Merge branch 'uaccess.net' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Al Viro says:

====================
uaccess-related stuff in net/*

Assorted uaccess-related work in net/*.  First, there's
getting rid of compat_alloc_user_space() mess in MCAST_...
[gs]etsockopt() - no need to play with copying to/from temporary
object on userland stack, etc., when ->compat_[sg]etsockopt()
instances in question can easly do everything without that.
That's the first 13 patches.  Then there's a trivial bit in
net/batman-adv (completely unrelated to everything else) and
finally getting the atm compat ioctls into simpler shape.
====================

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

2 files changed, 200 insertions, 50 deletions

diff --git a/net/ipv6/ipv6_sockglue.c b/net/ipv6/ipv6_sockglue.c
index a0e50cc57e54..e10258c2210e 100644
--- a/net/ipv6/ipv6_sockglue.c
+++ b/net/ipv6/ipv6_sockglue.c
@@ -136,6 +136,41 @@ static bool setsockopt_needs_rtnl(int optname)
 	return false;
 }
 
+static int do_ipv6_mcast_group_source(struct sock *sk, int optname,
+				      struct group_source_req *greqs)
+{
+	int omode, add;
+
+	if (greqs->gsr_group.ss_family != AF_INET6 ||
+	    greqs->gsr_source.ss_family != AF_INET6)
+		return -EADDRNOTAVAIL;
+
+	if (optname == MCAST_BLOCK_SOURCE) {
+		omode = MCAST_EXCLUDE;
+		add = 1;
+	} else if (optname == MCAST_UNBLOCK_SOURCE) {
+		omode = MCAST_EXCLUDE;
+		add = 0;
+	} else if (optname == MCAST_JOIN_SOURCE_GROUP) {
+		struct sockaddr_in6 *psin6;
+		int retv;
+
+		psin6 = (struct sockaddr_in6 *)&greqs->gsr_group;
+		retv = ipv6_sock_mc_join_ssm(sk, greqs->gsr_interface,
+					     &psin6->sin6_addr,
+					     MCAST_INCLUDE);
+		/* prior join w/ different source is ok */
+		if (retv && retv != -EADDRINUSE)
+			return retv;
+		omode = MCAST_INCLUDE;
+		add = 1;
+	} else /* MCAST_LEAVE_SOURCE_GROUP */ {
+		omode = MCAST_INCLUDE;
+		add = 0;
+	}
+	return ip6_mc_source(add, omode, sk, greqs);
+}
+
 static int do_ipv6_setsockopt(struct sock *sk, int level, int optname,
 		    char __user *optval, unsigned int optlen)
 {
@@ -715,7 +750,6 @@ done:
 	case MCAST_UNBLOCK_SOURCE:
 	{
 		struct group_source_req greqs;
-		int omode, add;
 
 		if (optlen < sizeof(struct group_source_req))
 			goto e_inval;
@@ -723,34 +757,7 @@ done:
 			retv = -EFAULT;
 			break;
 		}
-		if (greqs.gsr_group.ss_family != AF_INET6 ||
-		    greqs.gsr_source.ss_family != AF_INET6) {
-			retv = -EADDRNOTAVAIL;
-			break;
-		}
-		if (optname == MCAST_BLOCK_SOURCE) {
-			omode = MCAST_EXCLUDE;
-			add = 1;
-		} else if (optname == MCAST_UNBLOCK_SOURCE) {
-			omode = MCAST_EXCLUDE;
-			add = 0;
-		} else if (optname == MCAST_JOIN_SOURCE_GROUP) {
-			struct sockaddr_in6 *psin6;
-
-			psin6 = (struct sockaddr_in6 *)&greqs.gsr_group;
-			retv = ipv6_sock_mc_join_ssm(sk, greqs.gsr_interface,
-						     &psin6->sin6_addr,
-						     MCAST_INCLUDE);
-			/* prior join w/ different source is ok */
-			if (retv && retv != -EADDRINUSE)
-				break;
-			omode = MCAST_INCLUDE;
-			add = 1;
-		} else /* MCAST_LEAVE_SOURCE_GROUP */ {
-			omode = MCAST_INCLUDE;
-			add = 0;
-		}
-		retv = ip6_mc_source(add, omode, sk, &greqs);
+		retv = do_ipv6_mcast_group_source(sk, optname, &greqs);
 		break;
 	}
 	case MCAST_MSFILTER:
@@ -780,7 +787,7 @@ done:
 			retv = -EINVAL;
 			break;
 		}
-		retv = ip6_mc_msfilter(sk, gsf);
+		retv = ip6_mc_msfilter(sk, gsf, gsf->gf_slist);
 		kfree(gsf);
 
