffef32af47382fe6b8a44df7..a19c027b29bde504ac8eae4b4572947a69ed2335 100644 (file)
--- a/crypto/algif_skcipher.c
+++ b/crypto/algif_skcipher.c
@@ -435,7 +435,6 @@ static int skcipher_recvmsg(struct kiocb *unused, struct socket *sock,
        long copied = 0;
 
        lock_sock(sk);
-       msg->msg_namelen = 0;
        for (iov = msg->msg_iov, iovlen = msg->msg_iovlen; iovlen > 0;
             iovlen--, iov++) {
                unsigned long seglen = iov->iov_len;

diff --git a/drivers/isdn/mISDN/socket.c b/drivers/isdn/mISDN/socket.c
index 738ea8dd0adfdd113134eff884dfd6c62cebc494..98e8274b26e461c976ae7dffb89afae47fc7ff61 100644 (file)
--- a/drivers/isdn/mISDN/socket.c
+++ b/drivers/isdn/mISDN/socket.c
@@ -117,7 +117,6 @@ mISDN_sock_recvmsg(struct kiocb *iocb, struct socket *sock,
 {
        struct sk_buff          *skb;
        struct sock             *sk = sock->sk;
-       struct sockaddr_mISDN   *maddr;
 
        int             copied, err;
 
@@ -135,9 +134,9 @@ mISDN_sock_recvmsg(struct kiocb *iocb, struct socket *sock,
        if (!skb)
                return err;
 
-       if (msg->msg_namelen >= sizeof(struct sockaddr_mISDN)) {
-               msg->msg_namelen = sizeof(struct sockaddr_mISDN);
-               maddr = (struct sockaddr_mISDN *)msg->msg_name;
+       if (msg->msg_name) {
+               struct sockaddr_mISDN *maddr = msg->msg_name;
+
                maddr->family = AF_ISDN;
                maddr->dev = _pms(sk)->dev->id;
                if ((sk->sk_protocol == ISDN_P_LAPD_TE) ||
@@ -150,11 +149,7 @@ mISDN_sock_recvmsg(struct kiocb *iocb, struct socket *sock,
                        maddr->sapi = _pms(sk)->ch.addr & 0xFF;
                        maddr->tei =  (_pms(sk)->ch.addr >> 8) & 0xFF;
                }
-       } else {
-               if (msg->msg_namelen)
-                       printk(KERN_WARNING "%s: too small namelen %d\n",
-                           __func__, msg->msg_namelen);
-               msg->msg_namelen = 0;
+               msg->msg_namelen = sizeof(*maddr);
        }
 
        copied = skb->len + MISDN_HEADER_LEN;

diff --git a/drivers/net/ppp/pppoe.c b/drivers/net/ppp/pppoe.c
index 11615842a57bd9b5211f8f23c78b2c8248f16a03..2f319d1cdd0d71a6fc626eff6357a48a0d11ff84 100644 (file)
--- a/drivers/net/ppp/pppoe.c
+++ b/drivers/net/ppp/pppoe.c
@@ -985,8 +985,6 @@ static int pppoe_recvmsg(struct kiocb *iocb, struct socket *sock,
        if (error < 0)
                goto end;
 
-       m->msg_namelen = 0;
-
        if (skb) {
                total_len = min_t(size_t, total_len, skb->len);
                error = skb_copy_datagram_iovec(skb, 0, m->msg_iov, total_len);

