Merge branch 'get-rid-of-the-address_space-override-in-setsockopt-v2'

Christoph Hellwig says:

====================
get rid of the address_space override in setsockopt v2

setsockopt is the last place in architecture-independ code that still
uses set_fs to force the uaccess routines to operate on kernel pointers.

This series adds a new sockptr_t type that can contained either a kernel
or user pointer, and which has accessors that do the right thing, and
then uses it for setsockopt, starting by refactoring some low-level
helpers and moving them over to it before finally doing the main
setsockopt method.

Note that apparently the eBPF selftests do not even cover this path, so
the series has been tested with a testing patch that always copies the
data first and passes a kernel pointer.  This is something that works for
most common sockopts (and is something that the ePBF support relies on),
but unfortunately in various corner cases we either don't use the passed
in length, or in one case actually copy data back from setsockopt, or in
case of bpfilter straight out do not work with kernel pointers at all.

Against net-next/master.

Changes since v1:
 - check that users don't pass in kernel addresses
 - more bpfilter cleanups
 - cosmetic mptcp tweak
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 20 insertions, 19 deletions

diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index c240fb5de3f0..0b8160d1a6e0 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -1536,7 +1536,7 @@ static void __fanout_set_data_bpf(struct packet_fanout *f, struct bpf_prog *new)
 	}
 }
 
-static int fanout_set_data_cbpf(struct packet_sock *po, char __user *data,
+static int fanout_set_data_cbpf(struct packet_sock *po, sockptr_t data,
 				unsigned int len)
 {
 	struct bpf_prog *new;
@@ -1558,7 +1558,7 @@ static int fanout_set_data_cbpf(struct packet_sock *po, char __user *data,
 	return 0;
 }
 
-static int fanout_set_data_ebpf(struct packet_sock *po, char __user *data,
+static int fanout_set_data_ebpf(struct packet_sock *po, sockptr_t data,
 				unsigned int len)
 {
 	struct bpf_prog *new;
@@ -1568,7 +1568,7 @@ static int fanout_set_data_ebpf(struct packet_sock *po, char __user *data,
 		return -EPERM;
 	if (len != sizeof(fd))
 		return -EINVAL;
-	if (copy_from_user(&fd, data, len))
+	if (copy_from_sockptr(&fd, data, len))
 		return -EFAULT;
 
 	new = bpf_prog_get_type(fd, BPF_PROG_TYPE_SOCKET_FILTER);
@@ -1579,7 +1579,7 @@ static int fanout_set_data_ebpf(struct packet_sock *po, char __user *data,
 	return 0;
 }
 
-static int fanout_set_data(struct packet_sock *po, char __user *data,
+static int fanout_set_data(struct packet_sock *po, sockptr_t data,
 			   unsigned int len)
 {
 	switch (po->fanout->type) {
@@ -3652,7 +3652,8 @@ static void packet_flush_mclist(struct sock *sk)
 }
 
 static int
-packet_setsockopt(struct socket *sock, int level, int optname, char __user *optval, unsigned int optlen)
+packet_setsockopt(struct socket *sock, int level, int optname, sockptr_t optval,
+		  unsigned int optlen)
 {
 	struct sock *sk = sock->sk;
 	struct packet_sock *po = pkt_sk(sk);
@@ -3672,7 +3673,7 @@ packet_setsockopt(struct socket *sock, int level, int optname, char __user *optv
 			return -EINVAL;
 		if (len > sizeof(mreq))
 			len = sizeof(mreq);
-		if (copy_from_user(&mreq, optval, len))
+		if (copy_from_sockptr(&mreq, optval, len))
 			return -EFAULT;
 		if (len < (mreq.mr_alen + offsetof(struct packet_mreq, mr_address)))
 			return -EINVAL;
@@ -3703,7 +3704,7 @@ packet_setsockopt(struct socket *sock, int level, int optname, char __user *optv
 		if (optlen < len) {
 			ret = -EINVAL;
 		} else {
-			if (copy_from_user(&req_u.req, optval, len))
+			if (copy_from_sockptr(&req_u.req, optval, len))
 				ret = -EFAULT;
 			else
 				ret = packet_set_ring(sk, &req_u, 0,
@@ -3718,7 +3719,7 @@ packet_setsockopt(struct socket *sock, int level, int optname, char __user *optv
 
 		if (optlen != sizeof(val))
 			return -EINVAL;
-		if (copy_from_user(&val, optval, sizeof(val)))
+		if (copy_from_sockptr(&val, optval, sizeof(val)))
 			return -EFAULT;
 