 		break;
@@ -973,9 +980,110 @@ int compat_ipv6_setsockopt(struct sock *sk, int level, int optname,
 	if (level != SOL_IPV6)
 		return -ENOPROTOOPT;
 
-	if (optname >= MCAST_JOIN_GROUP && optname <= MCAST_MSFILTER)
-		return compat_mc_setsockopt(sk, level, optname, optval, optlen,
-			ipv6_setsockopt);
+	switch (optname) {
+	case MCAST_JOIN_GROUP:
+	case MCAST_LEAVE_GROUP:
+	{
+		struct compat_group_req __user *gr32 = (void __user *)optval;
+		struct group_req greq;
+		struct sockaddr_in6 *psin6 = (struct sockaddr_in6 *)&greq.gr_group;
+
+		if (optlen < sizeof(struct compat_group_req))
+			return -EINVAL;
+
+		if (get_user(greq.gr_interface, &gr32->gr_interface) ||
+		    copy_from_user(&greq.gr_group, &gr32->gr_group,
+				sizeof(greq.gr_group)))
+			return -EFAULT;
+
+		if (greq.gr_group.ss_family != AF_INET6)
+			return -EADDRNOTAVAIL;
+
+		rtnl_lock();
+		lock_sock(sk);
+		if (optname == MCAST_JOIN_GROUP)
+			err = ipv6_sock_mc_join(sk, greq.gr_interface,
+						 &psin6->sin6_addr);
+		else
+			err = ipv6_sock_mc_drop(sk, greq.gr_interface,
+						 &psin6->sin6_addr);
+		release_sock(sk);
+		rtnl_unlock();
+		return err;
+	}
+	case MCAST_JOIN_SOURCE_GROUP:
+	case MCAST_LEAVE_SOURCE_GROUP:
+	case MCAST_BLOCK_SOURCE:
+	case MCAST_UNBLOCK_SOURCE:
+	{
+		struct compat_group_source_req __user *gsr32 = (void __user *)optval;
+		struct group_source_req greqs;
+
+		if (optlen < sizeof(struct compat_group_source_req))
+			return -EINVAL;
+
+		if (get_user(greqs.gsr_interface, &gsr32->gsr_interface) ||
+		    copy_from_user(&greqs.gsr_group, &gsr32->gsr_group,
+				sizeof(greqs.gsr_group)) ||
+		    copy_from_user(&greqs.gsr_source, &gsr32->gsr_source,
+				sizeof(greqs.gsr_source)))
+			return -EFAULT;
+
+		rtnl_lock();
+		lock_sock(sk);
+		err = do_ipv6_mcast_group_source(sk, optname, &greqs);
+		release_sock(sk);
+		rtnl_unlock();
+		return err;
+	}
+	case MCAST_MSFILTER:
+	{
+		const int size0 = offsetof(struct compat_group_filter, gf_slist);
+		struct compat_group_filter *gf32;
+		void *p;
+		int n;
+
+		if (optlen < size0)
+			return -EINVAL;
+		if (optlen > sysctl_optmem_max - 4)
+			return -ENOBUFS;
+
+		p = kmalloc(optlen + 4, GFP_KERNEL);
+		if (!p)
+			return -ENOMEM;
+
+		gf32 = p + 4; /* we want ->gf_group and ->gf_slist aligned */
+		if (copy_from_user(gf32, optval, optlen)) {
+			err = -EFAULT;
+			goto mc_msf_out;
+		}
+
+		n = gf32->gf_numsrc;
+		/* numsrc >= (4G-140)/128 overflow in 32 bits */
+		if (n >= 0x1ffffffU ||
+		    n > sysctl_mld_max_msf) {
+			err = -ENOBUFS;
+			goto mc_msf_out;
+		}
+		if (offsetof(struct compat_group_filter, gf_slist[n]) > optlen) {
+			err = -EINVAL;
+			goto mc_msf_out;
+		}
+
+		rtnl_lock();
+		lock_sock(sk);
+		err = ip6_mc_msfilter(sk, &(struct group_filter){
+				.gf_interface = gf32->gf_interface,
+				.gf_group = gf32->gf_group,
+				.gf_fmode = gf32->gf_fmode,
+				.gf_numsrc = gf32->gf_numsrc}, gf32->gf_slist);
+		release_sock(sk);
+		rtnl_unlock();
+mc_msf_out:
+		kfree(p);
+		return err;
+	}
+	}
 