diff --git a/include/linux/net.h b/include/linux/net.h
index b7ca08e1d993f2b2e76c04473b3e689f3749d8b8..bd4f6c7205101d9027a302efe0c92915c74a109e 100644 (file)
--- a/include/linux/net.h
+++ b/include/linux/net.h
@@ -197,6 +197,14 @@ struct proto_ops {
 #endif
        int             (*sendmsg)   (struct kiocb *iocb, struct socket *sock,
                                      struct msghdr *m, size_t total_len);
+       /* Notes for implementing recvmsg:
+        * ===============================
+        * msg->msg_namelen should get updated by the recvmsg handlers
+        * iff msg_name != NULL. It is by default 0 to prevent
+        * returning uninitialized memory to user space.  The recvfrom
+        * handlers can assume that msg.msg_name is either NULL or has
+        * a minimum size of sizeof(struct sockaddr_storage).
+        */
        int             (*recvmsg)   (struct kiocb *iocb, struct socket *sock,
                                      struct msghdr *m, size_t total_len,
                                      int flags);

diff --git a/net/appletalk/ddp.c b/net/appletalk/ddp.c
index bfa9ab93eda566458dcf6fdf72646009e0748548..334d4cd7612f677afb44ae1a3d1fd244d37ae984 100644 (file)
--- a/net/appletalk/ddp.c
+++ b/net/appletalk/ddp.c
@@ -1740,7 +1740,6 @@ static int atalk_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr
                         size_t size, int flags)
 {
        struct sock *sk = sock->sk;
-       struct sockaddr_at *sat = (struct sockaddr_at *)msg->msg_name;
        struct ddpehdr *ddp;
        int copied = 0;
        int offset = 0;
@@ -1769,14 +1768,13 @@ static int atalk_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr
        }
        err = skb_copy_datagram_iovec(skb, offset, msg->msg_iov, copied);
 
-       if (!err) {
-               if (sat) {
-                       sat->sat_family      = AF_APPLETALK;
-                       sat->sat_port        = ddp->deh_sport;
-                       sat->sat_addr.s_node = ddp->deh_snode;
-                       sat->sat_addr.s_net  = ddp->deh_snet;
-               }
-               msg->msg_namelen = sizeof(*sat);
+       if (!err && msg->msg_name) {
+               struct sockaddr_at *sat = msg->msg_name;
+               sat->sat_family      = AF_APPLETALK;
+               sat->sat_port        = ddp->deh_sport;
+               sat->sat_addr.s_node = ddp->deh_snode;
+               sat->sat_addr.s_net  = ddp->deh_snet;
+               msg->msg_namelen     = sizeof(*sat);
        }
 
        skb_free_datagram(sk, skb);     /* Free the datagram. */

diff --git a/net/atm/common.c b/net/atm/common.c
index 43b6bfed036ca71b698b286b5b36a7e982717d47..0ca06e851e7c4ef43403b17f926c7f8457e2fe42 100644 (file)
--- a/net/atm/common.c
+++ b/net/atm/common.c
@@ -500,8 +500,6 @@ int vcc_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
        struct sk_buff *skb;
        int copied, error = -EINVAL;
 
-       msg->msg_namelen = 0;
-
        if (sock->state != SS_CONNECTED)
                return -ENOTCONN;
        if (flags & ~MSG_DONTWAIT)              /* only handle MSG_DONTWAIT */

diff --git a/net/ax25/af_ax25.c b/net/ax25/af_ax25.c
index 86ac37f8e2272a5028906621cf61d136db6b8c5b..7b8db0ede163b578a1bb989c66d2260a8e02462d 100644 (file)
--- a/net/ax25/af_ax25.c
+++ b/net/ax25/af_ax25.c
@@ -1635,11 +1635,11 @@ static int ax25_recvmsg(struct kiocb *iocb, struct socket *sock,
 
        skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
 
-       if (msg->msg_namelen != 0) {
-               struct sockaddr_ax25 *sax = (struct sockaddr_ax25 *)msg->msg_name;
+       if (msg->msg_name) {
                ax25_digi digi;
                ax25_address src;
                const unsigned char *mac = skb_mac_header(skb);
+               struct sockaddr_ax25 *sax = msg->msg_name;
 
                memset(sax, 0, sizeof(struct full_sockaddr_ax25));
                ax25_addr_parse(mac + 1, skb->data - mac - 1, &src, NULL,

