From: Kuniyuki Iwashima <kuniyu@amazon.com>
Date: Wed, 12 Mar 2025 01:03:25 +0000 (-0700)
Subject: ipv6: Fix memleak of nhc_pcpu_rth_output in fib_check_nh_v6_gw().
X-Git-Tag: v5.10.236~152
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=1bd12dfc058e1e68759d313d7727d68dbc1b8964;p=thirdparty%2Fkernel%2Fstable.git

ipv6: Fix memleak of nhc_pcpu_rth_output in fib_check_nh_v6_gw().

[ Upstream commit 9740890ee20e01f99ff1dde84c63dcf089fabb98 ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---

diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 178c56f6f6185..802386b3937f7 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -3519,7 +3519,8 @@ 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;
 		if (dev)
 			dev_put(dev);