From c0391b6ab810381df632677a1dcbbbbd63d05b6d Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Thu, 29 Oct 2020 13:50:03 +0100 Subject: netfilter: nf_tables: missing validation from the abort path If userspace does not include the trailing end of batch message, then nfnetlink aborts the transaction. This allows to check that ruleset updates trigger no errors. After this patch, invoking this command from the prerouting chain: # nft -c add rule x y fib saddr . oif type local fails since oif is not supported there. This patch fixes the lack of rule validation from the abort/check path to catch configuration errors such as the one above. Fixes: a654de8fdc18 ("netfilter: nf_tables: fix chain dependency validation") Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nfnetlink.c | 22 ++++++++++++++++++---- 1 file changed, 18 insertions(+), 4 deletions(-) (limited to 'net/netfilter/nfnetlink.c') diff --git a/net/netfilter/nfnetlink.c b/net/netfilter/nfnetlink.c index 2daa1f6ae344..d3df66a39b5e 100644 --- a/net/netfilter/nfnetlink.c +++ b/net/netfilter/nfnetlink.c @@ -333,7 +333,7 @@ static void nfnetlink_rcv_batch(struct sk_buff *skb, struct nlmsghdr *nlh, return netlink_ack(skb, nlh, -EINVAL, NULL); replay: status = 0; - +replay_abort: skb = netlink_skb_clone(oskb, GFP_KERNEL); if (!skb) return netlink_ack(oskb, nlh, -ENOMEM, NULL); @@ -499,7 +499,7 @@ ack: } done: if (status & NFNL_BATCH_REPLAY) { - ss->abort(net, oskb, true); + ss->abort(net, oskb, NFNL_ABORT_AUTOLOAD); nfnl_err_reset(&err_list); kfree_skb(skb); module_put(ss->owner); @@ -510,11 +510,25 @@ done: status |= NFNL_BATCH_REPLAY; goto done; } else if (err) { - ss->abort(net, oskb, false); + ss->abort(net, oskb, NFNL_ABORT_NONE); netlink_ack(oskb, nlmsg_hdr(oskb), err, NULL); } } else { - ss->abort(net, oskb, false); + enum nfnl_abort_action abort_action; + + if (status & NFNL_BATCH_FAILURE) + abort_action = NFNL_ABORT_NONE; + else + abort_action = NFNL_ABORT_VALIDATE; + + err = ss->abort(net, oskb, abort_action); + if (err == -EAGAIN) { + nfnl_err_reset(&err_list); + kfree_skb(skb); + module_put(ss->owner); + status |= NFNL_BATCH_FAILURE; + goto replay_abort; + } } if (ss->cleanup) ss->cleanup(net); -- cgit v1.2.3-59-g8ed1b