diff mbox series

[net-next,13/14] netfilter: flowtable: teardown flow if cached mtu is stale

Message ID 20250116171902.1783620-14-pablo@netfilter.org (mailing list archive)
State New
Delegated to: Netdev Maintainers
Headers show
Series [net-next,01/14] netfilter: nf_tables: fix set size with rbtree backend | expand

Checks

Context Check Description
netdev/series_format success Pull request is its own cover letter
netdev/tree_selection success Clearly marked for net-next
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 1 this patch: 1
netdev/build_tools success No tools touched, skip
netdev/cc_maintainers warning 3 maintainers not CCed: coreteam@netfilter.org horms@kernel.org kadlec@netfilter.org
netdev/build_clang success Errors and warnings before: 2 this patch: 2
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 2 this patch: 2
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 22 lines checked
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Pablo Neira Ayuso Jan. 16, 2025, 5:19 p.m. UTC 
Tear down the flow entry in the unlikely case that the interface mtu
changes, this gives the flow a chance to refresh the cached mtu,
otherwise such refresh does not occur until flow entry expires.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/netfilter/nf_flow_table_ip.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)
diff mbox series

Patch

diff --git a/net/netfilter/nf_flow_table_ip.c b/net/netfilter/nf_flow_table_ip.c
index 98edcaa37b38..a22856106383 100644
--- a/net/netfilter/nf_flow_table_ip.c
+++ b/net/netfilter/nf_flow_table_ip.c
@@ -377,8 +377,10 @@  static int nf_flow_offload_forward(struct nf_flowtable_ctx *ctx,
 	flow = container_of(tuplehash, struct flow_offload, tuplehash[dir]);
 
 	mtu = flow->tuplehash[dir].tuple.mtu + ctx->offset;
-	if (unlikely(nf_flow_exceeds_mtu(skb, mtu)))
+	if (unlikely(nf_flow_exceeds_mtu(skb, mtu))) {
+		flow_offload_teardown(flow);
 		return 0;
+	}
 
 	iph = (struct iphdr *)(skb_network_header(skb) + ctx->offset);
 	thoff = (iph->ihl * 4) + ctx->offset;
@@ -656,8 +658,10 @@  static int nf_flow_offload_ipv6_forward(struct nf_flowtable_ctx *ctx,
 	flow = container_of(tuplehash, struct flow_offload, tuplehash[dir]);
 
 	mtu = flow->tuplehash[dir].tuple.mtu + ctx->offset;
-	if (unlikely(nf_flow_exceeds_mtu(skb, mtu)))
+	if (unlikely(nf_flow_exceeds_mtu(skb, mtu))) {
+		flow_offload_teardown(flow);
 		return 0;
+	}
 
 	ip6h = (struct ipv6hdr *)(skb_network_header(skb) + ctx->offset);
 	thoff = sizeof(*ip6h) + ctx->offset;