ipv6: Fix memleak of nhc_pcpu_rth_output in fib_check_nh_v6_gw().

fib_check_nh_v6_gw() expects that fib6_nh_init() cleans up everything
when it fails.

Commit 7dd73168e273 ("ipv6: Always allocate pcpu memory in a fib6_nh")
moved fib_nh_common_init() before alloc_percpu_gfp() within fib6_nh_init()
but forgot to add cleanup for fib6_nh->nh_common.nhc_pcpu_rth_output in
case it fails to allocate fib6_nh->rt6i_pcpu, resulting in memleak.

Let's call fib_nh_common_release() and clear nhc_pcpu_rth_output in the
error path.

Note that we can remove the fib6_nh_release() call in nh_create_ipv6()
later in net-next.git.

Fixes: 7dd73168e273 ("ipv6: Always allocate pcpu memory in a fib6_nh")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20250312010333.56001-1-kuniyu@amazon.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index ef2d23a1e3d532f5db37ca94ca482c5522dddffc..bc6bcf5d7133e9b1566ad8b471d781fc10b4f4c7 100644 (file)
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -3644,7 +3644,8 @@ out:
                in6_dev_put(idev);
 
        if (err) {
-               lwtstate_put(fib6_nh->fib_nh_lws);
+               fib_nh_common_release(&fib6_nh->nh_common);
+               fib6_nh->nh_common.nhc_pcpu_rth_output = NULL;
                fib6_nh->fib_nh_lws = NULL;
                netdev_put(dev, dev_tracker);
        }