util/linuxfw: don't panic on delete of chain in nil table

Fixes #10003 Change-Id: Ibef8326ffbbef5ba59caa21baa1f2cf4f5185971 Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2023-10-27 17:28:35 -07:00
1 changed files with 5 additions and 0 deletions
--- a/util/linuxfw/nftables_runner.go
+++ b/util/linuxfw/nftables_runner.go
@@ -860,7 +860,12 @@ func (n *nftablesRunner) createDummyPostroutingChains() (retErr error) {
 }

 // deleteChainIfExists deletes a chain if it exists.
+//
+// If table is nil, it returns nil.
 func deleteChainIfExists(c *nftables.Conn, table *nftables.Table, name string) error {
+	if table == nil {
+		return nil
+	}
 	chain, err := getChainFromTable(c, table, name)
 	if err != nil && !errors.Is(err, errorChainNotFound{table.Name, name}) {
 		return fmt.Errorf("get chain: %w", err)