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>

3 files changed, 13 insertions, 13 deletions

diff --git a/net/netfilter/ipvs/ip_vs_ctl.c b/net/netfilter/ipvs/ip_vs_ctl.c
index 4af83f466dfc..bcac316addab 100644
--- a/net/netfilter/ipvs/ip_vs_ctl.c
+++ b/net/netfilter/ipvs/ip_vs_ctl.c
@@ -2434,7 +2434,7 @@ static void ip_vs_copy_udest_compat(struct ip_vs_dest_user_kern *udest,
 }
 
 static int
-do_ip_vs_set_ctl(struct sock *sk, int cmd, void __user *user, unsigned int len)
+do_ip_vs_set_ctl(struct sock *sk, int cmd, sockptr_t ptr, unsigned int len)
 {
 	struct net *net = sock_net(sk);
 	int ret;
@@ -2458,7 +2458,7 @@ do_ip_vs_set_ctl(struct sock *sk, int cmd, void __user *user, unsigned int len)
 		return -EINVAL;
 	}
 
-	if (copy_from_user(arg, user, len) != 0)
+	if (copy_from_sockptr(arg, ptr, len) != 0)
 		return -EFAULT;
 
 	/* Handle daemons since they have another lock */
diff --git a/net/netfilter/nf_sockopt.c b/net/netfilter/nf_sockopt.c
index 90469b1f628a..34afcd03b6f6 100644
--- a/net/netfilter/nf_sockopt.c
+++ b/net/netfilter/nf_sockopt.c
@@ -89,7 +89,7 @@ out:
 	return ops;
 }
 
-int nf_setsockopt(struct sock *sk, u_int8_t pf, int val, char __user *opt,
+int nf_setsockopt(struct sock *sk, u_int8_t pf, int val, sockptr_t opt,
 		  unsigned int len)
 {
 	struct nf_sockopt_ops *ops;
diff --git a/net/netfilter/x_tables.c b/net/netfilter/x_tables.c
index 32bab45af7e4..b97eb4b538fd 100644
--- a/net/netfilter/x_tables.c
+++ b/net/netfilter/x_tables.c
@@ -1028,9 +1028,9 @@ int xt_check_target(struct xt_tgchk_param *par,
 EXPORT_SYMBOL_GPL(xt_check_target);
 
 /**
- * xt_copy_counters_from_user - copy counters and metadata from userspace
+ * xt_copy_counters - copy counters and metadata from a sockptr_t
  *
- * @user: src pointer to userspace memory
+ * @arg: src sockptr
  * @len: alleged size of userspace memory
  * @info: where to store the xt_counters_info metadata
  *
@@ -1047,8 +1047,8 @@ EXPORT_SYMBOL_GPL(xt_check_target);
  * Return: returns pointer that caller has to test via IS_ERR().
  * If IS_ERR is false, caller has to vfree the pointer.
  */
-void *xt_copy_counters_from_user(const void __user *user, unsigned int len,
-				 struct xt_counters_info *info)
+void *xt_copy_counters(sockptr_t arg, unsigned int len,
+		       struct xt_counters_info *info)
 {
 	void *mem;
 	u64 size;
@@ -1062,12 +1062,12 @@ void *xt_copy_counters_from_user(const void __user *user, unsigned int len,
 			return ERR_PTR(-EINVAL);
 
 		len -= sizeof(compat_tmp);
-		if (copy_from_user(&compat_tmp, user, sizeof(compat_tmp)) != 0)
+		if (copy_from_sockptr(&compat_tmp, arg, sizeof(compat_tmp)) != 0)
 			return ERR_PTR(-EFAULT);
 
 		memcpy(info->name, compat_tmp.name, sizeof(info->name) - 1);
 		info->num_counters = compat_tmp.num_counters;
-		user += sizeof(compat_tmp);
+		sockptr_advance(arg, sizeof(compat_tmp));
 	} else
 #endif
 	{
@@ -1075,10 +1075,10 @@ void *xt_copy_counters_from_user(const void __user *user, unsigned int len,
 			return ERR_PTR(-EINVAL);
 
 		len -= sizeof(*info);
-		if (copy_from_user(info, user, sizeof(*info)) != 0)
+		if (copy_from_sockptr(info, arg, sizeof(*info)) != 0)
 			return ERR_PTR(-EFAULT);
 
-		user += sizeof(*info);
+		sockptr_advance(arg, sizeof(*info));
 	}
 	info->name[sizeof(info->name) - 1] = '\0';
 
@@ -1092,13 +1092,13 @@ void *xt_copy_counters_from_user(const void __user *user, unsigned int len,
 	if (!mem)
 		return ERR_PTR(-ENOMEM);
 
-	if (copy_from_user(mem, user, len) == 0)
+	if (copy_from_sockptr(mem, arg, len) == 0)
 		return mem;
 
 	vfree(mem);
 	return ERR_PTR(-EFAULT);
 }
-EXPORT_SYMBOL_GPL(xt_copy_counters_from_user);
+EXPORT_SYMBOL_GPL(xt_copy_counters);
 
 #ifdef CONFIG_COMPAT
 int xt_compat_target_offset(const struct xt_target *target)