net: microchip: vcap api: Fix possible memory leak for vcap_dup_rule()

Inject fault When select CONFIG_VCAP_KUNIT_TEST, the below memory leak
occurs. If kzalloc() for duprule succeeds, but the following
kmemdup() fails, the duprule, ckf and caf memory will be leaked. So kfree
them in the error path.

unreferenced object 0xffff122744c50600 (size 192):
  comm "kunit_try_catch", pid 346, jiffies 4294896122 (age 911.812s)
  hex dump (first 32 bytes):
    10 27 00 00 04 00 00 00 1e 00 00 00 2c 01 00 00  .'..........,...
    00 00 00 00 00 00 00 00 18 06 c5 44 27 12 ff ff  ...........D'...
  backtrace:
    [<00000000394b0db8>] __kmem_cache_alloc_node+0x274/0x2f8
    [<0000000001bedc67>] kmalloc_trace+0x38/0x88
    [<00000000b0612f98>] vcap_dup_rule+0x50/0x460
    [<000000005d2d3aca>] vcap_add_rule+0x8cc/0x1038
    [<00000000eef9d0f8>] test_vcap_xn_rule_creator.constprop.0.isra.0+0x238/0x494
    [<00000000cbda607b>] vcap_api_rule_remove_in_front_test+0x1ac/0x698
    [<00000000c8766299>] kunit_try_run_case+0xe0/0x20c
    [<00000000c4fe9186>] kunit_generic_run_threadfn_adapter+0x50/0x94
    [<00000000f6864acf>] kthread+0x2e8/0x374
    [<0000000022e639b3>] ret_from_fork+0x10/0x20

Fixes: 814e7693 ("net: microchip: vcap api: Add a storage state to a VCAP rule")
Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/microchip/vcap/vcap_api.c

@@ -1021,18 +1021,32 @@ static struct vcap_rule_internal *vcap_dup_rule(struct vcap_rule_internal *ri,
 	list_for_each_entry(ckf, &ri->data.keyfields, ctrl.list) {
 		newckf = kmemdup(ckf, sizeof(*newckf), GFP_KERNEL);
 		if (!newckf)
-			return ERR_PTR(-ENOMEM);
+			goto err;
 		list_add_tail(&newckf->ctrl.list, &duprule->data.keyfields);
 	}
 
 	list_for_each_entry(caf, &ri->data.actionfields, ctrl.list) {
 		newcaf = kmemdup(caf, sizeof(*newcaf), GFP_KERNEL);
 		if (!newcaf)
-			return ERR_PTR(-ENOMEM);
+			goto err;
 		list_add_tail(&newcaf->ctrl.list, &duprule->data.actionfields);
 	}
 
 	return duprule;
+
+err:
+	list_for_each_entry_safe(ckf, newckf, &duprule->data.keyfields, ctrl.list) {
+		list_del(&ckf->ctrl.list);
+		kfree(ckf);
+	}
+
+	list_for_each_entry_safe(caf, newcaf, &duprule->data.actionfields, ctrl.list) {
+		list_del(&caf->ctrl.list);
+		kfree(caf);
+	}
+
+	kfree(duprule);
+	return ERR_PTR(-ENOMEM);
 }
 
 static void vcap_apply_width(u8 *dst, int width, int bytes)