Patch "netfilter: x_tables: introduce and use xt_copy_counters_from_user" has been added to the 4.4-stable tree

[<gregkh@linuxfoundation.org>]

This is a note to let you know that I've just added the patch titled

    netfilter: x_tables: introduce and use xt_copy_counters_from_user

to the 4.4-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     netfilter-x_tables-introduce-and-use-xt_copy_counters_from_user.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From d7591f0c41ce3e67600a982bab6989ef0f07b3ce Mon Sep 17 00:00:00 2001
From: Florian Westphal <fw@strlen.de>
Date: Fri, 1 Apr 2016 15:37:59 +0200
Subject: netfilter: x_tables: introduce and use xt_copy_counters_from_user

From: Florian Westphal <fw@strlen.de>

commit d7591f0c41ce3e67600a982bab6989ef0f07b3ce upstream.

The three variants use same copy&pasted code, condense this into a
helper and use that.

Make sure info.name is 0-terminated.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 include/linux/netfilter/x_tables.h |    3 +
 net/ipv4/netfilter/arp_tables.c    |   48 ++----------------------
 net/ipv4/netfilter/ip_tables.c     |   48 ++----------------------
 net/ipv6/netfilter/ip6_tables.c    |   49 ++----------------------
 net/netfilter/x_tables.c           |   74 +++++++++++++++++++++++++++++++++++++
 5 files changed, 92 insertions(+), 130 deletions(-)

--- a/include/linux/netfilter/x_tables.h
+++ b/include/linux/netfilter/x_tables.h
@@ -248,6 +248,9 @@ int xt_check_match(struct xt_mtchk_param
 int xt_check_target(struct xt_tgchk_param *, unsigned int size, u_int8_t proto,
 		    bool inv_proto);
 
+void *xt_copy_counters_from_user(const void __user *user, unsigned int len,
+				 struct xt_counters_info *info, bool compat);
+
 struct xt_table *xt_register_table(struct net *net,
 				   const struct xt_table *table,
 				   struct xt_table_info *bootstrap,
--- a/net/ipv4/netfilter/arp_tables.c
+++ b/net/ipv4/netfilter/arp_tables.c
@@ -1130,55 +1130,17 @@ static int do_add_counters(struct net *n
 	unsigned int i;
 	struct xt_counters_info tmp;
 	struct xt_counters *paddc;
-	unsigned int num_counters;
-	const char *name;
-	int size;
-	void *ptmp;
 	struct xt_table *t;
 	const struct xt_table_info *private;
 	int ret = 0;
 	struct arpt_entry *iter;
 	unsigned int addend;
-#ifdef CONFIG_COMPAT
-	struct compat_xt_counters_info compat_tmp;
 
-	if (compat) {
-		ptmp = &compat_tmp;
-		size = sizeof(struct compat_xt_counters_info);
-	} else
-#endif
-	{
-		ptmp = &tmp;
-		size = sizeof(struct xt_counters_info);
-	}
-
-	if (copy_from_user(ptmp, user, size) != 0)
-		return -EFAULT;
-
-#ifdef CONFIG_COMPAT
-	if (compat) {
-		num_counters = compat_tmp.num_counters;
-		name = compat_tmp.name;
-	} else
-#endif
-	{
-		num_counters = tmp.num_counters;
-		name = tmp.name;
-	}
-
-	if (len != size + num_counters * sizeof(struct xt_counters))
-		return -EINVAL;
-
-	paddc = vmalloc(len - size);
-	if (!paddc)
-		return -ENOMEM;
-
-	if (copy_from_user(paddc, user + size, len - size) != 0) {
-		ret = -EFAULT;
-		goto free;
-	}
+	paddc = xt_copy_counters_from_user(user, len, &tmp, compat);
+	if (IS_ERR(paddc))
+		return PTR_ERR(paddc);
 
-	t = xt_find_table_lock(net, NFPROTO_ARP, name);
+	t = xt_find_table_lock(net, NFPROTO_ARP, tmp.name);
 	if (IS_ERR_OR_NULL(t)) {
 		ret = t ? PTR_ERR(t) : -ENOENT;
 		goto free;
@@ -1186,7 +1148,7 @@ static int do_add_counters(struct net *n
 
 	local_bh_disable();
 	private = t->private;
-	if (private->number != num_counters) {
+	if (private->number != tmp.num_counters) {
 		ret = -EINVAL;
 		goto unlock_up_free;
 	}
--- a/net/ipv4/netfilter/ip_tables.c
+++ b/net/ipv4/netfilter/ip_tables.c
@@ -1313,55 +1313,17 @@ do_add_counters(struct net *net, const v
 	unsigned int i;
 	struct xt_counters_info tmp;
 	struct xt_counters *paddc;
-	unsigned int num_counters;
-	const char *name;
-	int size;
-	void *ptmp;
 	struct xt_table *t;
 	const struct xt_table_info *private;
 	int ret = 0;
 	struct ipt_entry *iter;
 	unsigned int addend;
-#ifdef CONFIG_COMPAT
-	struct compat_xt_counters_info compat_tmp;
 