diff --git a/net/bluetooth/af_bluetooth.c b/net/bluetooth/af_bluetooth.c
index 838f113bfdd9be00912777d6e656c7536ba8acfd..0938f6b505e152cb6e24aeeeb12e76f605386892 100644 (file)
--- a/net/bluetooth/af_bluetooth.c
+++ b/net/bluetooth/af_bluetooth.c
@@ -245,8 +245,6 @@ int bt_sock_recvmsg(struct kiocb *iocb, struct socket *sock,
        if (flags & (MSG_OOB))
                return -EOPNOTSUPP;
 
-       msg->msg_namelen = 0;
-
        skb = skb_recv_datagram(sk, flags, noblock, &err);
        if (!skb) {
                if (sk->sk_shutdown & RCV_SHUTDOWN)
@@ -311,8 +309,6 @@ int bt_sock_stream_recvmsg(struct kiocb *iocb, struct socket *sock,
        if (flags & MSG_OOB)
                return -EOPNOTSUPP;
 
-       msg->msg_namelen = 0;
-
        BT_DBG("sk %p size %zu", sk, size);
 
        lock_sock(sk);

diff --git a/net/bluetooth/hci_sock.c b/net/bluetooth/hci_sock.c
index 8361ee40aec4792874682952220b6677a276afd2..bb78c754a5ae016a45f582ebe5292105f0f89537 100644 (file)
--- a/net/bluetooth/hci_sock.c
+++ b/net/bluetooth/hci_sock.c
@@ -448,8 +448,6 @@ static int hci_sock_recvmsg(struct kiocb *iocb, struct socket *sock,
        if (!skb)
                return err;
 
-       msg->msg_namelen = 0;
-
        copied = skb->len;
        if (len < copied) {
                msg->msg_flags |= MSG_TRUNC;

diff --git a/net/bluetooth/rfcomm/sock.c b/net/bluetooth/rfcomm/sock.c
index 82ce164c29faa5b02d243b1dddb57f2b31da6de8..14c48647958bd73de1d5f9ff6985f10fb0db8d19 100644 (file)
--- a/net/bluetooth/rfcomm/sock.c
+++ b/net/bluetooth/rfcomm/sock.c
@@ -627,7 +627,6 @@ static int rfcomm_sock_recvmsg(struct kiocb *iocb, struct socket *sock,
 
        if (test_and_clear_bit(RFCOMM_DEFER_SETUP, &d->flags)) {
                rfcomm_dlc_accept(d);
-               msg->msg_namelen = 0;
                return 0;
        }
 

diff --git a/net/caif/caif_socket.c b/net/caif/caif_socket.c
index 53a8e37d020a3f1cbe28b4de9f5ce006380d8f50..7fac75f6fcfbd0764198bf79f70ecd46e53d7e56 100644 (file)
--- a/net/caif/caif_socket.c
+++ b/net/caif/caif_socket.c
@@ -320,8 +320,6 @@ static int caif_seqpkt_recvmsg(struct kiocb *iocb, struct socket *sock,
        if (m->msg_flags&MSG_OOB)
                goto read_error;
 
-       m->msg_namelen = 0;
-
        skb = skb_recv_datagram(sk, flags, 0 , &ret);
        if (!skb)
                goto read_error;
@@ -395,8 +393,6 @@ static int caif_stream_recvmsg(struct kiocb *iocb, struct socket *sock,
        if (flags&MSG_OOB)
                goto out;
 
