Subject: [PATCH AUTOSEL 4.19 31/52] netfilter: xt_physdev: Fix spurious error message in physdev_mt_check

From: Sasha Levin <[email-masked]>
Date: Wed, 4 Sep 2019 11:59:43 -0400

From: Todd Seidelmann <[email-masked]>

[ 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 <[email-masked]>
Acked-by: Florian Westphal <[email-masked]>
Signed-off-by: Pablo Neira Ayuso <[email-masked]>
Signed-off-by: Sasha Levin <[email-masked]>
---
 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