[PATCH 4.4 122/230] netfilter: nfnetlink_acct: validate NFACCT_FILTER parameters

[Greg Kroah-Hartman]

4.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Phil Turnbull <phil.turnbull@xxxxxxxxxx>

commit 017b1b6d28c479f1ad9a7a41f775545a3e1cba35 upstream.

nfacct_filter_alloc doesn't validate the NFACCT_FILTER_MASK and
NFACCT_FILTER_VALUE parameters which can trigger a NULL pointer
dereference. CAP_NET_ADMIN is required to trigger the bug.

Signed-off-by: Phil Turnbull <phil.turnbull@xxxxxxxxxx>
Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
Cc: Zubin Mithra <zsm@xxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 net/netfilter/nfnetlink_acct.c |    3 +++
 1 file changed, 3 insertions(+)

--- a/net/netfilter/nfnetlink_acct.c
+++ b/net/netfilter/nfnetlink_acct.c
@@ -243,6 +243,9 @@ nfacct_filter_alloc(const struct nlattr
 	if (err < 0)
 		return ERR_PTR(err);
 
+	if (!tb[NFACCT_FILTER_MASK] || !tb[NFACCT_FILTER_VALUE])
+		return ERR_PTR(-EINVAL);
+
 	filter = kzalloc(sizeof(struct nfacct_filter), GFP_KERNEL);
 	if (!filter)
 		return ERR_PTR(-ENOMEM);