netfilter: nfnetlink_acct: validate NFACCT_QUOTA parameter

BugLink: https://bugs.launchpad.net/bugs/1840335

[ Upstream commit eda3fc50 ]

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 <phil.turnbull@oracle.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Connor Kuehl <connor.kuehl@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

net/netfilter/nfnetlink_acct.c

@@ -97,6 +97,8 @@ nfnl_acct_new(struct sock *nfnl, struct sk_buff *skb,
 			return -EINVAL;
 		if (flags & NFACCT_F_OVERQUOTA)
 			return -EINVAL;
+		if ((flags & NFACCT_F_QUOTA) && !tb[NFACCT_QUOTA])
+			return -EINVAL;
 
 		size += sizeof(u64);
 	}