netfilter: nfnetlink_acct: validate NFACCT_QUOTA parameter

If a quota bit is set in NFACCT_FLAGS but the NFACCT_QUOTA parameter is
missing then a NULL pointer dereference is triggered. CAP_NET_ADMIN is
required to trigger the bug.

Signed-off-by: Phil Turnbull <[email protected]>
Signed-off-by: Pablo Neira Ayuso <[email protected]>

diff --git a/net/netfilter/nfnetlink_acct.c b/net/netfilter/nfnetlink_acct.c
index 4c2b4c0c4d5fa4ac209ab85020e97e14ed716ab9..dbd0803b18273bbf3b37e7f0f5bfae87d5acfc2d 100644 (file)
--- a/net/netfilter/nfnetlink_acct.c
+++ b/net/netfilter/nfnetlink_acct.c
@@ -96,6 +96,8 @@ static int nfnl_acct_new(struct net *net, struct sock *nfnl,
                        return -EINVAL;
                if (flags & NFACCT_F_OVERQUOTA)
                        return -EINVAL;
+               if ((flags & NFACCT_F_QUOTA) && !tb[NFACCT_QUOTA])
+                       return -EINVAL;
 
                size += sizeof(u64);
        }