[PATCH 5.4 056/154] ipv6: Fix memleak of nhc_pcpu_rth_output in fib_check_nh_v6_gw().

Greg Kroah-Hartman
2025-04-08T12:04:47Z

From: Kuniyuki Iwashima <kuniyu@amazon.com>

[ 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>
---
net/ipv6/route.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 99908861246d3..d037979f6579f 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -3549,7 +3549,8 @@ int fib6_nh_init(struct net *net, struct fib6_nh *fib6_nh,
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);
--
2.39.5