-	if (compat) {
-		ptmp = &compat_tmp;
-		size = sizeof(struct compat_xt_counters_info);
-	} else
-#endif
-	{
-		ptmp = &tmp;
-		size = sizeof(struct xt_counters_info);
-	}
-
-	if (copy_from_user(ptmp, user, size) != 0)
-		return -EFAULT;
-
-#ifdef CONFIG_COMPAT
-	if (compat) {
-		num_counters = compat_tmp.num_counters;
-		name = compat_tmp.name;
-	} else
-#endif
-	{
-		num_counters = tmp.num_counters;
-		name = tmp.name;
-	}
-
-	if (len != size + num_counters * sizeof(struct xt_counters))
-		return -EINVAL;
-
-	paddc = vmalloc(len - size);
-	if (!paddc)
-		return -ENOMEM;
-
-	if (copy_from_user(paddc, user + size, len - size) != 0) {
-		ret = -EFAULT;
-		goto free;
-	}
+	paddc = xt_copy_counters_from_user(user, len, &tmp, compat);
+	if (IS_ERR(paddc))
+		return PTR_ERR(paddc);
 
-	t = xt_find_table_lock(net, AF_INET, name);
+	t = xt_find_table_lock(net, AF_INET, tmp.name);
 	if (IS_ERR_OR_NULL(t)) {
 		ret = t ? PTR_ERR(t) : -ENOENT;
 		goto free;
@@ -1369,7 +1331,7 @@ do_add_counters(struct net *net, const v
 
 	local_bh_disable();
 	private = t->private;
-	if (private->number != num_counters) {
+	if (private->number != tmp.num_counters) {
 		ret = -EINVAL;
 		goto unlock_up_free;
 	}
--- a/net/ipv6/netfilter/ip6_tables.c
+++ b/net/ipv6/netfilter/ip6_tables.c
@@ -1325,55 +1325,16 @@ do_add_counters(struct net *net, const v
 	unsigned int i;
 	struct xt_counters_info tmp;
 	struct xt_counters *paddc;
-	unsigned int num_counters;
-	char *name;
-	int size;
-	void *ptmp;
 	struct xt_table *t;
 	const struct xt_table_info *private;
 	int ret = 0;
 	struct ip6t_entry *iter;
 	unsigned int addend;
-#ifdef CONFIG_COMPAT
-	struct compat_xt_counters_info compat_tmp;
 
-	if (compat) {
-		ptmp = &compat_tmp;
-		size = sizeof(struct compat_xt_counters_info);
-	} else
-#endif
-	{
-		ptmp = &tmp;
-		size = sizeof(struct xt_counters_info);
-	}
-
-	if (copy_from_user(ptmp, user, size) != 0)
-		return -EFAULT;
-
-#ifdef CONFIG_COMPAT
-	if (compat) {
-		num_counters = compat_tmp.num_counters;
-		name = compat_tmp.name;
-	} else
-#endif
-	{
-		num_counters = tmp.num_counters;
-		name = tmp.name;
-	}
-
-	if (len != size + num_counters * sizeof(struct xt_counters))
-		return -EINVAL;
-
-	paddc = vmalloc(len - size);
-	if (!paddc)
-		return -ENOMEM;
-
-	if (copy_from_user(paddc, user + size, len - size) != 0) {
-		ret = -EFAULT;
-		goto free;
-	}
-
-	t = xt_find_table_lock(net, AF_INET6, name);
+	paddc = xt_copy_counters_from_user(user, len, &tmp, compat);
+	if (IS_ERR(paddc))
+		return PTR_ERR(paddc);
+	t = xt_find_table_lock(net, AF_INET6, tmp.name);
 	if (IS_ERR_OR_NULL(t)) {
 		ret = t ? PTR_ERR(t) : -ENOENT;
 		goto free;
@@ -1381,7 +1342,7 @@ do_add_counters(struct net *net, const v
 
 	local_bh_disable();
 	private = t->private;
-	if (private->number != num_counters) {
+	if (private->number != tmp.num_counters) {
 		ret = -EINVAL;
 		goto unlock_up_free;
 	}
--- a/net/netfilter/x_tables.c
+++ b/net/netfilter/x_tables.c
@@ -751,6 +751,80 @@ int xt_check_target(struct xt_tgchk_para
 }
 EXPORT_SYMBOL_GPL(xt_check_target);
 