-       msg->msg_namelen = 0;
-
        /*
         * Lock the socket to prevent queue disordering
         * while sleeps in memcpy_tomsg

diff --git a/net/compat.c b/net/compat.c
index 3139ef298145f8fc42329ae625c289a8cd690e00..3312574e1cf6218281e68be721982c678412c40a 100644 (file)
--- a/net/compat.c
+++ b/net/compat.c
@@ -93,7 +93,8 @@ int verify_compat_iovec(struct msghdr *kern_msg, struct iovec *kern_iov,
                        if (err < 0)
                                return err;
                }
-               kern_msg->msg_name = kern_address;
+               if (kern_msg->msg_name)
+                       kern_msg->msg_name = kern_address;
        } else
                kern_msg->msg_name = NULL;
 

diff --git a/net/core/iovec.c b/net/core/iovec.c
index c40f27e7d2089f713f5e2dac80d0940a7095156a..139ef937a9098f6c8f0a8d85f7e500d70ff431dd 100644 (file)
--- a/net/core/iovec.c
+++ b/net/core/iovec.c
@@ -48,7 +48,8 @@ int verify_iovec(struct msghdr *m, struct iovec *iov, struct sockaddr *address,
                        if (err < 0)
                                return err;
                }
-               m->msg_name = address;
+               if (m->msg_name)
+                       m->msg_name = address;
        } else {
                m->msg_name = NULL;
        }

diff --git a/net/ipx/af_ipx.c b/net/ipx/af_ipx.c
index 9680226640ef783c164618f2f2f8fd5504259f4a..8c06a506577228bbccd1a92b1d74038a02d705fd 100644 (file)
--- a/net/ipx/af_ipx.c
+++ b/net/ipx/af_ipx.c
@@ -1835,8 +1835,6 @@ static int ipx_recvmsg(struct kiocb *iocb, struct socket *sock,
        if (skb->tstamp.tv64)
                sk->sk_stamp = skb->tstamp;
 
-       msg->msg_namelen = sizeof(*sipx);
-
        if (sipx) {
                sipx->sipx_family       = AF_IPX;
                sipx->sipx_port         = ipx->ipx_source.sock;
@@ -1844,6 +1842,7 @@ static int ipx_recvmsg(struct kiocb *iocb, struct socket *sock,
                sipx->sipx_network      = IPX_SKB_CB(skb)->ipx_source_net;
                sipx->sipx_type         = ipx->ipx_type;
                sipx->sipx_zero         = 0;
+               msg->msg_namelen        = sizeof(*sipx);
        }
        rc = copied;
 

diff --git a/net/irda/af_irda.c b/net/irda/af_irda.c
index 91821e96dcec1c1a65707a01a7a0f573040e3388..f5d011ad469409f4bcd73cb9ac6c512bbcbce4e8 100644 (file)
--- a/net/irda/af_irda.c
+++ b/net/irda/af_irda.c
@@ -1386,8 +1386,6 @@ static int irda_recvmsg_dgram(struct kiocb *iocb, struct socket *sock,
 
        IRDA_DEBUG(4, "%s()\n", __func__);
 
-       msg->msg_namelen = 0;
-
        skb = skb_recv_datagram(sk, flags & ~MSG_DONTWAIT,
                                flags & MSG_DONTWAIT, &err);
        if (!skb)
@@ -1452,8 +1450,6 @@ static int irda_recvmsg_stream(struct kiocb *iocb, struct socket *sock,
        target = sock_rcvlowat(sk, flags & MSG_WAITALL, size);
        timeo = sock_rcvtimeo(sk, noblock);
 
-       msg->msg_namelen = 0;
-
        do {
                int chunk;
                struct sk_buff *skb = skb_dequeue(&sk->sk_receive_queue);

diff --git a/net/iucv/af_iucv.c b/net/iucv/af_iucv.c
index e836140c75fbf76452ed0f11881f95bf8aef2e67..cf98d625d9585857fc0387200bb69cf380760f82 100644 (file)
--- a/net/iucv/af_iucv.c
+++ b/net/iucv/af_iucv.c
@@ -1356,8 +1356,6 @@ static int iucv_sock_recvmsg(struct kiocb *iocb, struct socket *sock,
        int blen;
        int err = 0;
 