 		pkt_sk(sk)->copy_thresh = val;
@@ -3730,7 +3731,7 @@ packet_setsockopt(struct socket *sock, int level, int optname, char __user *optv
 
 		if (optlen != sizeof(val))
 			return -EINVAL;
-		if (copy_from_user(&val, optval, sizeof(val)))
+		if (copy_from_sockptr(&val, optval, sizeof(val)))
 			return -EFAULT;
 		switch (val) {
 		case TPACKET_V1:
@@ -3756,7 +3757,7 @@ packet_setsockopt(struct socket *sock, int level, int optname, char __user *optv
 
 		if (optlen != sizeof(val))
 			return -EINVAL;
-		if (copy_from_user(&val, optval, sizeof(val)))
+		if (copy_from_sockptr(&val, optval, sizeof(val)))
 			return -EFAULT;
 		if (val > INT_MAX)
 			return -EINVAL;
@@ -3776,7 +3777,7 @@ packet_setsockopt(struct socket *sock, int level, int optname, char __user *optv
 
 		if (optlen != sizeof(val))
 			return -EINVAL;
-		if (copy_from_user(&val, optval, sizeof(val)))
+		if (copy_from_sockptr(&val, optval, sizeof(val)))
 			return -EFAULT;
 
 		lock_sock(sk);
@@ -3795,7 +3796,7 @@ packet_setsockopt(struct socket *sock, int level, int optname, char __user *optv
 
 		if (optlen < sizeof(val))
 			return -EINVAL;
-		if (copy_from_user(&val, optval, sizeof(val)))
+		if (copy_from_sockptr(&val, optval, sizeof(val)))
 			return -EFAULT;
 
 		lock_sock(sk);
@@ -3809,7 +3810,7 @@ packet_setsockopt(struct socket *sock, int level, int optname, char __user *optv
 
 		if (optlen < sizeof(val))
 			return -EINVAL;
-		if (copy_from_user(&val, optval, sizeof(val)))
+		if (copy_from_sockptr(&val, optval, sizeof(val)))
 			return -EFAULT;
 
 		lock_sock(sk);
@@ -3825,7 +3826,7 @@ packet_setsockopt(struct socket *sock, int level, int optname, char __user *optv
 			return -EINVAL;
 		if (optlen < sizeof(val))
 			return -EINVAL;
-		if (copy_from_user(&val, optval, sizeof(val)))
+		if (copy_from_sockptr(&val, optval, sizeof(val)))
 			return -EFAULT;
 
 		lock_sock(sk);
@@ -3844,7 +3845,7 @@ packet_setsockopt(struct socket *sock, int level, int optname, char __user *optv
 
 		if (optlen != sizeof(val))
 			return -EINVAL;
-		if (copy_from_user(&val, optval, sizeof(val)))
+		if (copy_from_sockptr(&val, optval, sizeof(val)))
 			return -EFAULT;
 
 		po->tp_tstamp = val;
@@ -3856,7 +3857,7 @@ packet_setsockopt(struct socket *sock, int level, int optname, char __user *optv
 
 		if (optlen != sizeof(val))
 			return -EINVAL;
-		if (copy_from_user(&val, optval, sizeof(val)))
+		if (copy_from_sockptr(&val, optval, sizeof(val)))
 			return -EFAULT;
 
 		return fanout_add(sk, val & 0xffff, val >> 16);
@@ -3874,7 +3875,7 @@ packet_setsockopt(struct socket *sock, int level, int optname, char __user *optv
 
 		if (optlen != sizeof(val))
 			return -EINVAL;
-		if (copy_from_user(&val, optval, sizeof(val)))
+		if (copy_from_sockptr(&val, optval, sizeof(val)))
 			return -EFAULT;
 		if (val < 0 || val > 1)
 			return -EINVAL;
@@ -3888,7 +3889,7 @@ packet_setsockopt(struct socket *sock, int level, int optname, char __user *optv
 
 		if (optlen != sizeof(val))
 			return -EINVAL;
-		if (copy_from_user(&val, optval, sizeof(val)))
+		if (copy_from_sockptr(&val, optval, sizeof(val)))
 			return -EFAULT;
 
 		lock_sock(sk);
@@ -3907,7 +3908,7 @@ packet_setsockopt(struct socket *sock, int level, int optname, char __user *optv
 
 		if (optlen != sizeof(val))
 			return -EINVAL;
-		if (copy_from_user(&val, optval, sizeof(val)))
+		if (copy_from_sockptr(&val, optval, sizeof(val)))
 			return -EFAULT;
 
 		po->xmit = val ? packet_direct_xmit : dev_queue_xmit;