[PATCH 4.19 47/79] netfilter: xt_physdev: Fix spurious error message in physdev_mt_check

Greg Kroah-Hartman
2019-09-19T22:15:15Z

From: Todd Seidelmann <tseidelmann@linode.com>

[ Upstream commit 3cf2f450fff304be9cf4868bf0df17f253bc5b1c ]

Simplify the check in physdev_mt_check() to emit an error message
only when passed an invalid chain (ie, NF_INET_LOCAL_OUT).
This avoids cluttering up the log with errors against valid rules.

For large/heavily modified rulesets, current behavior can quickly
overwhelm the ring buffer, because this function gets called on
every change, regardless of the rule that was changed.

Signed-off-by: Todd Seidelmann <tseidelmann@linode.com>
Acked-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/netfilter/xt_physdev.c | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/net/netfilter/xt_physdev.c b/net/netfilter/xt_physdev.c
index 05f00fb20b047..cd15ea79e3e2a 100644
--- a/net/netfilter/xt_physdev.c
+++ b/net/netfilter/xt_physdev.c
@@ -104,11 +104,9 @@ static int physdev_mt_check(const struct xt_mtchk_param *par)
if (info->bitmask & (XT_PHYSDEV_OP_OUT | XT_PHYSDEV_OP_ISOUT) &&
(!(info->bitmask & XT_PHYSDEV_OP_BRIDGED) ||
info->invert & XT_PHYSDEV_OP_BRIDGED) &&
- par->hook_mask & ((1 << NF_INET_LOCAL_OUT) |
- (1 << NF_INET_FORWARD) | (1 << NF_INET_POST_ROUTING))) {
+ par->hook_mask & (1 << NF_INET_LOCAL_OUT)) {
pr_info_ratelimited("--physdev-out and --physdev-is-out only supported in the FORWARD and POSTROUTING chains with bridged traffic\n");
- if (par->hook_mask & (1 << NF_INET_LOCAL_OUT))
- return -EINVAL;
+ return -EINVAL;
}

if (!brnf_probed) {
--
2.20.1