-       msg->msg_namelen = 0;
-
        if ((sk->sk_state == IUCV_DISCONN || sk->sk_state == IUCV_SEVERED) &&
            skb_queue_empty(&iucv->backlog_skb_q) &&
            skb_queue_empty(&sk->sk_receive_queue) &&

diff --git a/net/key/af_key.c b/net/key/af_key.c
index 8dbdb8e7dbe15c087c509e74df91c1298d34b217..dc8d7efefa6c73b68948bb3e464dcbfefbccb23d 100644 (file)
--- a/net/key/af_key.c
+++ b/net/key/af_key.c
@@ -3595,7 +3595,6 @@ static int pfkey_recvmsg(struct kiocb *kiocb,
        if (flags & ~(MSG_PEEK|MSG_DONTWAIT|MSG_TRUNC|MSG_CMSG_COMPAT))
                goto out;
 
-       msg->msg_namelen = 0;
        skb = skb_recv_datagram(sk, flags, flags & MSG_DONTWAIT, &err);
        if (skb == NULL)
                goto out;

diff --git a/net/l2tp/l2tp_ppp.c b/net/l2tp/l2tp_ppp.c
index 85700795af0397fb1eb4d424c8b78634bbb4da60..969cd3eacd2b3121dabc59584d87b275d5fab7d9 100644 (file)
--- a/net/l2tp/l2tp_ppp.c
+++ b/net/l2tp/l2tp_ppp.c
@@ -200,8 +200,6 @@ static int pppol2tp_recvmsg(struct kiocb *iocb, struct socket *sock,
        if (sk->sk_state & PPPOX_BOUND)
                goto end;
 
-       msg->msg_namelen = 0;
-
        err = 0;
        skb = skb_recv_datagram(sk, flags & ~MSG_DONTWAIT,
                                flags & MSG_DONTWAIT, &err);

diff --git a/net/llc/af_llc.c b/net/llc/af_llc.c
index e5565c71cbbb5d9889c3f644ae1d00f8d1708287..99a60d545b2488840afe25255366f48c45a9ba44 100644 (file)
--- a/net/llc/af_llc.c
+++ b/net/llc/af_llc.c
@@ -720,8 +720,6 @@ static int llc_ui_recvmsg(struct kiocb *iocb, struct socket *sock,
        int target;     /* Read at least this many bytes */
        long timeo;
 
-       msg->msg_namelen = 0;
-
        lock_sock(sk);
        copied = -ENOTCONN;
        if (unlikely(sk->sk_type == SOCK_STREAM && sk->sk_state == TCP_LISTEN))

diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index 3d1d55ded4f9c503b382abf0c7e3f768b6173320..2369e9620aa4c9b9012ad172ef2171aa608e0666 100644 (file)
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -1445,8 +1445,6 @@ static int netlink_recvmsg(struct kiocb *kiocb, struct socket *sock,
        }
 #endif
 
-       msg->msg_namelen = 0;
-
        copied = data_skb->len;
        if (len < copied) {
                msg->msg_flags |= MSG_TRUNC;

diff --git a/net/netrom/af_netrom.c b/net/netrom/af_netrom.c
index 3df7c5a4ac8ee1c955777a064cf879e57f489347..b4d889b589b0d072c64e3b5d7b3c04c65ddb6136 100644 (file)
--- a/net/netrom/af_netrom.c
+++ b/net/netrom/af_netrom.c
@@ -1182,10 +1182,9 @@ static int nr_recvmsg(struct kiocb *iocb, struct socket *sock,
                sax->sax25_family = AF_NETROM;
                skb_copy_from_linear_data_offset(skb, 7, sax->sax25_call.ax25_call,
                              AX25_ADDR_LEN);
+               msg->msg_namelen = sizeof(*sax);
        }
 