+/**
+ * xt_copy_counters_from_user - copy counters and metadata from userspace
+ *
+ * @user: src pointer to userspace memory
+ * @len: alleged size of userspace memory
+ * @info: where to store the xt_counters_info metadata
+ * @compat: true if we setsockopt call is done by 32bit task on 64bit kernel
+ *
+ * Copies counter meta data from @user and stores it in @info.
+ *
+ * vmallocs memory to hold the counters, then copies the counter data
+ * from @user to the new memory and returns a pointer to it.
+ *
+ * If @compat is true, @info gets converted automatically to the 64bit
+ * representation.
+ *
+ * The metadata associated with the counters is stored in @info.
+ *
+ * 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, bool compat)
+{
+	void *mem;
+	u64 size;
+
+#ifdef CONFIG_COMPAT
+	if (compat) {
+		/* structures only differ in size due to alignment */
+		struct compat_xt_counters_info compat_tmp;
+
+		if (len <= sizeof(compat_tmp))
+			return ERR_PTR(-EINVAL);
+
+		len -= sizeof(compat_tmp);
+		if (copy_from_user(&compat_tmp, user, sizeof(compat_tmp)) != 0)
+			return ERR_PTR(-EFAULT);
+
+		strlcpy(info->name, compat_tmp.name, sizeof(info->name));
+		info->num_counters = compat_tmp.num_counters;
+		user += sizeof(compat_tmp);
+	} else
+#endif
+	{
+		if (len <= sizeof(*info))
+			return ERR_PTR(-EINVAL);
+
+		len -= sizeof(*info);
+		if (copy_from_user(info, user, sizeof(*info)) != 0)
+			return ERR_PTR(-EFAULT);
+
+		info->name[sizeof(info->name) - 1] = '\0';
+		user += sizeof(*info);
+	}
+
+	size = sizeof(struct xt_counters);
+	size *= info->num_counters;
+
+	if (size != (u64)len)
+		return ERR_PTR(-EINVAL);
+
+	mem = vmalloc(len);
+	if (!mem)
+		return ERR_PTR(-ENOMEM);
+
+	if (copy_from_user(mem, user, len) == 0)
+		return mem;
+
+	vfree(mem);
+	return ERR_PTR(-EFAULT);
+}
+EXPORT_SYMBOL_GPL(xt_copy_counters_from_user);
+
 #ifdef CONFIG_COMPAT
 int xt_compat_target_offset(const struct xt_target *target)
 {


Patches currently in stable-queue which might be from fw@strlen.de are

queue-4.4/netfilter-x_tables-validate-targets-of-jumps.patch
queue-4.4/netfilter-x_tables-introduce-and-use-xt_copy_counters_from_user.patch
queue-4.4/netfilter-arp_tables-simplify-translate_compat_table-args.patch
queue-4.4/netfilter-x_tables-validate-e-target_offset-early.patch
queue-4.4/netfilter-x_tables-assert-minimum-target-size.patch
queue-4.4/netfilter-ip6_tables-simplify-translate_compat_table-args.patch
queue-4.4/netfilter-x_tables-check-for-bogus-target-offset.patch
queue-4.4/netfilter-x_tables-add-compat-version-of-xt_check_entry_offsets.patch
queue-4.4/netfilter-x_tables-don-t-reject-valid-target-size-on-some-architectures.patch
queue-4.4/netfilter-x_tables-check-standard-target-size-too.patch
queue-4.4/netfilter-x_tables-xt_compat_match_from_user-doesn-t-need-a-retval.patch
queue-4.4/netfilter-x_tables-do-compat-validation-via-translate_table.patch
queue-4.4/netfilter-x_tables-add-and-use-xt_check_entry_offsets.patch
queue-4.4/netfilter-x_tables-don-t-move-to-non-existent-next-rule.patch
queue-4.4/netfilter-x_tables-kill-check_entry-helper.patch
queue-4.4/netfilter-x_tables-validate-all-offsets-and-sizes-in-a-rule.patch
queue-4.4/netfilter-x_tables-make-sure-e-next_offset-covers-remaining-blob-size.patch
queue-4.4/netfilter-ip_tables-simplify-translate_compat_table-args.patch
queue-4.4/netfilter-x_tables-fix-unconditional-helper.patch