 	err = do_ipv6_setsockopt(sk, level, optname, optval, optlen);
 #ifdef CONFIG_NETFILTER
@@ -1048,18 +1156,28 @@ static int do_ipv6_getsockopt(struct sock *sk, int level, int optname,
 		break;
 	case MCAST_MSFILTER:
 	{
+		struct group_filter __user *p = (void __user *)optval;
 		struct group_filter gsf;
+		const int size0 = offsetof(struct group_filter, gf_slist);
+		int num;
 		int err;
 
-		if (len < GROUP_FILTER_SIZE(0))
+		if (len < size0)
 			return -EINVAL;
-		if (copy_from_user(&gsf, optval, GROUP_FILTER_SIZE(0)))
+		if (copy_from_user(&gsf, p, size0))
 			return -EFAULT;
 		if (gsf.gf_group.ss_family != AF_INET6)
 			return -EADDRNOTAVAIL;
+		num = gsf.gf_numsrc;
 		lock_sock(sk);
-		err = ip6_mc_msfget(sk, &gsf,
-			(struct group_filter __user *)optval, optlen);
+		err = ip6_mc_msfget(sk, &gsf, p->gf_slist);
+		if (!err) {
+			if (num > gsf.gf_numsrc)
+				num = gsf.gf_numsrc;
+			if (put_user(GROUP_FILTER_SIZE(num), optlen) ||
+			    copy_to_user(p, &gsf, size0))
+				err = -EFAULT;
+		}
 		release_sock(sk);
 		return err;
 	}
@@ -1428,9 +1546,44 @@ int compat_ipv6_getsockopt(struct sock *sk, int level, int optname,
 	if (level != SOL_IPV6)
 		return -ENOPROTOOPT;
 
-	if (optname == MCAST_MSFILTER)
-		return compat_mc_getsockopt(sk, level, optname, optval, optlen,
-			ipv6_getsockopt);
+	if (optname == MCAST_MSFILTER) {
+		const int size0 = offsetof(struct compat_group_filter, gf_slist);
+		struct compat_group_filter __user *p = (void __user *)optval;
+		struct compat_group_filter gf32;
+		struct group_filter gf;
+		int ulen, err;
+		int num;
+
+		if (get_user(ulen, optlen))
+			return -EFAULT;
+
+		if (ulen < size0)
+			return -EINVAL;
+
+		if (copy_from_user(&gf32, p, size0))
+			return -EFAULT;
+
+		gf.gf_interface = gf32.gf_interface;
+		gf.gf_fmode = gf32.gf_fmode;
+		num = gf.gf_numsrc = gf32.gf_numsrc;
+		gf.gf_group = gf32.gf_group;
+
+		if (gf.gf_group.ss_family != AF_INET6)
+			return -EADDRNOTAVAIL;
+		lock_sock(sk);
+		err = ip6_mc_msfget(sk, &gf, p->gf_slist);
+		release_sock(sk);
+		if (err)
+			return err;
+		if (num > gf.gf_numsrc)
+			num = gf.gf_numsrc;
+		ulen = GROUP_FILTER_SIZE(num) - (sizeof(gf)-sizeof(gf32));
+		if (put_user(ulen, optlen) ||
+		    put_user(gf.gf_fmode, &p->gf_fmode) ||
+		    put_user(gf.gf_numsrc, &p->gf_numsrc))
+			return -EFAULT;
+		return 0;
+	}
 