-       msg->msg_namelen = sizeof(*sax);
-
        skb_free_datagram(sk, skb);
 
        release_sock(sk);

diff --git a/net/nfc/rawsock.c b/net/nfc/rawsock.c
index 7a167fce319c0e28960a9447b290ae6cfdc4c656..0d570d304da224df3d65591695a454946ccc442b 100644 (file)
--- a/net/nfc/rawsock.c
+++ b/net/nfc/rawsock.c
@@ -248,8 +248,6 @@ static int rawsock_recvmsg(struct kiocb *iocb, struct socket *sock,
        if (!skb)
                return rc;
 
-       msg->msg_namelen = 0;
-
        copied = skb->len;
        if (len < copied) {
                msg->msg_flags |= MSG_TRUNC;

diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index a2ac2c37939cdfe8c208410b8421a6552dd93f45..74db1cbc79ad121d7ab3e0e54979515f39ff979e 100644 (file)
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -2663,7 +2663,6 @@ static int packet_recvmsg(struct kiocb *iocb, struct socket *sock,
        struct sock *sk = sock->sk;
        struct sk_buff *skb;
        int copied, err;
-       struct sockaddr_ll *sll;
        int vnet_hdr_len = 0;
 
        err = -EINVAL;
@@ -2746,22 +2745,10 @@ static int packet_recvmsg(struct kiocb *iocb, struct socket *sock,
                        goto out_free;
        }
 
-       /*
-        *      If the address length field is there to be filled in, we fill
-        *      it in now.
-        */
-
-       sll = &PACKET_SKB_CB(skb)->sa.ll;
-       if (sock->type == SOCK_PACKET)
-               msg->msg_namelen = sizeof(struct sockaddr_pkt);
-       else
-               msg->msg_namelen = sll->sll_halen + offsetof(struct sockaddr_ll, sll_addr);
-
-       /*
-        *      You lose any data beyond the buffer you gave. If it worries a
-        *      user program they can ask the device for its MTU anyway.
+       /* You lose any data beyond the buffer you gave. If it worries
+        * a user program they can ask the device for its MTU
+        * anyway.
         */
-
        copied = skb->len;
        if (copied > len) {
                copied = len;
@@ -2774,9 +2761,20 @@ static int packet_recvmsg(struct kiocb *iocb, struct socket *sock,
 
        sock_recv_ts_and_drops(msg, sk, skb);
 
-       if (msg->msg_name)
+       if (msg->msg_name) {
+               /* If the address length field is there to be filled
+                * in, we fill it in now.
+                */
+               if (sock->type == SOCK_PACKET) {
+                       msg->msg_namelen = sizeof(struct sockaddr_pkt);
+               } else {
+                       struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll;
+                       msg->msg_namelen = sll->sll_halen +
+                               offsetof(struct sockaddr_ll, sll_addr);
+               }
                memcpy(msg->msg_name, &PACKET_SKB_CB(skb)->sa,
                       msg->msg_namelen);
+       }
 
        if (pkt_sk(sk)->auxdata) {
                struct tpacket_auxdata aux;

diff --git a/net/rds/recv.c b/net/rds/recv.c
index fc57d31676a13b0e1de6d9d7df5606755574d12d..96a1239c05c211286b87e3f8da17df934ab2b680 100644 (file)
--- a/net/rds/recv.c
+++ b/net/rds/recv.c
@@ -410,8 +410,6 @@ int rds_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
 
        rdsdebug("size %zu flags 0x%x timeo %ld\n", size, msg_flags, timeo);
 
-       msg->msg_namelen = 0;
-
        if (msg_flags & MSG_OOB)
                goto out;
 

diff --git a/net/rose/af_rose.c b/net/rose/af_rose.c
index 1f96fb9743b584590843214b5b582d8ebb6a26c9..bf76dec76e00bec4b532f116d4c947e61b128c24 100644 (file)
--- a/net/rose/af_rose.c
+++ b/net/rose/af_rose.c
@@ -1221,7 +1221,6 @@ static int rose_recvmsg(struct kiocb *iocb, struct socket *sock,
 {
        struct sock *sk = sock->sk;
        struct rose_sock *rose = rose_sk(sk);
-       struct sockaddr_rose *srose = (struct sockaddr_rose *)msg->msg_name;
        size_t copied;
        unsigned char *asmptr;
        struct sk_buff *skb;
@@ -1257,8 +1256,11 @@ static int rose_recvmsg(struct kiocb *iocb, struct socket *sock,
 
        skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
 
-       if (srose != NULL) {
-               memset(srose, 0, msg->msg_namelen);
+       if (msg->msg_name) {
+               struct sockaddr_rose *srose;
+
+               memset(msg->msg_name, 0, sizeof(struct full_sockaddr_rose));
+               srose = msg->msg_name;
                srose->srose_family = AF_ROSE;
                srose->srose_addr   = rose->dest_addr;
                srose->srose_call   = rose->dest_call;

diff --git a/net/rxrpc/ar-recvmsg.c b/net/rxrpc/ar-recvmsg.c
index 4b48687c3890fc64c186b797181062a4cc9ac4fa..898492a8d61be8fde5bcdf66084d525bee23b5f0 100644 (file)
--- a/net/rxrpc/ar-recvmsg.c
+++ b/net/rxrpc/ar-recvmsg.c
@@ -143,10 +143,13 @@ int rxrpc_recvmsg(struct kiocb *iocb, struct socket *sock,
 
                /* copy the peer address and timestamp */
                if (!continue_call) {
-                       if (msg->msg_name && msg->msg_namelen > 0)
+                       if (msg->msg_name) {
+                               size_t len =
+                                       sizeof(call->conn->trans->peer->srx);
                                memcpy(msg->msg_name,
-                                      &call->conn->trans->peer->srx,
-                                      sizeof(call->conn->trans->peer->srx));
+                                      &call->conn->trans->peer->srx, len);
+                               msg->msg_namelen = len;
+                       }
                        sock_recv_ts_and_drops(msg, &rx->sk, skb);
                }
 

diff --git a/net/socket.c b/net/socket.c
index bf7adaae4b7f3b53bd4bea27c9bd60d12cc26245..18d478a5e0ac6bd3d0117bc5116d641a365910e3 100644 (file)
--- a/net/socket.c
+++ b/net/socket.c
@@ -1752,8 +1752,10 @@ SYSCALL_DEFINE6(recvfrom, int, fd, void __user *, ubuf, size_t, size,
        msg.msg_iov = &iov;
        iov.iov_len = size;
        iov.iov_base = ubuf;
-       msg.msg_name = (struct sockaddr *)&address;
-       msg.msg_namelen = sizeof(address);
+       /* Save some cycles and don't copy the address if not needed */
+       msg.msg_name = addr ? (struct sockaddr *)&address : NULL;
+       /* We assume all kernel code knows the size of sockaddr_storage */
+       msg.msg_namelen = 0;
        if (sock->file->f_flags & O_NONBLOCK)
                flags |= MSG_DONTWAIT;
        err = sock_recvmsg(sock, &msg, size, flags);
@@ -2142,18 +2144,16 @@ static int ___sys_recvmsg(struct socket *sock, struct msghdr __user *msg,
                        goto out;
        }
 
-       /*
-        *      Save the user-mode address (verify_iovec will change the
-        *      kernel msghdr to use the kernel address space)
+       /* Save the user-mode address (verify_iovec will change the
+        * kernel msghdr to use the kernel address space)
         */
-
        uaddr = (__force void __user *)msg_sys->msg_name;
        uaddr_len = COMPAT_NAMELEN(msg);
-       if (MSG_CMSG_COMPAT & flags) {
+       if (MSG_CMSG_COMPAT & flags)
                err = verify_compat_iovec(msg_sys, iov,
                                          (struct sockaddr *)&addr,
                                          VERIFY_WRITE);
-       } else
+       else
                err = verify_iovec(msg_sys, iov,
                                   (struct sockaddr *)&addr,
                                   VERIFY_WRITE);
@@ -2164,6 +2164,9 @@ static int ___sys_recvmsg(struct socket *sock, struct msghdr __user *msg,
        cmsg_ptr = (unsigned long)msg_sys->msg_control;
        msg_sys->msg_flags = flags & (MSG_CMSG_CLOEXEC|MSG_CMSG_COMPAT);
 