 	err = do_ipv6_getsockopt(sk, level, optname, optval, optlen,
 				 MSG_CMSG_COMPAT);
diff --git a/net/ipv6/mcast.c b/net/ipv6/mcast.c
index eaa4c2cc2fbb..7e12d2114158 100644
--- a/net/ipv6/mcast.c
+++ b/net/ipv6/mcast.c
@@ -457,7 +457,8 @@ done:
 	return err;
 }
 
-int ip6_mc_msfilter(struct sock *sk, struct group_filter *gsf)
+int ip6_mc_msfilter(struct sock *sk, struct group_filter *gsf,
+		    struct sockaddr_storage *list)
 {
 	const struct in6_addr *group;
 	struct ipv6_mc_socklist *pmc;
@@ -509,10 +510,10 @@ int ip6_mc_msfilter(struct sock *sk, struct group_filter *gsf)
 			goto done;
 		}
 		newpsl->sl_max = newpsl->sl_count = gsf->gf_numsrc;
-		for (i = 0; i < newpsl->sl_count; ++i) {
+		for (i = 0; i < newpsl->sl_count; ++i, ++list) {
 			struct sockaddr_in6 *psin6;
 
-			psin6 = (struct sockaddr_in6 *)&gsf->gf_slist[i];
+			psin6 = (struct sockaddr_in6 *)list;
 			newpsl->sl_addr[i] = psin6->sin6_addr;
 		}
 		err = ip6_mc_add_src(idev, group, gsf->gf_fmode,
@@ -547,7 +548,7 @@ done:
 }
 
 int ip6_mc_msfget(struct sock *sk, struct group_filter *gsf,
-	struct group_filter __user *optval, int __user *optlen)
+	struct sockaddr_storage *p)
 {
 	int err, i, count, copycount;
 	const struct in6_addr *group;
@@ -592,14 +593,10 @@ int ip6_mc_msfget(struct sock *sk, struct group_filter *gsf,
 
 	copycount = count < gsf->gf_numsrc ? count : gsf->gf_numsrc;
 	gsf->gf_numsrc = count;
-	if (put_user(GROUP_FILTER_SIZE(copycount), optlen) ||
-	    copy_to_user(optval, gsf, GROUP_FILTER_SIZE(0))) {
-		return -EFAULT;
-	}
 	/* changes to psl require the socket lock, and a write lock
 	 * on pmc->sflock. We have the socket lock so reading here is safe.
 	 */
-	for (i = 0; i < copycount; i++) {
+	for (i = 0; i < copycount; i++, p++) {
 		struct sockaddr_in6 *psin6;
 		struct sockaddr_storage ss;
 
@@ -607,7 +604,7 @@ int ip6_mc_msfget(struct sock *sk, struct group_filter *gsf,
 		memset(&ss, 0, sizeof(ss));
 		psin6->sin6_family = AF_INET6;
 		psin6->sin6_addr = psl->sl_addr[i];
-		if (copy_to_user(&optval->gf_slist[i], &ss, sizeof(ss)))
+		if (copy_to_user(p, &ss, sizeof(ss)))
 			return -EFAULT;
 	}
 	return 0;