+       /* We assume all kernel code knows the size of sockaddr_storage */
+       msg_sys->msg_namelen = 0;
+
        if (sock->file->f_flags & O_NONBLOCK)
                flags |= MSG_DONTWAIT;
        err = (nosec ? sock_recvmsg_nosec : sock_recvmsg)(sock, msg_sys,

diff --git a/net/tipc/socket.c b/net/tipc/socket.c
index fdf34af436eb481e78dc7935a20dd0721a2ccb40..058941e6c93694efa5a564a42f5f75bede567200 100644 (file)
--- a/net/tipc/socket.c
+++ b/net/tipc/socket.c
@@ -949,9 +949,6 @@ static int recv_msg(struct kiocb *iocb, struct socket *sock,
                goto exit;
        }
 
-       /* will be updated in set_orig_addr() if needed */
-       m->msg_namelen = 0;
-
        timeout = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
 restart:
 
@@ -1078,9 +1075,6 @@ static int recv_stream(struct kiocb *iocb, struct socket *sock,
                goto exit;
        }
 
-       /* will be updated in set_orig_addr() if needed */
-       m->msg_namelen = 0;
-
        target = sock_rcvlowat(sk, flags & MSG_WAITALL, buf_len);
        timeout = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
 restart:

diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index 5122b22540be2c4b36519744d775111f6009181c..9338ccc1a00b07a6a257d831c1cddfe604f32bdc 100644 (file)
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -1744,7 +1744,6 @@ static void unix_copy_addr(struct msghdr *msg, struct sock *sk)
 {
        struct unix_sock *u = unix_sk(sk);
 
-       msg->msg_namelen = 0;
        if (u->addr) {
                msg->msg_namelen = u->addr->len;
                memcpy(msg->msg_name, u->addr->name, u->addr->len);
@@ -1767,8 +1766,6 @@ static int unix_dgram_recvmsg(struct kiocb *iocb, struct socket *sock,
        if (flags&MSG_OOB)
                goto out;
 
-       msg->msg_namelen = 0;
-
        err = mutex_lock_interruptible(&u->readlock);
        if (err) {
                err = sock_intr_errno(sock_rcvtimeo(sk, noblock));
@@ -1902,8 +1899,6 @@ static int unix_stream_recvmsg(struct kiocb *iocb, struct socket *sock,
        target = sock_rcvlowat(sk, flags&MSG_WAITALL, size);
        timeo = sock_rcvtimeo(sk, flags&MSG_DONTWAIT);
 
-       msg->msg_namelen = 0;
-
        /* Lock the socket to prevent queue disordering
         * while sleeps in memcpy_tomsg
         */

diff --git a/net/x25/af_x25.c b/net/x25/af_x25.c
index dc24ba9d5cccf75f0f55e4bf737cb6ea7250936a..07b9973af6a7ab7fb889b88975e91f6953a68397 100644 (file)
--- a/net/x25/af_x25.c
+++ b/net/x25/af_x25.c
@@ -1343,10 +1343,9 @@ static int x25_recvmsg(struct kiocb *iocb, struct socket *sock,
        if (sx25) {
                sx25->sx25_family = AF_X25;
                sx25->sx25_addr   = x25->dest_addr;
+               msg->msg_namelen = sizeof(*sx25);
        }
 
-       msg->msg_namelen = sizeof(struct sockaddr_x25);
-
        x25_check_rbuf(sk);
        rc = copied;
 out_free_dgram: